Resolves checkstyle errors for remaining m (#1090)

* Reduces checkstyle errors in marker

* Reduces checkstyle errors in master-worker-pattern

* Reduces checkstyle errors in mediator

* Reduces checkstyle errors in memento

* Reduces checkstyle errors in model-view-controller

* Reduces checkstyle errors in model-view-presenter

* Reduces checkstyle errors in module

* Reduces checkstyle errors in monad

* Reduces checkstyle errors in monostate

* Reduces checkstyle errors in multiton

* Reduces checkstyle errors in mute-idiom

* Reduces checkstyle errors in mutex

marker/src/main/java/App.java

@@ -25,27 +25,23 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Created by Alexis on 28-Apr-17.
+ * Created by Alexis on 28-Apr-17. With Marker interface idea is to make empty interface and extend
- * With Marker interface idea is to make empty interface and extend it.
+ * it. Basically it is just to identify the special objects from normal objects. Like in case of
- * Basically it is just to identify the special objects from normal objects.
+ * serialization , objects that need to be serialized must implement serializable interface (it is
- * Like in case of serialization , objects that need to be serialized must implement serializable interface
+ * empty interface) and down the line writeObject() method must be checking if it is a instance of
- * (it is empty interface) and down the line writeObject() method must be checking
+ * serializable or not.
- * if it is a instance of serializable or not.
+ *
- * <p>
+ * <p>Marker interface vs annotation Marker interfaces and marker annotations both have their uses,
- * Marker interface vs annotation
+ * neither of them is obsolete or always better then the other one. If you want to define a type
- * Marker interfaces and marker annotations both have their uses,
+ * that does not have any new methods associated with it, a marker interface is the way to go. If
- * neither of them is obsolete or always better then the other one.
+ * you want to mark program elements other than classes and interfaces, to allow for the possibility
- * If you want to define a type that does not have any new methods associated with it,
+ * of adding more information to the marker in the future, or to fit the marker into a framework
- * a marker interface is the way to go.
+ * that already makes heavy use of annotation types, then a marker annotation is the correct choice
- * If you want to mark program elements other than classes and interfaces,
- * to allow for the possibility of adding more information to the marker in the future,
- * or to fit the marker into a framework that already makes heavy use of annotation types,
- * then a marker annotation is the correct choice
  */
 public class App {
 
   /**
-   * Program entry point
+   * Program entry point.
    *
    * @param args command line args
    */

marker/src/main/java/Guard.java

@@ -25,7 +25,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Class defining Guard
+ * Class defining Guard.
  */
 public class Guard implements Permission {
 

marker/src/main/java/Permission.java

@@ -22,8 +22,7 @@
  */
 
 /**
- * Interface without any methods
+ * Interface without any methods Marker interface is based on that assumption.
- * Marker interface is based on that assumption
  */
 public interface Permission {
 }

marker/src/main/java/Thief.java

@@ -25,7 +25,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Class defining Thief
+ * Class defining Thief.
  */
 public class Thief {
 

master-worker-pattern/src/main/java/com/iluwatar/masterworker/App.java

@@ -28,30 +28,37 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * <p>The <b><em>Master-Worker</em></b> pattern is used when the problem at hand can be solved by dividing into 
+ * <p>The <b><em>Master-Worker</em></b> pattern is used when the problem at hand can be solved by
- * multiple parts which need to go through the same computation and may need to be aggregated to get final result.
+ * dividing into
- * Parallel processing is performed using a system consisting of a master and some number of workers, where a 
+ * multiple parts which need to go through the same computation and may need to be aggregated to get
- * master divides the work among the workers, gets the result back from them and assimilates all the results to
+ * final result. Parallel processing is performed using a system consisting of a master and some
- * give final result. The only communication is between the master and the worker - none of the workers communicate
+ * number of workers, where a master divides the work among the workers, gets the result back from
- * among one another and the user only communicates with the master to get required job done.</p>
+ * them and assimilates all the results to give final result. The only communication is between the
- * <p>In our example, we have generic abstract classes {@link MasterWorker}, {@link Master} and {@link Worker} which
+ * master and the worker - none of the workers communicate among one another and the user only
- * have to be extended by the classes which will perform the specific job at hand (in this case finding transpose of
+ * communicates with the master to get required job done.</p>
- * matrix, done by {@link ArrayTransposeMasterWorker}, {@link ArrayTransposeMaster} and {@link ArrayTransposeWorker}).
+ * <p>In our example, we have generic abstract classes {@link MasterWorker}, {@link Master} and
- * The Master class divides the work into parts to be given to the workers, collects the results from the workers and
+ * {@link Worker} which
- * aggregates it when all workers have responded before returning the solution. The Worker class extends the Thread
+ * have to be extended by the classes which will perform the specific job at hand (in this case
- * class to enable parallel processing, and does the work once the data has been received from the Master. The
+ * finding transpose of matrix, done by {@link ArrayTransposeMasterWorker}, {@link
- * MasterWorker contains a reference to the Master class, gets the input from the App and passes it on to the Master.
+ * ArrayTransposeMaster} and {@link ArrayTransposeWorker}). The Master class divides the work into
- * These 3 classes define the system which computes the result. We also have 2 abstract classes {@link Input} and
+ * parts to be given to the workers, collects the results from the workers and aggregates it when
- * {@link Result}, which contain the input data and result data respectively. The Input class also has an abstract
+ * all workers have responded before returning the solution. The Worker class extends the Thread
- * method divideData which defines how the data is to be divided into segments. These classes are extended by
+ * class to enable parallel processing, and does the work once the data has been received from the
- * {@link ArrayInput} and {@link ArrayResult}.</p>
+ * Master. The MasterWorker contains a reference to the Master class, gets the input from the App
+ * and passes it on to the Master. These 3 classes define the system which computes the result. We
+ * also have 2 abstract classes {@link Input} and {@link Result}, which contain the input data and
+ * result data respectively. The Input class also has an abstract method divideData which defines
+ * how the data is to be divided into segments. These classes are extended by {@link ArrayInput} and
+ * {@link ArrayResult}.</p>
  */
 
 public class App {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
+
   /**
    * Program entry point.
+   *
    * @param args command line args
    */
 
@@ -59,9 +66,9 @@ public class App {
     ArrayTransposeMasterWorker mw = new ArrayTransposeMasterWorker();
     int rows = 10;
     int columns = 20;
-    int[][] inputMatrix = ArrayUtilityMethods.createRandomIntMatrix(rows,columns);    
+    int[][] inputMatrix = ArrayUtilityMethods.createRandomIntMatrix(rows, columns);
     ArrayInput input = new ArrayInput(inputMatrix);
-    ArrayResult result = (ArrayResult) mw.getResult(input);    
+    ArrayResult result = (ArrayResult) mw.getResult(input);
     if (result != null) {
       ArrayUtilityMethods.printMatrix(inputMatrix);
       ArrayUtilityMethods.printMatrix(result.data);

master-worker-pattern/src/main/java/com/iluwatar/masterworker/ArrayInput.java

@@ -27,8 +27,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 
 /**
- *Class ArrayInput extends abstract class {@link Input} and contains data
+ * Class ArrayInput extends abstract class {@link Input} and contains data of type int[][].
- *of type int[][].
  */
 
 public class ArrayInput extends Input<int[][]> {
@@ -36,7 +35,7 @@ public class ArrayInput extends Input<int[][]> {
   public ArrayInput(int[][] data) {
     super(data);
   }
-  
+
   static int[] makeDivisions(int[][] data, int num) {
     int initialDivision = data.length / num; //equally dividing
     int[] divisions = new int[num];
@@ -81,6 +80,6 @@ public class ArrayInput extends Input<int[][]> {
         }
       }
       return result;
-    }    
+    }
-  } 
+  }
 }

master-worker-pattern/src/main/java/com/iluwatar/masterworker/ArrayResult.java

@@ -24,8 +24,7 @@
 package com.iluwatar.masterworker;
 
 /**
- *Class ArrayResult extends abstract class {@link Result} and contains data
+ * Class ArrayResult extends abstract class {@link Result} and contains data of type int[][].
- *of type int[][].
  */
 
 public class ArrayResult extends Result<int[][]> {

master-worker-pattern/src/main/java/com/iluwatar/masterworker/ArrayUtilityMethods.java

@@ -23,23 +23,23 @@
 
 package com.iluwatar.masterworker;
 
+import java.util.Random;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.Random;
-
 /**
- *Class ArrayUtilityMethods has some utility methods for matrices and arrays.
+ * Class ArrayUtilityMethods has some utility methods for matrices and arrays.
  */
 
 public class ArrayUtilityMethods {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(ArrayUtilityMethods.class);
-  
+
   private static final Random RANDOM = new Random();
+
   /**
-   * Method arraysSame compares 2 arrays @param a1 and @param a2
+   * Method arraysSame compares 2 arrays @param a1 and @param a2 and @return whether their values
-   * and @return whether their values are equal (boolean).
+   * are equal (boolean).
    */
 
   public static boolean arraysSame(int[] a1, int[] a2) {
@@ -61,10 +61,10 @@ public class ArrayUtilityMethods {
   }
 
   /**
-   * Method matricesSame compares 2 matrices @param m1 and @param m2
+   * Method matricesSame compares 2 matrices @param m1 and @param m2 and @return whether their
-   * and @return whether their values are equal (boolean).
+   * values are equal (boolean).
    */
-  
+
   public static boolean matricesSame(int[][] m1, int[][] m2) {
     if (m1.length != m2.length) {
       return false;
@@ -81,12 +81,12 @@ public class ArrayUtilityMethods {
       return answer;
     }
   }
-  
+
   /**
-   * Method createRandomIntMatrix creates a random matrix of size @param rows
+   * Method createRandomIntMatrix creates a random matrix of size @param rows and @param columns.
-   * and @param columns @return it (int[][]).
+   *
+   * @return it (int[][]).
    */
-  
   public static int[][] createRandomIntMatrix(int rows, int columns) {
     int[][] matrix = new int[rows][columns];
     for (int i = 0; i < rows; i++) {
@@ -97,11 +97,11 @@ public class ArrayUtilityMethods {
     }
     return matrix;
   }
-  
+
   /**
    * Method printMatrix prints input matrix @param matrix.
    */
-  
+
   public static void printMatrix(int[][] matrix) {
     //prints out int[][]
     for (int i = 0; i < matrix.length; i++) {
@@ -111,5 +111,5 @@ public class ArrayUtilityMethods {
       LOGGER.info("");
     }
   }
-  
+
 }

master-worker-pattern/src/main/java/com/iluwatar/masterworker/Input.java

@@ -26,18 +26,19 @@ package com.iluwatar.masterworker;
 import java.util.ArrayList;
 
 /**
- *The abstract Input class, having 1 public field which contains input data,
+ * The abstract Input class, having 1 public field which contains input data, and abstract method
- *and abstract method divideData.
+ * divideData.
+ *
  * @param <T> T will be type of data.
  */
 
 public abstract class Input<T> {
-  
+
   public final T data;
-  
+
   public Input(T data) {
     this.data = data;
   }
-  
+
   public abstract ArrayList<Input> divideData(int num);
 }

master-worker-pattern/src/main/java/com/iluwatar/masterworker/Result.java

@@ -24,13 +24,13 @@
 package com.iluwatar.masterworker;
 
 /**
- *The abstract Result class, which contains 1 public field containing result
+ * The abstract Result class, which contains 1 public field containing result data.
- *data.
+ *
  * @param <T> T will be type of data.
  */
 
 public abstract class Result<T> {
-  
+
   public final T data;
 
   public Result(T data) {

master-worker-pattern/src/main/java/com/iluwatar/masterworker/system/ArrayTransposeMasterWorker.java

@@ -27,8 +27,8 @@ import com.iluwatar.masterworker.system.systemmaster.ArrayTransposeMaster;
 import com.iluwatar.masterworker.system.systemmaster.Master;
 
 /**
- *Class ArrayTransposeMasterWorker extends abstract class {@link MasterWorker} and
+ * Class ArrayTransposeMasterWorker extends abstract class {@link MasterWorker} and specifically
- *specifically solves the problem of finding transpose of input array.
+ * solves the problem of finding transpose of input array.
  */
 
 public class ArrayTransposeMasterWorker extends MasterWorker {

master-worker-pattern/src/main/java/com/iluwatar/masterworker/system/MasterWorker.java

@@ -28,7 +28,7 @@ import com.iluwatar.masterworker.Result;
 import com.iluwatar.masterworker.system.systemmaster.Master;
 
 /**
- *The abstract MasterWorker class which contains reference to master.
+ * The abstract MasterWorker class which contains reference to master.
  */
 
 public abstract class MasterWorker {

master-worker-pattern/src/main/java/com/iluwatar/masterworker/system/systemmaster/ArrayTransposeMaster.java

@@ -23,16 +23,15 @@
 
 package com.iluwatar.masterworker.system.systemmaster;
 
-import java.util.ArrayList;
-import java.util.Enumeration;
 import com.iluwatar.masterworker.ArrayResult;
 import com.iluwatar.masterworker.system.systemworkers.ArrayTransposeWorker;
 import com.iluwatar.masterworker.system.systemworkers.Worker;
+import java.util.ArrayList;
+import java.util.Enumeration;
 
 /**
- *Class ArrayTransposeMaster extends abstract class {@link Master} and contains
+ * Class ArrayTransposeMaster extends abstract class {@link Master} and contains definition of
- *definition of aggregateData, which will obtain final result from all
+ * aggregateData, which will obtain final result from all data obtained and for setWorkers.
- *data obtained and for setWorkers.
  */
 
 public class ArrayTransposeMaster extends Master {
@@ -43,26 +42,29 @@ public class ArrayTransposeMaster extends Master {
   @Override
   ArrayList<Worker> setWorkers(int num) {
     ArrayList<Worker> ws = new ArrayList<Worker>(num);
-    for (int i = 0; i < num ; i++) {
+    for (int i = 0; i < num; i++) {
       ws.add(new ArrayTransposeWorker(this, i + 1));
       //i+1 will be id
     }
     return ws;
   }
-  
+
   @Override
   ArrayResult aggregateData() {
-    //number of rows in final result is number of rows in any of obtained results obtained from workers
+    // number of rows in final result is number of rows in any of obtained results from workers
-    int rows = ((ArrayResult) this.getAllResultData().get(this.getAllResultData().keys().nextElement())).data.length;
+    int rows = ((ArrayResult) this.getAllResultData()
-    int columns = 0; //number of columns is sum of number of columns in all results obtained from workers
+        .get(this.getAllResultData().keys().nextElement())).data.length;
-    for (Enumeration<Integer> e = this.getAllResultData().keys(); e.hasMoreElements();) {
+    int columns =
+        0; //number of columns is sum of number of columns in all results obtained from workers
+    for (Enumeration<Integer> e = this.getAllResultData().keys(); e.hasMoreElements(); ) {
       columns += ((ArrayResult) this.getAllResultData().get(e.nextElement())).data[0].length;
     }
     int[][] resultData = new int[rows][columns];
     int columnsDone = 0; //columns aggregated so far
     for (int i = 0; i < this.getExpectedNumResults(); i++) {
       //result obtained from ith worker
-      int[][] work = ((ArrayResult) this.getAllResultData().get(this.getWorkers().get(i).getWorkerId())).data;
+      int[][] work =
+          ((ArrayResult) this.getAllResultData().get(this.getWorkers().get(i).getWorkerId())).data;
       for (int m = 0; m < work.length; m++) {
         //m = row number, n = columns number
         for (int n = 0; n < work[0].length; n++) {
@@ -73,5 +75,5 @@ public class ArrayTransposeMaster extends Master {
     }
     return new ArrayResult(resultData);
   }
-  
+
 }

master-worker-pattern/src/main/java/com/iluwatar/masterworker/system/systemmaster/Master.java

@@ -23,18 +23,17 @@
 
 package com.iluwatar.masterworker.system.systemmaster;
 
-import java.util.ArrayList;
-import java.util.Hashtable;
 import com.iluwatar.masterworker.Input;
 import com.iluwatar.masterworker.Result;
 import com.iluwatar.masterworker.system.systemworkers.Worker;
+import java.util.ArrayList;
+import java.util.Hashtable;
 
 /**
- *The abstract Master class which contains private fields numOfWorkers
+ * The abstract Master class which contains private fields numOfWorkers (number of workers), workers
- *(number of workers), workers (arraylist of workers), expectedNumResults
+ * (arraylist of workers), expectedNumResults (number of divisions of input data, same as expected
- *(number of divisions of input data, same as expected number of results), 
+ * number of results), allResultData (hashtable of results obtained from workers, mapped by their
- *allResultData (hashtable of results obtained from workers, mapped by 
+ * ids) and finalResult (aggregated from allResultData).
- *their ids) and finalResult (aggregated from allResultData).
  */
 
 public abstract class Master {
@@ -43,7 +42,7 @@ public abstract class Master {
   private int expectedNumResults;
   private Hashtable<Integer, Result> allResultData;
   private Result finalResult;
-  
+
   Master(int numOfWorkers) {
     this.numOfWorkers = numOfWorkers;
     this.workers = setWorkers(numOfWorkers);
@@ -51,46 +50,46 @@ public abstract class Master {
     this.allResultData = new Hashtable<Integer, Result>(numOfWorkers);
     this.finalResult = null;
   }
-   
+
   public Result getFinalResult() {
     return this.finalResult;
   }
-   
+
   Hashtable<Integer, Result> getAllResultData() {
     return this.allResultData;
   }
-  
+
   int getExpectedNumResults() {
     return this.expectedNumResults;
   }
-  
+
   ArrayList<Worker> getWorkers() {
     return this.workers;
   }
-  
+
   abstract ArrayList<Worker> setWorkers(int num);
-  
+
   public void doWork(Input input) {
     divideWork(input);
   }
-  
+
   private void divideWork(Input input) {
     ArrayList<Input> dividedInput = input.divideData(numOfWorkers);
     if (dividedInput != null) {
       this.expectedNumResults = dividedInput.size();
-      for (int i = 0; i < this.expectedNumResults; i++) {  
+      for (int i = 0; i < this.expectedNumResults; i++) {
         //ith division given to ith worker in this.workers
         this.workers.get(i).setReceivedData(this, dividedInput.get(i));
         this.workers.get(i).run();
       }
     }
   }
-  
+
   public void receiveData(Result data, Worker w) {
     //check if can receive..if yes:
     collectResult(data, w.getWorkerId());
   }
-  
+
   private void collectResult(Result data, int workerId) {
     this.allResultData.put(workerId, data);
     if (this.allResultData.size() == this.expectedNumResults) {
@@ -98,6 +97,6 @@ public abstract class Master {
       this.finalResult = aggregateData();
     }
   }
-  
+
   abstract Result aggregateData();
 }

master-worker-pattern/src/main/java/com/iluwatar/masterworker/system/systemworkers/ArrayTransposeWorker.java

@@ -28,8 +28,8 @@ import com.iluwatar.masterworker.ArrayResult;
 import com.iluwatar.masterworker.system.systemmaster.Master;
 
 /**
- *Class ArrayTransposeWorker extends abstract class {@link Worker} and defines method
+ * Class ArrayTransposeWorker extends abstract class {@link Worker} and defines method
- *executeOperation(), to be performed on data received from master.
+ * executeOperation(), to be performed on data received from master.
  */
 
 public class ArrayTransposeWorker extends Worker {
@@ -41,12 +41,14 @@ public class ArrayTransposeWorker extends Worker {
   @Override
   ArrayResult executeOperation() {
     //number of rows in result matrix is equal to number of columns in input matrix and vice versa
-    int[][] resultData = new int[((ArrayInput) this.getReceivedData()).data[0].length]
+    ArrayInput arrayInput = (ArrayInput) this.getReceivedData();
-      [((ArrayInput) this.getReceivedData()).data.length];
+    final int rows = arrayInput.data[0].length;
-    for (int i = 0; i < ((ArrayInput) this.getReceivedData()).data.length; i++) {
+    final int cols = arrayInput.data.length;
-      for (int j = 0; j < ((ArrayInput) this.getReceivedData()).data[0].length; j++) {
+    int[][] resultData = new int[rows][cols];
+    for (int i = 0; i < cols; i++) {
+      for (int j = 0; j < rows; j++) {
         //flipping element positions along diagonal
-        resultData[j][i] = ((ArrayInput) this.getReceivedData()).data[i][j]; 
+        resultData[j][i] = arrayInput.data[i][j];
       }
     }
     return new ArrayResult(resultData);

master-worker-pattern/src/main/java/com/iluwatar/masterworker/system/systemworkers/Worker.java

@@ -28,9 +28,8 @@ import com.iluwatar.masterworker.Result;
 import com.iluwatar.masterworker.system.systemmaster.Master;
 
 /**
- *The abstract Worker class which extends Thread class to enable parallel
+ * The abstract Worker class which extends Thread class to enable parallel processing. Contains
- *processing. Contains fields master(holding reference to master), workerId
+ * fields master(holding reference to master), workerId (unique id) and receivedData(from master).
- *(unique id) and receivedData(from master).
  */
 
 public abstract class Worker extends Thread {
@@ -61,7 +60,7 @@ public abstract class Worker extends Thread {
 
   private void sendToMaster(Result data) {
     this.master.receiveData(data, this);
-  } 
+  }
 
   public void run() { //from Thread class
     Result work = executeOperation();

mediator/src/main/java/com/iluwatar/mediator/Action.java

@@ -24,15 +24,15 @@
 package com.iluwatar.mediator;
 
 /**
- * 
  * Action enumeration.
- *
  */
 public enum Action {
 
-  HUNT("hunted a rabbit", "arrives for dinner"), TALE("tells a tale", "comes to listen"), GOLD(
+  HUNT("hunted a rabbit", "arrives for dinner"),
-      "found gold", "takes his share of the gold"), ENEMY("spotted enemies", "runs for cover"), NONE(
+  TALE("tells a tale", "comes to listen"),
-      "", "");
+  GOLD("found gold", "takes his share of the gold"),
+  ENEMY("spotted enemies", "runs for cover"),
+  NONE("", "");
 
   private String title;
   private String description;

mediator/src/main/java/com/iluwatar/mediator/App.java

@@ -24,32 +24,31 @@
 package com.iluwatar.mediator;
 
 /**
- * 
  * The Mediator pattern defines an object that encapsulates how a set of objects interact. This
  * pattern is considered to be a behavioral pattern due to the way it can alter the program's
  * running behavior.
- * <p>
+ *
- * Usually a program is made up of a large number of classes. So the logic and computation is
+ * <p>Usually a program is made up of a large number of classes. So the logic and computation is
  * distributed among these classes. However, as more classes are developed in a program, especially
  * during maintenance and/or refactoring, the problem of communication between these classes may
  * become more complex. This makes the program harder to read and maintain. Furthermore, it can
  * become difficult to change the program, since any change may affect code in several other
  * classes.
- * <p>
+ *
- * With the Mediator pattern, communication between objects is encapsulated with a mediator object.
+ * <p>With the Mediator pattern, communication between objects is encapsulated with a mediator
- * Objects no longer communicate directly with each other, but instead communicate through the
+ * object. Objects no longer communicate directly with each other, but instead communicate through
- * mediator. This reduces the dependencies between communicating objects, thereby lowering the
+ * the mediator. This reduces the dependencies between communicating objects, thereby lowering the
  * coupling.
- * <p>
+ *
- * In this example the mediator encapsulates how a set of objects ({@link PartyMember}) interact.
+ * <p>In this example the mediator encapsulates how a set of objects ({@link PartyMember})
- * Instead of referring to each other directly they use the mediator ({@link Party}) interface.
+ * interact. Instead of referring to each other directly they use the mediator ({@link Party})
- * 
+ * interface.
  */
 public class App {
 
   /**
-   * Program entry point
+   * Program entry point.
-   * 
+   *
    * @param args command line args
    */
   public static void main(String[] args) {

mediator/src/main/java/com/iluwatar/mediator/Hobbit.java

@@ -24,9 +24,7 @@
 package com.iluwatar.mediator;
 
 /**
- * 
  * Hobbit party member.
- *
  */
 public class Hobbit extends PartyMemberBase {
 

mediator/src/main/java/com/iluwatar/mediator/Hunter.java

@@ -24,9 +24,7 @@
 package com.iluwatar.mediator;
 
 /**
- * 
  * Hunter party member.
- *
  */
 public class Hunter extends PartyMemberBase {
 

mediator/src/main/java/com/iluwatar/mediator/Party.java

@@ -24,9 +24,7 @@
 package com.iluwatar.mediator;
 
 /**
- * 
  * Party interface.
- * 
  */
 public interface Party {
 

mediator/src/main/java/com/iluwatar/mediator/PartyImpl.java

@@ -27,9 +27,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 /**
- * 
  * Party implementation.
- *
  */
 public class PartyImpl implements Party {
 

mediator/src/main/java/com/iluwatar/mediator/PartyMember.java

@@ -24,9 +24,7 @@
 package com.iluwatar.mediator;
 
 /**
- * 
  * Interface for party members interacting with {@link Party}.
- * 
  */
 public interface PartyMember {
 

mediator/src/main/java/com/iluwatar/mediator/PartyMemberBase.java

@@ -27,9 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
  * Abstract base class for party members.
- *
  */
 public abstract class PartyMemberBase implements PartyMember {
 

mediator/src/main/java/com/iluwatar/mediator/Rogue.java

@@ -24,9 +24,7 @@
 package com.iluwatar.mediator;
 
 /**
- * 
  * Rogue party member.
- *
  */
 public class Rogue extends PartyMemberBase {
 

mediator/src/main/java/com/iluwatar/mediator/Wizard.java

@@ -24,9 +24,7 @@
 package com.iluwatar.mediator;
 
 /**
- * 
  * Wizard party member.
- *
  */
 public class Wizard extends PartyMemberBase {
 

memento/src/main/java/com/iluwatar/memento/App.java

@@ -23,36 +23,33 @@
 
 package com.iluwatar.memento;
 
+import java.util.Stack;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.Stack;
-
 /**
- * 
  * The Memento pattern is a software design pattern that provides the ability to restore an object
  * to its previous state (undo via rollback).
- * <p>
+ *
- * The Memento pattern is implemented with three objects: the originator, a caretaker and a memento.
+ * <p>The Memento pattern is implemented with three objects: the originator, a caretaker and a
- * The originator is some object that has an internal state. The caretaker is going to do something
+ * memento. The originator is some object that has an internal state. The caretaker is going to do
- * to the originator, but wants to be able to undo the change. The caretaker first asks the
+ * something to the originator, but wants to be able to undo the change. The caretaker first asks
- * originator for a memento object. Then it does whatever operation (or sequence of operations) it
+ * the originator for a memento object. Then it does whatever operation (or sequence of operations)
- * was going to do. To roll back to the state before the operations, it returns the memento object
+ * it was going to do. To roll back to the state before the operations, it returns the memento
- * to the originator. The memento object itself is an opaque object (one which the caretaker cannot,
+ * object to the originator. The memento object itself is an opaque object (one which the caretaker
- * or should not, change). When using this pattern, care should be taken if the originator may
+ * cannot, or should not, change). When using this pattern, care should be taken if the originator
- * change other objects or resources - the memento pattern operates on a single object.
+ * may change other objects or resources - the memento pattern operates on a single object.
- * <p>
+ *
- * In this example the object ({@link Star}) gives out a "memento" ({@link StarMemento}) that
+ * <p>In this example the object ({@link Star}) gives out a "memento" ({@link StarMemento}) that
  * contains the state of the object. Later on the memento can be set back to the object restoring
  * the state.
- * 
  */
 public class App {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
 
   /**
-   * Program entry point
+   * Program entry point.
    */
   public static void main(String[] args) {
     Stack<StarMemento> states = new Stack<>();

memento/src/main/java/com/iluwatar/memento/Star.java

@@ -24,9 +24,7 @@
 package com.iluwatar.memento;
 
 /**
- * 
  * Star uses "mementos" to store and restore state.
- * 
  */
 public class Star {
 
@@ -35,7 +33,7 @@ public class Star {
   private int massTons;
 
   /**
-   * Constructor
+   * Constructor.
    */
   public Star(StarType startType, int startAge, int startMass) {
     this.type = startType;
@@ -44,7 +42,7 @@ public class Star {
   }
 
   /**
-   * Makes time pass for the star
+   * Makes time pass for the star.
    */
   public void timePasses() {
     ageYears *= 2;
@@ -96,9 +94,7 @@ public class Star {
   }
 
   /**
-   * 
+   * StarMemento implementation.
-   * StarMemento implementation
-   * 
    */
   private static class StarMementoInternal implements StarMemento {
 

memento/src/main/java/com/iluwatar/memento/StarMemento.java

@@ -24,9 +24,7 @@
 package com.iluwatar.memento;
 
 /**
- * 
  * External interface to memento.
- * 
  */
 public interface StarMemento {
 

memento/src/main/java/com/iluwatar/memento/StarType.java

@@ -24,9 +24,7 @@
 package com.iluwatar.memento;
 
 /**
- * 
+ * StarType enumeration.
- * StarType enumeration
- *
  */
 public enum StarType {
 

model-view-controller/src/main/java/com/iluwatar/model/view/controller/App.java

@@ -24,27 +24,25 @@
 package com.iluwatar.model.view.controller;
 
 /**
- * 
  * Model-View-Controller is a pattern for implementing user interfaces. It divides the application
  * into three interconnected parts namely the model, the view and the controller.
- * <p>
- * The central component of MVC, the model, captures the behavior of the application in terms of its
- * problem domain, independent of the user interface. The model directly manages the data, logic and
- * rules of the application. A view can be any output representation of information, such as a chart
- * or a diagram The third part, the controller, accepts input and converts it to commands for the
- * model or view.
- * <p>
- * In this example we have a giant ({@link GiantModel}) with statuses for health, fatigue and
- * nourishment. {@link GiantView} can display the giant with its current status.
- * {@link GiantController} receives input affecting the model and delegates redrawing the giant to
- * the view.
  *
+ * <p>The central component of MVC, the model, captures the behavior of the application in terms of
+ * its problem domain, independent of the user interface. The model directly manages the data, logic
+ * and rules of the application. A view can be any output representation of information, such as a
+ * chart or a diagram The third part, the controller, accepts input and converts it to commands for
+ * the model or view.
+ *
+ * <p>In this example we have a giant ({@link GiantModel}) with statuses for health, fatigue and
+ * nourishment. {@link GiantView} can display the giant with its current status. {@link
+ * GiantController} receives input affecting the model and delegates redrawing the giant to the
+ * view.
  */
 public class App {
 
   /**
-   * Program entry point
+   * Program entry point.
-   * 
+   *
    * @param args command line args
    */
   public static void main(String[] args) {

model-view-controller/src/main/java/com/iluwatar/model/view/controller/Fatigue.java

@@ -24,9 +24,7 @@
 package com.iluwatar.model.view.controller;
 
 /**
- * 
+ * Fatigue enumeration.
- * Fatigue enumeration
- *
  */
 public enum Fatigue {
 

model-view-controller/src/main/java/com/iluwatar/model/view/controller/GiantController.java

@@ -24,9 +24,7 @@
 package com.iluwatar.model.view.controller;
 
 /**
- * 
  * GiantController can update the giant data and redraw it using the view.
- *
  */
 public class GiantController {
 

model-view-controller/src/main/java/com/iluwatar/model/view/controller/GiantModel.java

@@ -24,9 +24,7 @@
 package com.iluwatar.model.view.controller;
 
 /**
- * 
+ * GiantModel contains the giant data.
- * GiantModel contains the giant data
- *
  */
 public class GiantModel {
 

model-view-controller/src/main/java/com/iluwatar/model/view/controller/GiantView.java

@@ -27,9 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
+ * GiantView displays the giant.
- * GiantView displays the giant
- *
  */
 public class GiantView {
 

model-view-controller/src/main/java/com/iluwatar/model/view/controller/Health.java

@@ -24,9 +24,7 @@
 package com.iluwatar.model.view.controller;
 
 /**
- * 
+ * Health enumeration.
- * Health enumeration
- *
  */
 public enum Health {
 

model-view-controller/src/main/java/com/iluwatar/model/view/controller/Nourishment.java

@@ -24,9 +24,7 @@
 package com.iluwatar.model.view.controller;
 
 /**
- * 
+ * Nourishment enumeration.
- * Nourishment enumeration
- *
  */
 public enum Nourishment {
 

model-view-presenter/src/main/java/com/iluwatar/model/view/presenter/App.java

@@ -24,31 +24,29 @@
 package com.iluwatar.model.view.presenter;
 
 /**
- * 
+ * The Model-View-Presenter(MVP) architectural pattern, helps us achieve what is called "The
- * The Model-View-Presenter(MVP) architectural pattern, helps us achieve what is called
+ * separation of concerns" principle. This is accomplished by separating the application's logic
- * "The separation of concerns" principle. This is accomplished by separating the application's
+ * (Model), GUIs (View), and finally the way that the user's actions update the application's logic
- * logic (Model), GUIs (View), and finally the way that the user's actions update the application's
+ * (Presenter).
- * logic (Presenter).
+ *
- * <p>
+ * <p>In the following example, The {@link FileLoader} class represents the app's logic, the {@link
- * In the following example, The {@link FileLoader} class represents the app's logic, the
+ * FileSelectorJFrame} is the GUI and the {@link FileSelectorPresenter} is responsible to respond to
- * {@link FileSelectorJFrame} is the GUI and the {@link FileSelectorPresenter} is responsible to
+ * users' actions.
- * respond to users' actions.
+ *
- * <p>
+ * <p>Finally, please notice the wiring between the Presenter and the View and between the
- * Finally, please notice the wiring between the Presenter and the View and between the Presenter
+ * Presenter and the Model.
- * and the Model.
- * 
  */
 public class App {
 
   /**
-   * Program entry point
+   * Program entry point.
-   * 
+   *
    * @param args command line args
    */
   public static void main(String[] args) {
     FileLoader loader = new FileLoader();
-    FileSelectorJFrame jFrame = new FileSelectorJFrame();
+    FileSelectorJFrame frame = new FileSelectorJFrame();
-    FileSelectorPresenter presenter = new FileSelectorPresenter(jFrame);
+    FileSelectorPresenter presenter = new FileSelectorPresenter(frame);
     presenter.setLoader(loader);
     presenter.start();
   }

model-view-presenter/src/main/java/com/iluwatar/model/view/presenter/FileLoader.java

@@ -27,23 +27,22 @@ import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileReader;
 import java.io.Serializable;
-
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
  * Every instance of this class represents the Model component in the Model-View-Presenter
  * architectural pattern.
- * <p>
+ *
- * It is responsible for reading and loading the contents of a given file.
+ * <p>It is responsible for reading and loading the contents of a given file.
  */
 public class FileLoader implements Serializable {
 
   /**
-   * Generated serial version UID
+   * Generated serial version UID.
    */
   private static final long serialVersionUID = -4745803872902019069L;
-  
+
   private static final Logger LOGGER = LoggerFactory.getLogger(FileLoader.class);
 
   /**
@@ -81,7 +80,7 @@ public class FileLoader implements Serializable {
 
   /**
    * Sets the path of the file to be loaded, to the given value.
-   * 
+   *
    * @param fileName The path of the file to be loaded.
    */
   public void setFileName(String fileName) {
@@ -89,6 +88,8 @@ public class FileLoader implements Serializable {
   }
 
   /**
+   * Gets the path of the file to be loaded.
+   *
    * @return fileName The path of the file to be loaded.
    */
   public String getFileName() {
@@ -96,6 +97,8 @@ public class FileLoader implements Serializable {
   }
 
   /**
+   * Returns true if the given file exists.
+   *
    * @return True, if the file given exists, false otherwise.
    */
   public boolean fileExists() {
@@ -103,6 +106,8 @@ public class FileLoader implements Serializable {
   }
 
   /**
+   * Returns true if the given file is loaded.
+   *
    * @return True, if the file is loaded, false otherwise.
    */
   public boolean isLoaded() {

model-view-presenter/src/main/java/com/iluwatar/model/view/presenter/FileSelectorJFrame.java

@@ -26,7 +26,6 @@ package com.iluwatar.model.view.presenter;
 import java.awt.Color;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
-
 import javax.swing.JButton;
 import javax.swing.JFrame;
 import javax.swing.JLabel;
@@ -82,7 +81,7 @@ public class FileSelectorJFrame extends JFrame implements FileSelectorView, Acti
   private JPanel panel;
 
   /**
-   * The Presenter component that the frame will interact with
+   * The Presenter component that the frame will interact with.
    */
   private FileSelectorPresenter presenter;
 

model-view-presenter/src/main/java/com/iluwatar/model/view/presenter/FileSelectorPresenter.java

@@ -28,13 +28,13 @@ import java.io.Serializable;
 /**
  * Every instance of this class represents the Presenter component in the Model-View-Presenter
  * architectural pattern.
- * <p>
+ *
- * It is responsible for reacting to the user's actions and update the View component.
+ * <p>It is responsible for reacting to the user's actions and update the View component.
  */
 public class FileSelectorPresenter implements Serializable {
 
   /**
-   * Generated serial version UID
+   * Generated serial version UID.
    */
   private static final long serialVersionUID = 1210314339075855074L;
 
@@ -49,8 +49,8 @@ public class FileSelectorPresenter implements Serializable {
   private FileLoader loader;
 
   /**
-   * Constructor
+   * Constructor.
-   * 
+   *
    * @param view The view component that the presenter will interact with.
    */
   public FileSelectorPresenter(FileSelectorView view) {
@@ -59,7 +59,7 @@ public class FileSelectorPresenter implements Serializable {
 
   /**
    * Sets the {@link FileLoader} object, to the value given as parameter.
-   * 
+   *
    * @param loader The new {@link FileLoader} object(the Model component).
    */
   public void setLoader(FileLoader loader) {
@@ -82,7 +82,7 @@ public class FileSelectorPresenter implements Serializable {
   }
 
   /**
-   * Ok button handler
+   * Ok button handler.
    */
   public void confirmed() {
     if (loader.getFileName() == null || loader.getFileName().equals("")) {

model-view-presenter/src/main/java/com/iluwatar/model/view/presenter/FileSelectorStub.java

@@ -26,12 +26,12 @@ package com.iluwatar.model.view.presenter;
 /**
  * Every instance of this class represents the Stub component in the Model-View-Presenter
  * architectural pattern.
- * <p>
+ *
- * The stub implements the View interface and it is useful when we want the test the reaction to
+ * <p>The stub implements the View interface and it is useful when we want the test the reaction to
  * user events, such as mouse clicks.
- * <p>
+ *
- * Since we can not test the GUI directly, the MVP pattern provides this functionality through the
+ * <p>Since we can not test the GUI directly, the MVP pattern provides this functionality through
- * View's dummy implementation, the Stub.
+ * the View's dummy implementation, the Stub.
  */
 public class FileSelectorStub implements FileSelectorView {
 
@@ -61,7 +61,7 @@ public class FileSelectorStub implements FileSelectorView {
   private boolean dataDisplayed;
 
   /**
-   * Constructor
+   * Constructor.
    */
   public FileSelectorStub() {
     this.opened = false;
@@ -124,6 +124,8 @@ public class FileSelectorStub implements FileSelectorView {
   }
 
   /**
+   * Returns true, if the data were displayed.
+   *
    * @return True if the data where displayed, false otherwise.
    */
   public boolean dataDisplayed() {

model-view-presenter/src/main/java/com/iluwatar/model/view/presenter/FileSelectorView.java

@@ -42,44 +42,50 @@ public interface FileSelectorView extends Serializable {
   void close();
 
   /**
+   * Returns true if view is opened.
+   *
    * @return True, if the view is opened, false otherwise.
    */
   boolean isOpened();
 
   /**
    * Sets the presenter component, to the one given as parameter.
-   * 
+   *
    * @param presenter The new presenter component.
    */
   void setPresenter(FileSelectorPresenter presenter);
 
   /**
+   * Gets presenter component.
+   *
    * @return The presenter Component.
    */
   FileSelectorPresenter getPresenter();
 
   /**
    * Sets the file's name, to the value given as parameter.
-   * 
+   *
    * @param name The new name of the file.
    */
   void setFileName(String name);
 
   /**
+   * Gets the name of file.
+   *
    * @return The name of the file.
    */
   String getFileName();
 
   /**
    * Displays a message to the users.
-   * 
+   *
    * @param message The message to be displayed.
    */
   void showMessage(String message);
 
   /**
    * Displays the data to the view.
-   * 
+   *
    * @param data The data to be written.
    */
   void displayData(String data);

module/src/main/java/com/iluwatar/module/App.java

@@ -31,10 +31,9 @@ import java.io.FileNotFoundException;
  * An object that applies this pattern can provide the equivalent of a namespace, providing the
  * initialization and finalization process of a static class or a class with static members with
  * cleaner, more concise syntax and semantics.
- * <p>
+ *
- * The below example demonstrates a use case for testing two different modules: File Logger and
+ * <p>The below example demonstrates a use case for testing two different modules: File Logger and
  * Console Logger
- * 
  */
 public class App {
 
@@ -42,10 +41,10 @@ public class App {
   public static ConsoleLoggerModule consoleLoggerModule;
 
   /**
-   * Following method performs the initialization
+   * Following method performs the initialization.
-   * 
+   *
    * @throws FileNotFoundException if program is not able to find log files (output.txt and
-   *         error.txt)
+   *                               error.txt)
    */
   public static void prepare() throws FileNotFoundException {
 
@@ -55,7 +54,7 @@ public class App {
   }
 
   /**
-   * Following method performs the finalization
+   * Following method performs the finalization.
    */
   public static void unprepare() {
 
@@ -65,8 +64,8 @@ public class App {
   }
 
   /**
-   * Following method is main executor
+   * Following method is main executor.
-   * 
+   *
    * @param args for providing default program arguments
    */
   public static void execute(final String... args) {
@@ -82,10 +81,10 @@ public class App {
 
   /**
    * Program entry point.
-   * 
+   *
    * @param args command line args.
    * @throws FileNotFoundException if program is not able to find log files (output.txt and
-   *         error.txt)
+   *                               error.txt)
    */
   public static void main(final String... args) throws FileNotFoundException {
     prepare();

module/src/main/java/com/iluwatar/module/ConsoleLoggerModule.java

@@ -23,16 +23,15 @@
 
 package com.iluwatar.module;
 
+import java.io.PrintStream;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.PrintStream;
-
 /**
- * The ConsoleLoggerModule is responsible for showing logs on System Console
+ * The ConsoleLoggerModule is responsible for showing logs on System Console.
- * <p>
+ *
- * The below example demonstrates a Console logger module, which can print simple and error messages
+ * <p>The below example demonstrates a Console logger module, which can print simple and error
- * in two designated formats
+ * messages in two designated formats
  */
 public final class ConsoleLoggerModule {
 
@@ -43,11 +42,12 @@ public final class ConsoleLoggerModule {
   public PrintStream output = null;
   public PrintStream error = null;
 
-  private ConsoleLoggerModule() {}
+  private ConsoleLoggerModule() {
+  }
 
   /**
-   * Static method to get single instance of class
+   * Static method to get single instance of class.
-   * 
+   *
    * @return singleton instance of ConsoleLoggerModule
    */
   public static ConsoleLoggerModule getSingleton() {
@@ -60,7 +60,7 @@ public final class ConsoleLoggerModule {
   }
 
   /**
-   * Following method performs the initialization
+   * Following method performs the initialization.
    */
   public ConsoleLoggerModule prepare() {
 
@@ -73,7 +73,7 @@ public final class ConsoleLoggerModule {
   }
 
   /**
-   * Following method performs the finalization
+   * Following method performs the finalization.
    */
   public void unprepare() {
 
@@ -93,8 +93,8 @@ public final class ConsoleLoggerModule {
   }
 
   /**
-   * Used to print a message
+   * Used to print a message.
-   * 
+   *
    * @param value will be printed on console
    */
   public void printString(final String value) {
@@ -102,8 +102,8 @@ public final class ConsoleLoggerModule {
   }
 
   /**
-   * Used to print a error message
+   * Used to print a error message.
-   * 
+   *
    * @param value will be printed on error console
    */
   public void printErrorString(final String value) {

module/src/main/java/com/iluwatar/module/FileLoggerModule.java

@@ -23,18 +23,17 @@
 
 package com.iluwatar.module;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.PrintStream;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
- * The FileLoggerModule is responsible for showing logs on File System
+ * The FileLoggerModule is responsible for showing logs on File System.
- * <p>
+ *
- * The below example demonstrates a File logger module, which can print simple and error messages in
+ * <p>The below example demonstrates a File logger module, which can print simple and error
- * two designated files
+ * messages in two designated files
  */
 public final class FileLoggerModule {
 
@@ -48,11 +47,12 @@ public final class FileLoggerModule {
   public PrintStream output = null;
   public PrintStream error = null;
 
-  private FileLoggerModule() {}
+  private FileLoggerModule() {
+  }
 
   /**
-   * Static method to get single instance of class
+   * Static method to get single instance of class.
-   * 
+   *
    * @return singleton instance of FileLoggerModule
    */
   public static FileLoggerModule getSingleton() {
@@ -65,10 +65,10 @@ public final class FileLoggerModule {
   }
 
   /**
-   * Following method performs the initialization
+   * Following method performs the initialization.
-   * 
+   *
    * @throws FileNotFoundException if program is not able to find log files (output.txt and
-   *         error.txt)
+   *                               error.txt)
    */
   public FileLoggerModule prepare() throws FileNotFoundException {
 
@@ -81,7 +81,7 @@ public final class FileLoggerModule {
   }
 
   /**
-   * Following method performs the finalization
+   * Following method performs the finalization.
    */
   public void unprepare() {
 
@@ -101,8 +101,8 @@ public final class FileLoggerModule {
   }
 
   /**
-   * Used to print a message
+   * Used to print a message.
-   * 
+   *
    * @param value will be printed in file
    */
   public void printString(final String value) {
@@ -110,8 +110,8 @@ public final class FileLoggerModule {
   }
 
   /**
-   * Used to print a error message
+   * Used to print a error message.
-   * 
+   *
    * @param value will be printed on error file
    */
   public void printErrorString(final String value) {

monad/src/main/java/com/iluwatar/monad/App.java

@@ -23,26 +23,27 @@
 
 package com.iluwatar.monad;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.util.Objects;
 import java.util.function.Function;
 import java.util.function.Predicate;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
- * The Monad pattern defines a monad structure, that enables chaining operations
+ * The Monad pattern defines a monad structure, that enables chaining operations in pipelines and
- * in pipelines and processing data step by step.
+ * processing data step by step. Formally, monad consists of a type constructor M and two
- * Formally, monad consists of a type constructor M and two operations:
+ * operations:
  * <br>bind - that takes monadic object and a function from plain object to the
  * monadic value and returns monadic value.
  * <br>return - that takes plain type object and returns this object wrapped in a monadic value.
- * <p>
+ *
- * In the given example, the Monad pattern is represented as a {@link Validator} that takes an instance
+ * <p>In the given example, the Monad pattern is represented as a {@link Validator} that takes an
- * of a plain object with {@link Validator#of(Object)}
+ * instance of a plain object with {@link Validator#of(Object)} and validates it {@link
- * and validates it {@link Validator#validate(Function, Predicate, String)} against given predicates.
+ * Validator#validate(Function, Predicate, String)} against given predicates.
- * <p>As a validation result {@link Validator#get()} it either returns valid object {@link Validator#t}
+ *
- * or throws a list of exceptions {@link Validator#exceptions} collected during validation.
+ * <p>As a validation result {@link Validator#get()} it either returns valid object {@link
+ * Validator#t} or throws a list of exceptions {@link Validator#exceptions} collected during
+ * validation.
  */
 public class App {
 
@@ -58,6 +59,7 @@ public class App {
     LOGGER.info(Validator.of(user).validate(User::getName, Objects::nonNull, "name is null")
         .validate(User::getName, name -> !name.isEmpty(), "name is empty")
         .validate(User::getEmail, email -> !email.contains("@"), "email doesn't containt '@'")
-        .validate(User::getAge, age -> age > 20 && age < 30, "age isn't between...").get().toString());
+        .validate(User::getAge, age -> age > 20 && age < 30, "age isn't between...").get()
+        .toString());
   }
 }

monad/src/main/java/com/iluwatar/monad/Sex.java

@@ -24,7 +24,7 @@
 package com.iluwatar.monad;
 
 /**
- * Enumeration of Types of Sex
+ * Enumeration of Types of Sex.
  */
 public enum Sex {
   MALE, FEMALE

monad/src/main/java/com/iluwatar/monad/User.java

@@ -24,7 +24,7 @@
 package com.iluwatar.monad;
 
 /**
- * User Definition
+ * User Definition.
  */
 public class User {
 
@@ -34,6 +34,8 @@ public class User {
   private String email;
 
   /**
+   * Constructor.
+   *
    * @param name  - name
    * @param age   - age
    * @param sex   - sex

monad/src/main/java/com/iluwatar/monad/Validator.java

@@ -30,18 +30,18 @@ import java.util.function.Function;
 import java.util.function.Predicate;
 
 /**
- * Class representing Monad design pattern. Monad is a way of chaining operations on the
+ * Class representing Monad design pattern. Monad is a way of chaining operations on the given
- * given object together step by step. In Validator each step results in either success or
+ * object together step by step. In Validator each step results in either success or failure
- * failure indicator, giving a way of receiving each of them easily and finally getting
+ * indicator, giving a way of receiving each of them easily and finally getting validated object or
- * validated object or list of exceptions.
+ * list of exceptions.
  *
  * @param <T> Placeholder for an object.
  */
 public class Validator<T> {
   /**
-   * Object that is validated
+   * Object that is validated.
    */
-  private final T t;
+  private final T obj;
 
   /**
    * List of exception thrown during validation.
@@ -50,14 +50,15 @@ public class Validator<T> {
 
   /**
    * Creates a monadic value of given object.
-   * @param t object to be validated
+   *
+   * @param obj object to be validated
    */
-  private Validator(T t) {
+  private Validator(T obj) {
-    this.t = t;
+    this.obj = obj;
   }
 
   /**
-   * Creates validator against given object
+   * Creates validator against given object.
    *
    * @param t   object to be validated
    * @param <T> object's type
@@ -68,25 +69,27 @@ public class Validator<T> {
   }
 
   /**
-   * @param validation one argument boolean-valued function that
+   * Checks if the validation is successful.
-   *                   represents one step of validation. Adds exception to main validation exception
+   *
-   *                   list when single step validation ends with failure.
+   * @param validation one argument boolean-valued function that represents one step of validation.
+   *                   Adds exception to main validation exception list when single step validation
+   *                   ends with failure.
    * @param message    error message when object is invalid
    * @return this
    */
   public Validator<T> validate(Predicate<T> validation, String message) {
-    if (!validation.test(t)) {
+    if (!validation.test(obj)) {
       exceptions.add(new IllegalStateException(message));
     }
     return this;
   }
 
   /**
-   * Extension for the {@link Validator#validate(Function, Predicate, String)} method,
+   * Extension for the {@link Validator#validate(Function, Predicate, String)} method, dedicated for
-   * dedicated for objects, that need to be projected before requested validation.
+   * objects, that need to be projected before requested validation.
    *
-   * @param projection function that gets an objects, and returns projection representing
+   * @param projection function that gets an objects, and returns projection representing element to
-   *                   element to be validated.
+   *                   be validated.
    * @param validation see {@link Validator#validate(Function, Predicate, String)}
    * @param message    see {@link Validator#validate(Function, Predicate, String)}
    * @param <U>        see {@link Validator#validate(Function, Predicate, String)}
@@ -105,7 +108,7 @@ public class Validator<T> {
    */
   public T get() throws IllegalStateException {
     if (exceptions.isEmpty()) {
-      return t;
+      return obj;
     }
     IllegalStateException e = new IllegalStateException();
     exceptions.forEach(e::addSuppressed);

monostate/src/main/java/com/iluwatar/monostate/App.java

@@ -24,28 +24,22 @@
 package com.iluwatar.monostate;
 
 
-
 /**
- * 
  * The MonoState pattern ensures that all instances of the class will have the same state. This can
  * be used a direct replacement of the Singleton pattern.
- * 
+ *
- * <p>
+ * <p>In the following example, The {@link LoadBalancer} class represents the app's logic. It
- * In the following example, The {@link LoadBalancer} class represents the app's logic. It contains
+ * contains a series of Servers, which can handle requests of type {@link Request}. Two instances of
- * a series of Servers, which can handle requests of type {@link Request}. Two instances of
  * LoadBalacer are created. When a request is made to a server via the first LoadBalancer the state
  * change in the first load balancer affects the second. So if the first LoadBalancer selects the
  * Server 1, the second LoadBalancer on a new request will select the Second server. If a third
  * LoadBalancer is created and a new request is made to it, then it will select the third server as
  * the second load balancer has already selected the second server.
- * <p>
- * .
- * 
  */
 public class App {
   /**
-   * Program entry point
+   * Program entry point.
-   * 
+   *
    * @param args command line args
    */
   public static void main(String[] args) {

monostate/src/main/java/com/iluwatar/monostate/LoadBalancer.java

@@ -31,7 +31,6 @@ import java.util.List;
  * receiving a new Request, it delegates the call to the servers in a Round Robin Fashion. Since all
  * instances of the class share the same state, all instances will delegate to the same server on
  * receiving a new Request.
- * 
  */
 
 public class LoadBalancer {
@@ -40,13 +39,13 @@ public class LoadBalancer {
 
   static {
     int id = 0;
-    for (int port : new int[] {8080, 8081, 8082, 8083, 8084}) {
+    for (int port : new int[]{8080, 8081, 8082, 8083, 8084}) {
       SERVERS.add(new Server("localhost", port, ++id));
     }
   }
 
   /**
-   * Add new server
+   * Add new server.
    */
   public final void addServer(Server server) {
     synchronized (SERVERS) {
@@ -64,7 +63,7 @@ public class LoadBalancer {
   }
 
   /**
-   * Handle request
+   * Handle request.
    */
   public synchronized void serverRequest(Request request) {
     if (lastServedId >= SERVERS.size()) {
@@ -73,5 +72,5 @@ public class LoadBalancer {
     Server server = SERVERS.get(lastServedId++);
     server.serve(request);
   }
-  
+
 }

monostate/src/main/java/com/iluwatar/monostate/Request.java

@@ -24,9 +24,7 @@
 package com.iluwatar.monostate;
 
 /**
- * 
  * The Request class. A {@link Server} can handle an instance of a Request.
- * 
  */
 
 public class Request {

monostate/src/main/java/com/iluwatar/monostate/Server.java

@@ -27,10 +27,8 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
  * The Server class. Each Server sits behind a LoadBalancer which delegates the call to the servers
  * in a simplistic Round Robin fashion.
- *
  */
 public class Server {
 
@@ -41,7 +39,7 @@ public class Server {
   public final int id;
 
   /**
-   * Constructor
+   * Constructor.
    */
   public Server(String host, int port, int id) {
     this.host = host;
@@ -59,6 +57,6 @@ public class Server {
 
   public void serve(Request request) {
     LOGGER.info("Server ID {} associated to host : {} and port {}. Processed request with value {}",
-            id, host, port, request.value);
+        id, host, port, request.value);
   }
 }

multiton/src/main/java/com/iluwatar/multiton/App.java

@@ -27,26 +27,24 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
  * Whereas Singleton design pattern introduces single globally accessible object the Multiton
  * pattern defines many globally accessible objects. The client asks for the correct instance from
  * the Multiton by passing an enumeration as parameter.
- * <p>
- * There is more than one way to implement the multiton design pattern. In the first example
- * {@link Nazgul} is the Multiton and we can ask single {@link Nazgul} from it using {@link NazgulName}.
- * The {@link Nazgul}s are statically initialized and stored in concurrent hash map.
- * <p>
- * In the enum implementation {@link NazgulEnum} is the multiton. It is static and mutable because
- * of the way java supports enums.
  *
+ * <p>There is more than one way to implement the multiton design pattern. In the first example
+ * {@link Nazgul} is the Multiton and we can ask single {@link Nazgul} from it using {@link
+ * NazgulName}. The {@link Nazgul}s are statically initialized and stored in concurrent hash map.
+ *
+ * <p>In the enum implementation {@link NazgulEnum} is the multiton. It is static and mutable
+ * because of the way java supports enums.
  */
 public class App {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
 
   /**
-   * Program entry point
+   * Program entry point.
-   * 
+   *
    * @param args command line args
    */
   public static void main(String[] args) {
@@ -60,7 +58,7 @@ public class App {
     LOGGER.info("ADUNAPHEL={}", Nazgul.getInstance(NazgulName.ADUNAPHEL));
     LOGGER.info("REN={}", Nazgul.getInstance(NazgulName.REN));
     LOGGER.info("UVATHA={}", Nazgul.getInstance(NazgulName.UVATHA));
-    
+
     // enum multiton
     LOGGER.info("KHAMUL={}", NazgulEnum.KHAMUL);
     LOGGER.info("MURAZOR={}", NazgulEnum.MURAZOR);

multiton/src/main/java/com/iluwatar/multiton/Nazgul.java

@@ -27,9 +27,7 @@ import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
- * 
  * Nazgul is a Multiton class. Nazgul instances can be queried using {@link #getInstance} method.
- *
  */
 public final class Nazgul {
 

multiton/src/main/java/com/iluwatar/multiton/NazgulEnum.java

@@ -24,11 +24,10 @@
 package com.iluwatar.multiton;
 
 /**
- * enum based multiton implementation
+ * enum based multiton implementation.
- *
  */
 public enum NazgulEnum {
-  
+
   KHAMUL, MURAZOR, DWAR, JI_INDUR, AKHORAHIL, HOARMURATH, ADUNAPHEL, REN, UVATHA;
 
 }

multiton/src/main/java/com/iluwatar/multiton/NazgulName.java

@@ -24,9 +24,7 @@
 package com.iluwatar.multiton;
 
 /**
- * 
  * Each Nazgul has different {@link NazgulName}.
- *
  */
 public enum NazgulName {
 

mute-idiom/src/main/java/com/iluwatar/mute/App.java

@@ -23,19 +23,17 @@
 
 package com.iluwatar.mute;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.sql.SQLException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
- * Mute pattern is utilized when we need to suppress an exception due to an API flaw or in 
+ * Mute pattern is utilized when we need to suppress an exception due to an API flaw or in situation
- * situation when all we can do to handle the exception is to log it. 
+ * when all we can do to handle the exception is to log it. This pattern should not be used
- * This pattern should not be used everywhere. It is very important to logically handle the 
+ * everywhere. It is very important to logically handle the exceptions in a system, but some
- * exceptions in a system, but some situations like the ones described above require this pattern, 
+ * situations like the ones described above require this pattern, so that we don't need to repeat
- * so that we don't need to repeat 
  * <pre>
  * <code>
  *   try {
@@ -45,7 +43,6 @@ import java.sql.SQLException;
  *   }
  * </code>
  * </pre> every time we need to ignore an exception.
- * 
  */
 public class App {
 
@@ -53,7 +50,7 @@ public class App {
 
   /**
    * Program entry point.
-   * 
+   *
    * @param args command line args.
    * @throws Exception if any exception occurs
    */
@@ -65,7 +62,7 @@ public class App {
   }
 
   /*
-   * Typically used when the API declares some exception but cannot do so. Usually a 
+   * Typically used when the API declares some exception but cannot do so. Usually a
    * signature mistake.In this example out is not supposed to throw exception as it is a
    * ByteArrayOutputStream. So we utilize mute, which will throw AssertionError if unexpected
    * exception occurs.
@@ -98,7 +95,7 @@ public class App {
 
   private static Resource acquireResource() throws SQLException {
     return new Resource() {
-      
+
       @Override
       public void close() throws IOException {
         throw new IOException("Error in closing resource: " + this);

mute-idiom/src/main/java/com/iluwatar/mute/CheckedRunnable.java

@@ -25,12 +25,12 @@ package com.iluwatar.mute;
 
 /**
  * A runnable which may throw exception on execution.
- *
  */
 @FunctionalInterface
 public interface CheckedRunnable {
   /**
    * Same as {@link Runnable#run()} with a possibility of exception in execution.
+   *
    * @throws Exception if any exception occurs.
    */
   void run() throws Exception;

mute-idiom/src/main/java/com/iluwatar/mute/Mute.java

@@ -30,17 +30,18 @@ import java.io.IOException;
  * A utility class that allows you to utilize mute idiom.
  */
 public final class Mute {
-  
+
   // The constructor is never meant to be called.
-  private Mute() {}
+  private Mute() {
+  }
 
   /**
-   * Executes the <code>runnable</code> and throws the exception occurred within a {@link AssertionError}.
+   * Executes the <code>runnable</code> and throws the exception occurred within a {@link
-   * This method should be utilized to mute the operations that are guaranteed not to throw an exception.
+   * AssertionError}. This method should be utilized to mute the operations that are guaranteed not
-   * For instance {@link ByteArrayOutputStream#write(byte[])} declares in it's signature that it can throw
+   * to throw an exception. For instance {@link ByteArrayOutputStream#write(byte[])} declares in
-   * an {@link IOException}, but in reality it cannot. This is because the bulk write method is not overridden
+   * it's signature that it can throw an {@link IOException}, but in reality it cannot. This is
-   * in {@link ByteArrayOutputStream}.
+   * because the bulk write method is not overridden in {@link ByteArrayOutputStream}.
-   * 
+   *
    * @param runnable a runnable that should never throw an exception on execution.
    */
   public static void mute(CheckedRunnable runnable) {
@@ -52,11 +53,11 @@ public final class Mute {
   }
 
   /**
-   * Executes the <code>runnable</code> and logs the exception occurred on {@link System#err}.
+   * Executes the <code>runnable</code> and logs the exception occurred on {@link System#err}. This
-   * This method should be utilized to mute the operations about which most you can do is log.
+   * method should be utilized to mute the operations about which most you can do is log. For
-   * For instance while closing a connection to database, or cleaning up a resource, 
+   * instance while closing a connection to database, or cleaning up a resource, all you can do is
-   * all you can do is log the exception occurred.
+   * log the exception occurred.
-   * 
+   *
    * @param runnable a runnable that may throw an exception on execution.
    */
   public static void loggedMute(CheckedRunnable runnable) {

mute-idiom/src/main/java/com/iluwatar/mute/Resource.java

@@ -26,9 +26,8 @@ package com.iluwatar.mute;
 import java.io.Closeable;
 
 /**
- * Represents any resource that the application might acquire and that must be closed
+ * Represents any resource that the application might acquire and that must be closed after it is
- * after it is utilized. Example of such resources can be a database connection, open
+ * utilized. Example of such resources can be a database connection, open files, sockets.
- * files, sockets. 
  */
 public interface Resource extends Closeable {
 

mutex/src/main/java/com/iluwatar/mutex/App.java

@@ -25,19 +25,17 @@ package com.iluwatar.mutex;
 
 /**
  * A Mutex prevents multiple threads from accessing a resource simultaneously.
- * <p>
+ *
- * In this example we have two thieves who are taking beans from a jar.
+ * <p>In this example we have two thieves who are taking beans from a jar. Only one thief can take
- * Only one thief can take a bean at a time. This is ensured by a Mutex lock
+ * a bean at a time. This is ensured by a Mutex lock which must be acquired in order to access the
- * which must be acquired in order to access the jar. Each thief attempts to
+ * jar. Each thief attempts to acquire the lock, take a bean and then release the lock. If the lock
- * acquire the lock, take a bean and then release the lock. If the lock has 
+ * has already been acquired, the thief will be prevented from continuing (blocked) until the lock
- * already been acquired, the thief will be prevented from continuing (blocked)
+ * has been released. The thieves stop taking beans once there are no beans left to take.
- * until the lock has been released. The thieves stop taking beans once there
- * are no beans left to take.
  */
 public class App {
 
   /**
-   * main method
+   * main method.
    */
   public static void main(String[] args) {
     Mutex mutex = new Mutex();

mutex/src/main/java/com/iluwatar/mutex/Jar.java

@@ -24,9 +24,8 @@
 package com.iluwatar.mutex;
 
 /**
- * A Jar has a resource of beans which can only be accessed by a single Thief
+ * A Jar has a resource of beans which can only be accessed by a single Thief (thread) at any one
- * (thread) at any one time. A Mutex lock is used to prevent more than one Thief
+ * time. A Mutex lock is used to prevent more than one Thief taking a bean simultaneously.
- * taking a bean simultaneously. 
  */
 public class Jar {
 

mutex/src/main/java/com/iluwatar/mutex/Mutex.java

@@ -34,16 +34,15 @@ public class Mutex implements Lock {
   private Object owner;
 
   /**
-   * Returns the current owner of the Mutex, or null if available
+   * Returns the current owner of the Mutex, or null if available.
    */
   public Object getOwner() {
     return owner;
   }
-  
+
   /**
-   * Method called by a thread to acquire the lock. If the lock has already
+   * Method called by a thread to acquire the lock. If the lock has already been acquired this will
-   * been acquired this will wait until the lock has been released to 
+   * wait until the lock has been released to re-attempt the acquire.
-   * re-attempt the acquire.
    */
   @Override
   public synchronized void acquire() throws InterruptedException {

mutex/src/main/java/com/iluwatar/mutex/Thief.java

@@ -27,20 +27,20 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Thief is a class which continually tries to acquire a jar and take a bean
+ * Thief is a class which continually tries to acquire a jar and take a bean from it. When the jar
- * from it. When the jar is empty the thief stops.
+ * is empty the thief stops.
  */
 public class Thief extends Thread {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(Thief.class);
 
   /**
-   * The name of the thief. 
+   * The name of the thief.
    */
   private final String name;
-  
+
   /**
-   * The jar
+   * The jar.
    */
   private final Jar jar;
 
@@ -50,8 +50,7 @@ public class Thief extends Thread {
   }
 
   /**
-   * In the run method the thief repeatedly tries to take a bean until none
+   * In the run method the thief repeatedly tries to take a bean until none are left.
-   * are left.
    */
   @Override
   public void run() {