Resolves checkstyle errors for facade factory-kit spatial-partition state step-builder (#1077)

* Reduces checkstyle errors in facade

* Reduces checkstyle errors in factory-kit

* Reduces checkstyle errors in spatial-partition

* Reduces checkstyle errors in state

* Reduces checkstyle errors in step-builder

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

@@ -24,23 +24,21 @@
 package com.iluwatar.facade;
 
 /**
- * 
  * The Facade design pattern is often used when a system is very complex or difficult to understand
  * because the system has a large number of interdependent classes or its source code is
  * unavailable. This pattern hides the complexities of the larger system and provides a simpler
  * interface to the client. It typically involves a single wrapper class which contains a set of
  * members required by client. These members access the system on behalf of the facade client and
  * hide the implementation details.
- * <p>
- * In this example the Facade is ({@link DwarvenGoldmineFacade}) and it provides a simpler interface
- * to the goldmine subsystem.
- * 
+ *
+ * <p>In this example the Facade is ({@link DwarvenGoldmineFacade}) and it provides a simpler
+ * interface to the goldmine subsystem.
  */
 public class App {
 
   /**
-   * Program entry point
-   * 
+   * Program entry point.
+   *
    * @param args command line args
    */
   public static void main(String[] args) {

facade/src/main/java/com/iluwatar/facade/DwarvenCartOperator.java

@@ -27,9 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
  * DwarvenCartOperator is one of the goldmine subsystems.
- *
  */
 public class DwarvenCartOperator extends DwarvenMineWorker {
 

facade/src/main/java/com/iluwatar/facade/DwarvenGoldDigger.java

@@ -27,9 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
  * DwarvenGoldDigger is one of the goldmine subsystems.
- *
  */
 public class DwarvenGoldDigger extends DwarvenMineWorker {
 

facade/src/main/java/com/iluwatar/facade/DwarvenGoldmineFacade.java

@@ -27,25 +27,24 @@ import java.util.Collection;
 import java.util.List;
 
 /**
- * 
- * DwarvenGoldmineFacade provides a single interface through which users can operate the subsystems.
- * 
- * This makes the goldmine easier to operate and cuts the dependencies from the goldmine user to the
+ * DwarvenGoldmineFacade provides a single interface through which users can operate the
  * subsystems.
  *
+ * <p>This makes the goldmine easier to operate and cuts the dependencies from the goldmine user to
+ * the subsystems.
  */
 public class DwarvenGoldmineFacade {
 
   private final List<DwarvenMineWorker> workers;
 
   /**
-   * Constructor
+   * Constructor.
    */
   public DwarvenGoldmineFacade() {
     workers = List.of(
-            new DwarvenGoldDigger(),
-            new DwarvenCartOperator(),
-            new DwarvenTunnelDigger());
+        new DwarvenGoldDigger(),
+        new DwarvenCartOperator(),
+        new DwarvenTunnelDigger());
   }
 
   public void startNewDay() {
@@ -60,8 +59,10 @@ public class DwarvenGoldmineFacade {
     makeActions(workers, DwarvenMineWorker.Action.GO_HOME, DwarvenMineWorker.Action.GO_TO_SLEEP);
   }
 
-  private static void makeActions(Collection<DwarvenMineWorker> workers,
-      DwarvenMineWorker.Action... actions) {
+  private static void makeActions(
+      Collection<DwarvenMineWorker> workers,
+      DwarvenMineWorker.Action... actions
+  ) {
     for (DwarvenMineWorker worker : workers) {
       worker.action(actions);
     }

facade/src/main/java/com/iluwatar/facade/DwarvenMineWorker.java

@@ -27,9 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
  * DwarvenMineWorker is one of the goldmine subsystems.
- *
  */
 public abstract class DwarvenMineWorker {
 
@@ -75,7 +73,7 @@ public abstract class DwarvenMineWorker {
   }
 
   /**
-   * Perform actions
+   * Perform actions.
    */
   public void action(Action... actions) {
     for (Action action : actions) {

facade/src/main/java/com/iluwatar/facade/DwarvenTunnelDigger.java

@@ -27,9 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
  * DwarvenTunnelDigger is one of the goldmine subsystems.
- *
  */
 public class DwarvenTunnelDigger extends DwarvenMineWorker {
 

factory-kit/src/main/java/com/iluwatar/factorykit/App.java

@@ -27,17 +27,16 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Factory-kit is a creational pattern which defines a factory of immutable content
- * with separated builder and factory interfaces to deal with the problem of
- * creating one of the objects specified directly in the factory-kit instance.
+ * Factory-kit is a creational pattern which defines a factory of immutable content with separated
+ * builder and factory interfaces to deal with the problem of creating one of the objects specified
+ * directly in the factory-kit instance.
  *
- * <p>
- * In the given example {@link WeaponFactory} represents the factory-kit, that contains
- * four {@link Builder}s for creating new objects of
- * the classes implementing {@link Weapon} interface.
- * <br>Each of them can be called with {@link WeaponFactory#create(WeaponType)} method, with
- * an input representing an instance of {@link WeaponType} that needs to
- * be mapped explicitly with desired class type in the factory instance.
+ * <p>In the given example {@link WeaponFactory} represents the factory-kit, that contains four
+ * {@link Builder}s for creating new objects of the classes implementing {@link Weapon} interface.
+ *
+ * <p>Each of them can be called with {@link WeaponFactory#create(WeaponType)} method, with
+ * an input representing an instance of {@link WeaponType} that needs to be mapped explicitly with
+ * desired class type in the factory instance.
  */
 public class App {
 

factory-kit/src/main/java/com/iluwatar/factorykit/Axe.java

@@ -24,7 +24,7 @@
 package com.iluwatar.factorykit;
 
 /**
- * Class representing Axe
+ * Class representing Axe.
  */
 public class Axe implements Weapon {
   @Override

factory-kit/src/main/java/com/iluwatar/factorykit/Bow.java

@@ -24,7 +24,7 @@
 package com.iluwatar.factorykit;
 
 /**
- * Class representing Bows
+ * Class representing Bows.
  */
 public class Bow implements Weapon {
   @Override

factory-kit/src/main/java/com/iluwatar/factorykit/Spear.java

@@ -22,8 +22,9 @@
  */
 
 package com.iluwatar.factorykit;
+
 /**
- * Class representing Spear
+ * Class representing Spear.
  */
 public class Spear implements Weapon {
   @Override

factory-kit/src/main/java/com/iluwatar/factorykit/Sword.java

@@ -22,8 +22,9 @@
  */
 
 package com.iluwatar.factorykit;
+
 /**
- * Class representing Swords
+ * Class representing Swords.
  */
 public class Sword implements Weapon {
   @Override

factory-kit/src/main/java/com/iluwatar/factorykit/WeaponFactory.java

@@ -39,6 +39,7 @@ public interface WeaponFactory {
 
   /**
    * Creates an instance of the given type.
+   *
    * @param name representing enum of an object type to be created.
    * @return new instance of a requested class implementing {@link Weapon} interface.
    */
@@ -46,6 +47,7 @@ public interface WeaponFactory {
 
   /**
    * Creates factory - placeholder for specified {@link Builder}s.
+   *
    * @param consumer for the new builder to the factory.
    * @return factory with specified {@link Builder}s
    */

factory-kit/src/main/java/com/iluwatar/factorykit/WeaponType.java

@@ -24,7 +24,7 @@
 package com.iluwatar.factorykit;
 
 /**
- * Enumerates {@link Weapon} types
+ * Enumerates {@link Weapon} types.
  */
 public enum WeaponType {
   SWORD, AXE, BOW, SPEAR

spatial-partition/src/main/java/com/iluwatar/spatialpartition/App.java

@@ -23,54 +23,60 @@
 
 package com.iluwatar.spatialpartition;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.Hashtable;
 import java.util.Random;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
- * <p>The idea behind the <b>Spatial Partition</b> design pattern is to enable efficient location of objects 
- * by storing them in a data structure that is organised by their positions. This is especially useful in the 
- * gaming world, where one may need to look up all the objects within a certain boundary, or near a certain 
- * other object, repeatedly. The data structure can be used to store moving and static objects, though in order 
- * to keep track of the moving objects, their positions will have to be reset each time they move. This would 
- * mean having to create a new instance of the data structure each frame, which would use up additional memory, 
- * and so this pattern should only be used if one does not mind trading memory for speed and the number of 
+ * <p>The idea behind the <b>Spatial Partition</b> design pattern is to enable efficient location
+ * of objects by storing them in a data structure that is organised by their positions. This is
+ * especially useful in the gaming world, where one may need to look up all the objects within a
+ * certain boundary, or near a certain other object, repeatedly. The data structure can be used to
+ * store moving and static objects, though in order to keep track of the moving objects, their
+ * positions will have to be reset each time they move. This would mean having to create a new
+ * instance of the data structure each frame, which would use up additional memory, and so this
+ * pattern should only be used if one does not mind trading memory for speed and the number of
  * objects to keep track of is large to justify the use of the extra space.</p>
- * <p>In our example, we use <b>{@link QuadTree} data structure</b> which divides into 4 (quad) sub-sections when 
- * the number of objects added to it exceeds a certain number (int field capacity). There is also a 
- * <b>{@link Rect}</b> class to define the boundary of the quadtree. We use an abstract class <b>{@link Point}</b> 
- * with x and y coordinate fields and also an id field so that it can easily be put and looked up in the hashtable. 
- * This class has abstract methods to define how the object moves (move()), when to check for collision with any 
- * object (touches(obj)) and how to handle collision (handleCollision(obj)), and will be extended by any object 
- * whose position has to be kept track of in the quadtree. The <b>{@link SpatialPartitionGeneric}</b> abstract class 
- * has 2 fields - a hashtable containing all objects (we use hashtable for faster lookups, insertion and deletion) 
- * and a quadtree, and contains an abstract method which defines how to handle interactions between objects using 
- * the quadtree.</p>
- * <p>Using the quadtree data structure will reduce the time complexity of finding the objects within a
- * certain range from <b>O(n^2) to O(nlogn)</b>, increasing the speed of computations immensely in case of
- * large number of objects, which will have a positive effect on the rendering speed of the game.</p>
+ * <p>In our example, we use <b>{@link QuadTree} data structure</b> which divides into 4 (quad)
+ * sub-sections when the number of objects added to it exceeds a certain number (int field
+ * capacity). There is also a
+ * <b>{@link Rect}</b> class to define the boundary of the quadtree. We use an abstract class
+ * <b>{@link Point}</b>
+ * with x and y coordinate fields and also an id field so that it can easily be put and looked up in
+ * the hashtable. This class has abstract methods to define how the object moves (move()), when to
+ * check for collision with any object (touches(obj)) and how to handle collision
+ * (handleCollision(obj)), and will be extended by any object whose position has to be kept track of
+ * in the quadtree. The <b>{@link SpatialPartitionGeneric}</b> abstract class has 2 fields - a
+ * hashtable containing all objects (we use hashtable for faster lookups, insertion and deletion)
+ * and a quadtree, and contains an abstract method which defines how to handle interactions between
+ * objects using the quadtree.</p>
+ * <p>Using the quadtree data structure will reduce the time complexity of finding the objects
+ * within a certain range from <b>O(n^2) to O(nlogn)</b>, increasing the speed of computations
+ * immensely in case of large number of objects, which will have a positive effect on the rendering
+ * speed of the game.</p>
  */
 
 public class App {
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
 
-  static void noSpatialPartition(int height, int width, 
-        int numOfMovements, Hashtable<Integer, Bubble> bubbles) {
+  static void noSpatialPartition(int height, int width,
+                                 int numOfMovements, Hashtable<Integer, Bubble> bubbles) {
     ArrayList<Point> bubblesToCheck = new ArrayList<Point>();
-    for (Enumeration<Integer> e = bubbles.keys(); e.hasMoreElements();) {
-      bubblesToCheck.add(bubbles.get(e.nextElement())); //all bubbles have to be checked for collision for all bubbles
+    for (Enumeration<Integer> e = bubbles.keys(); e.hasMoreElements(); ) {
+      bubblesToCheck.add(bubbles
+          .get(e.nextElement())); //all bubbles have to be checked for collision for all bubbles
     }
 
-        //will run numOfMovement times or till all bubbles have popped
+    //will run numOfMovement times or till all bubbles have popped
     while (numOfMovements > 0 && !bubbles.isEmpty()) {
-      for (Enumeration<Integer> e = bubbles.keys(); e.hasMoreElements();) {
+      for (Enumeration<Integer> e = bubbles.keys(); e.hasMoreElements(); ) {
         Integer i = e.nextElement();
-        //bubble moves, new position gets updated, collisions checked with all bubbles in bubblesToCheck
-        bubbles.get(i).move();  
+        // bubble moves, new position gets updated
+        // and collisions are checked with all bubbles in bubblesToCheck
+        bubbles.get(i).move();
         bubbles.replace(i, bubbles.get(i));
         bubbles.get(i).handleCollision(bubblesToCheck, bubbles);
       }
@@ -82,24 +88,24 @@ public class App {
     }
   }
 
-  static void withSpatialPartition(int height, int width, 
-        int numOfMovements, Hashtable<Integer, Bubble> bubbles) {
+  static void withSpatialPartition(
+      int height, int width, int numOfMovements, Hashtable<Integer, Bubble> bubbles) {
     //creating quadtree
-    Rect rect = new Rect(width / 2,height / 2,width,height);
-    QuadTree qTree = new QuadTree(rect, 4);
-    
+    Rect rect = new Rect(width / 2, height / 2, width, height);
+    QuadTree quadTree = new QuadTree(rect, 4);
+
     //will run numOfMovement times or till all bubbles have popped
     while (numOfMovements > 0 && !bubbles.isEmpty()) {
       //quadtree updated each time
-      for (Enumeration<Integer> e = bubbles.keys(); e.hasMoreElements();) {
-        qTree.insert(bubbles.get(e.nextElement()));
+      for (Enumeration<Integer> e = bubbles.keys(); e.hasMoreElements(); ) {
+        quadTree.insert(bubbles.get(e.nextElement()));
       }
-      for (Enumeration<Integer> e = bubbles.keys(); e.hasMoreElements();) {
+      for (Enumeration<Integer> e = bubbles.keys(); e.hasMoreElements(); ) {
         Integer i = e.nextElement();
         //bubble moves, new position gets updated, quadtree used to reduce computations
-        bubbles.get(i).move();  
+        bubbles.get(i).move();
         bubbles.replace(i, bubbles.get(i));
-        SpatialPartitionBubbles sp = new SpatialPartitionBubbles(bubbles, qTree);
+        SpatialPartitionBubbles sp = new SpatialPartitionBubbles(bubbles, quadTree);
         sp.handleCollisionsUsingQt(bubbles.get(i));
       }
       numOfMovements--;
@@ -109,7 +115,7 @@ public class App {
       LOGGER.info("Bubble " + key + " not popped");
     }
   }
-  
+
   /**
    * Program entry point.
    *
@@ -124,14 +130,15 @@ public class App {
       Bubble b = new Bubble(rand.nextInt(300), rand.nextInt(300), i, rand.nextInt(2) + 1);
       bubbles1.put(i, b);
       bubbles2.put(i, b);
-      LOGGER.info("Bubble " + i + " with radius " + b.radius + " added at (" + b.x + "," + b.y + ")");
+      LOGGER.info("Bubble " + i + " with radius " + b.radius
+          + " added at (" + b.coordinateX + "," + b.coordinateY + ")");
     }
 
     long start1 = System.currentTimeMillis();
-    App.noSpatialPartition(300,300,20,bubbles1);
+    App.noSpatialPartition(300, 300, 20, bubbles1);
     long end1 = System.currentTimeMillis();
     long start2 = System.currentTimeMillis();
-    App.withSpatialPartition(300,300,20,bubbles2);
+    App.withSpatialPartition(300, 300, 20, bubbles2);
     long end2 = System.currentTimeMillis();
     LOGGER.info("Without spatial partition takes " + (end1 - start1) + "ms");
     LOGGER.info("With spatial partition takes " + (end2 - start2) + "ms");

spatial-partition/src/main/java/com/iluwatar/spatialpartition/Bubble.java

@@ -23,16 +23,15 @@
 
 package com.iluwatar.spatialpartition;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.util.ArrayList;
 import java.util.Hashtable;
 import java.util.Random;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
- * Bubble class extends Point. In this example, we create several bubbles in the field,
- * let them move and keep track of which ones have popped and which ones remain.
+ * Bubble class extends Point. In this example, we create several bubbles in the field, let them
+ * move and keep track of which ones have popped and which ones remain.
  */
 
 public class Bubble extends Point<Bubble> {
@@ -42,24 +41,26 @@ public class Bubble extends Point<Bubble> {
   final int radius;
 
   Bubble(int x, int y, int id, int radius) {
-    super(x,y,id);
+    super(x, y, id);
     this.radius = radius;
   }
 
   void move() {
     //moves by 1 unit in either direction
-    this.x += RANDOM.nextInt(3) - 1;
-    this.y += RANDOM.nextInt(3) - 1;
+    this.coordinateX += RANDOM.nextInt(3) - 1;
+    this.coordinateY += RANDOM.nextInt(3) - 1;
   }
 
   boolean touches(Bubble b) {
     //distance between them is greater than sum of radii (both sides of equation squared)
-    return (this.x - b.x) * (this.x - b.x) + (this.y - b.y) * (this.y - b.y)
-                <= (this.radius + b.radius) * (this.radius + b.radius);
+    return (this.coordinateX - b.coordinateX) * (this.coordinateX - b.coordinateX)
+        + (this.coordinateY - b.coordinateY) * (this.coordinateY - b.coordinateY)
+        <= (this.radius + b.radius) * (this.radius + b.radius);
   }
 
   void pop(Hashtable<Integer, Bubble> allBubbles) {
-    LOGGER.info("Bubble " + this.id + " popped at (" + this.x + "," + this.y + ")!");
+    LOGGER.info("Bubble " + this.id
+        + " popped at (" + this.coordinateX + "," + this.coordinateY + ")!");
     allBubbles.remove(this.id);
   }
 
@@ -68,8 +69,8 @@ public class Bubble extends Point<Bubble> {
     for (int i = 0; i < bubblesToCheck.size(); i++) {
       Integer otherId = bubblesToCheck.get(i).id;
       if (allBubbles.get(otherId) != null && //the bubble hasn't been popped yet
-                    this.id != otherId && //the two bubbles are not the same
-                    this.touches(allBubbles.get(otherId))) { //the bubbles touch
+          this.id != otherId && //the two bubbles are not the same
+          this.touches(allBubbles.get(otherId))) { //the bubbles touch
         allBubbles.get(otherId).pop(allBubbles);
         toBePopped = true;
       }

spatial-partition/src/main/java/com/iluwatar/spatialpartition/Point.java

@@ -27,40 +27,42 @@ import java.util.ArrayList;
 import java.util.Hashtable;
 
 /**
- * The abstract Point class which will be extended by any object in the field
- * whose location has to be kept track of. Defined by x,y coordinates and an id
- * for easy hashing into hashtable.
+ * The abstract Point class which will be extended by any object in the field whose location has to
+ * be kept track of. Defined by x,y coordinates and an id for easy hashing into hashtable.
+ *
  * @param <T> T will be type subclass
  */
 
 public abstract class Point<T> {
 
-  public int x; 
-  public int y; 
+  public int coordinateX;
+  public int coordinateY;
   public final int id;
-  
+
   Point(int x, int y, int id) {
-    this.x = x;
-    this.y = y;
+    this.coordinateX = x;
+    this.coordinateY = y;
     this.id = id;
   }
 
   /**
-   * defines how the object moves
+   * defines how the object moves.
    */
   abstract void move();
-  
+
   /**
-   * defines conditions for interacting with an object obj
+   * defines conditions for interacting with an object obj.
+   *
    * @param obj is another object on field which also extends Point
    * @return whether the object can interact with the other or not
    */
   abstract boolean touches(T obj);
-  
+
   /**
-   * handling interactions/collisions with other objects
+   * handling interactions/collisions with other objects.
+   *
    * @param pointsToCheck contains the objects which need to be checked
-   * @param allPoints contains hashtable of all points on field at this time
+   * @param allPoints     contains hashtable of all points on field at this time
    */
   abstract void handleCollision(ArrayList<Point> pointsToCheck, Hashtable<Integer, T> allPoints);
 }

spatial-partition/src/main/java/com/iluwatar/spatialpartition/QuadTree.java

@@ -28,9 +28,9 @@ import java.util.Enumeration;
 import java.util.Hashtable;
 
 /**
- * The quadtree data structure is being used to keep track of the objects' locations.
- * It has the insert(Point) and query(range) methods to insert a new object and find
- * the objects within a certain (rectangular) range respectively.
+ * The quadtree data structure is being used to keep track of the objects' locations. It has the
+ * insert(Point) and query(range) methods to insert a new object and find the objects within a
+ * certain (rectangular) range respectively.
  */
 
 public class QuadTree {
@@ -48,9 +48,9 @@ public class QuadTree {
     this.capacity = capacity;
     this.divided = false;
     this.points = new Hashtable<Integer, Point>();
-    this.northwest = null; 
-    this.northeast = null; 
-    this.southwest = null; 
+    this.northwest = null;
+    this.northeast = null;
+    this.southwest = null;
     this.southeast = null;
   }
 
@@ -76,25 +76,25 @@ public class QuadTree {
   }
 
   void divide() {
-    Rect nw = new Rect(this.boundary.x - this.boundary.width / 4, this.boundary.y + this.boundary.height / 4, 
-          this.boundary.width / 2, this.boundary.height / 2);
-    this.northwest = new QuadTree(nw , this.capacity);
-    Rect ne = new Rect(this.boundary.x + this.boundary.width / 4, this.boundary.y + this.boundary.height / 4, 
-          this.boundary.width / 2, this.boundary.height / 2);
-    this.northeast = new QuadTree(ne , this.capacity);
-    Rect sw = new Rect(this.boundary.x - this.boundary.width / 4, this.boundary.y - this.boundary.height / 4, 
-          this.boundary.width / 2, this.boundary.height / 2);
-    this.southwest = new QuadTree(sw , this.capacity);
-    Rect se = new Rect(this.boundary.x + this.boundary.width / 4, this.boundary.y - this.boundary.height / 4, 
-          this.boundary.width / 2, this.boundary.height / 2);
-    this.southeast = new QuadTree(se , this.capacity);
+    double x = this.boundary.coordinateX;
+    double y = this.boundary.coordinateY;
+    double width = this.boundary.width;
+    double height = this.boundary.height;
+    Rect nw = new Rect(x - width / 4, y + height / 4, width / 2, height / 2);
+    this.northwest = new QuadTree(nw, this.capacity);
+    Rect ne = new Rect(x + width / 4, y + height / 4, width / 2, height / 2);
+    this.northeast = new QuadTree(ne, this.capacity);
+    Rect sw = new Rect(x - width / 4, y - height / 4, width / 2, height / 2);
+    this.southwest = new QuadTree(sw, this.capacity);
+    Rect se = new Rect(x + width / 4, y - height / 4, width / 2, height / 2);
+    this.southeast = new QuadTree(se, this.capacity);
     this.divided = true;
   }
 
   ArrayList<Point> query(Rect r, ArrayList<Point> relevantPoints) {
     //could also be a circle instead of a rectangle
     if (this.boundary.intersects(r)) {
-      for (Enumeration<Integer> e = this.points.keys(); e.hasMoreElements();) {
+      for (Enumeration<Integer> e = this.points.keys(); e.hasMoreElements(); ) {
         Integer i = e.nextElement();
         if (r.contains(this.points.get(i))) {
           relevantPoints.add(this.points.get(i));

spatial-partition/src/main/java/com/iluwatar/spatialpartition/Rect.java

@@ -24,35 +24,37 @@
 package com.iluwatar.spatialpartition;
 
 /**
- * The Rect class helps in defining the boundary of the quadtree and is also used to
- * define the range within which objects need to be found in our example.
+ * The Rect class helps in defining the boundary of the quadtree and is also used to define the
+ * range within which objects need to be found in our example.
  */
 
 public class Rect {
-  double x;
-  double y;
+  double coordinateX;
+  double coordinateY;
   double width;
   double height;
 
   //(x,y) - centre of rectangle
 
   Rect(double x, double y, double width, double height) {
-    this.x = x;
-    this.y = y;
+    this.coordinateX = x;
+    this.coordinateY = y;
     this.width = width;
     this.height = height;
   }
 
   boolean contains(Point p) {
-    return p.x >= this.x - this.width / 2 && p.x <= this.x + this.width / 2
-        && p.y >= this.y - this.height / 2 && p.y <= this.y + this.height / 2;
+    return p.coordinateX >= this.coordinateX - this.width / 2
+        && p.coordinateX <= this.coordinateX + this.width / 2
+        && p.coordinateY >= this.coordinateY - this.height / 2
+        && p.coordinateY <= this.coordinateY + this.height / 2;
   }
 
   boolean intersects(Rect other) {
-    return !(this.x + this.width / 2 <= other.x - other.width / 2 
-          || this.x - this.width / 2 >= other.x + other.width / 2 
-          || this.y + this.height / 2 <= other.y - other.height / 2 
-          || this.y - this.height / 2 >= other.y + other.height / 2);
+    return !(this.coordinateX + this.width / 2 <= other.coordinateX - other.width / 2
+        || this.coordinateX - this.width / 2 >= other.coordinateX + other.width / 2
+        || this.coordinateY + this.height / 2 <= other.coordinateY - other.height / 2
+        || this.coordinateY - this.height / 2 >= other.coordinateY + other.height / 2);
   }
 }
 

spatial-partition/src/main/java/com/iluwatar/spatialpartition/SpatialPartitionBubbles.java

@@ -27,25 +27,26 @@ import java.util.ArrayList;
 import java.util.Hashtable;
 
 /**
- * This class extends the generic SpatialPartition abstract class and is used in
- * our example to keep track of all the bubbles that collide, pop and stay un-popped.
+ * This class extends the generic SpatialPartition abstract class and is used in our example to keep
+ * track of all the bubbles that collide, pop and stay un-popped.
  */
 
 public class SpatialPartitionBubbles extends SpatialPartitionGeneric<Bubble> {
 
-  Hashtable<Integer, Bubble> bubbles;
-  QuadTree qTree;
+  final Hashtable<Integer, Bubble> bubbles;
+  final QuadTree quadTree;
 
-  SpatialPartitionBubbles(Hashtable<Integer, Bubble> bubbles, QuadTree qTree) {
+  SpatialPartitionBubbles(Hashtable<Integer, Bubble> bubbles, QuadTree quadTree) {
     this.bubbles = bubbles;
-    this.qTree = qTree;
+    this.quadTree = quadTree;
   }
 
   void handleCollisionsUsingQt(Bubble b) {
-    //finding points within area of a square drawn with centre same as centre of bubble and length = radius of bubble
-    Rect rect = new Rect(b.x, b.y, 2 * b.radius, 2 * b.radius);
+    // finding points within area of a square drawn with centre same as
+    // centre of bubble and length = radius of bubble
+    Rect rect = new Rect(b.coordinateX, b.coordinateY, 2 * b.radius, 2 * b.radius);
     ArrayList<Point> quadTreeQueryResult = new ArrayList<Point>();
-    this.qTree.query(rect, quadTreeQueryResult);
+    this.quadTree.query(rect, quadTreeQueryResult);
     //handling these collisions
     b.handleCollision(quadTreeQueryResult, this.bubbles);
   }

spatial-partition/src/main/java/com/iluwatar/spatialpartition/SpatialPartitionGeneric.java

@@ -26,18 +26,20 @@ package com.iluwatar.spatialpartition;
 import java.util.Hashtable;
 
 /**
- * This abstract class has 2 fields, one of which is a hashtable containing all objects
- * that currently exist on the field and a quadtree which keeps track of locations.
+ * This abstract class has 2 fields, one of which is a hashtable containing all objects that
+ * currently exist on the field and a quadtree which keeps track of locations.
+ *
  * @param <T> T will be type of object (that extends Point)
  */
 
 public abstract class SpatialPartitionGeneric<T> {
 
   Hashtable<Integer, T> playerPositions;
-  QuadTree qTree;
+  QuadTree quadTree;
 
   /**
-   * handles collisions for object obj using quadtree
+   * handles collisions for object obj using quadtree.
+   *
    * @param obj is the object for which collisions need to be checked
    */
   abstract void handleCollisionsUsingQt(T obj);

spatial-partition/src/test/java/com/iluwatar/spatialpartition/BubbleTest.java

@@ -37,11 +37,11 @@ class BubbleTest {
   @Test
   void moveTest() {
     Bubble b = new Bubble(10,10,1,2);
-    int initialX = b.x;
-    int initialY = b.y;
+    int initialX = b.coordinateX;
+    int initialY = b.coordinateY;
     b.move();
     //change in x and y < |2|
-    assertTrue((b.x - initialX < 2 && b.x - initialX > -2) && (b.y - initialY < 2 && b.y - initialY > -2));
+    assertTrue((b.coordinateX - initialX < 2 && b.coordinateX - initialX > -2) && (b.coordinateY - initialY < 2 && b.coordinateY - initialY > -2));
   }
 
   @Test

state/src/main/java/com/iluwatar/state/AngryState.java

@@ -27,9 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
  * Angry state.
- *
  */
 public class AngryState implements State {
 

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

@@ -24,20 +24,18 @@
 package com.iluwatar.state;
 
 /**
- * 
  * In State pattern the container object has an internal state object that defines the current
  * behavior. The state object can be changed to alter the behavior.
- * <p>
- * This can be a cleaner way for an object to change its behavior at runtime without resorting to
- * large monolithic conditional statements and thus improves maintainability.
- * <p>
- * In this example the {@link Mammoth} changes its behavior as time passes by.
- * 
+ *
+ * <p>This can be a cleaner way for an object to change its behavior at runtime without resorting
+ * to large monolithic conditional statements and thus improves maintainability.
+ *
+ * <p>In this example the {@link Mammoth} changes its behavior as time passes by.
  */
 public class App {
 
   /**
-   * Program entry point
+   * Program entry point.
    */
   public static void main(String[] args) {
 

state/src/main/java/com/iluwatar/state/Mammoth.java

@@ -24,9 +24,7 @@
 package com.iluwatar.state;
 
 /**
- * 
  * Mammoth has internal state that defines its behavior.
- * 
  */
 public class Mammoth {
 
@@ -37,7 +35,7 @@ public class Mammoth {
   }
 
   /**
-   * Makes time pass for the mammoth
+   * Makes time pass for the mammoth.
    */
   public void timePasses() {
     if (state.getClass().equals(PeacefulState.class)) {

state/src/main/java/com/iluwatar/state/PeacefulState.java

@@ -27,9 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
  * Peaceful state.
- *
  */
 public class PeacefulState implements State {
 

state/src/main/java/com/iluwatar/state/State.java

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

step-builder/src/main/java/com/iluwatar/stepbuilder/App.java

@@ -29,15 +29,13 @@ import org.slf4j.LoggerFactory;
 /**
  * Step Builder Pattern
  *
- * <p>
- * <b>Intent</b> <br>
+ * <p><b>Intent</b> <br>
  * An extension of the Builder pattern that fully guides the user through the creation of the object
- * with no chances of confusion. <br>
- * The user experience will be much more improved by the fact that he will only see the next step
- * methods available, NO build method until is the right time to build the object.
+ * with no chances of confusion. <br> The user experience will be much more improved by the fact
+ * that he will only see the next step methods available, NO build method until is the right time to
+ * build the object.
  *
- * <p>
- * <b>Implementation</b> <br>
+ * <p><b>Implementation</b> <br>
  * The concept is simple:
  * <ul>
  *
@@ -49,13 +47,13 @@ import org.slf4j.LoggerFactory;
  * <li>Last step is the BuildStep, in charge of creating the object you need to build.</li>
  * </ul>
  *
- * <p>
- * <b>Applicability</b> <br>
+ * <p><b>Applicability</b> <br>
  * Use the Step Builder pattern when the algorithm for creating a complex object should be
  * independent of the parts that make up the object and how they're assembled the construction
  * process must allow different representations for the object that's constructed when in the
  * process of constructing the order is important.
- * <p>
+ * <br>
+ *
  * @see <a href="http://rdafbn.blogspot.co.uk/2012/07/step-builder-pattern_28.html">http://rdafbn.blogspot.co.uk/2012/07/step-builder-pattern_28.html</a>
  */
 public class App {
@@ -63,8 +61,8 @@ 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) {

step-builder/src/main/java/com/iluwatar/stepbuilder/Character.java

@@ -93,13 +93,13 @@ public class Character {
   public String toString() {
     var sb = new StringBuilder();
     sb.append("This is a ")
-            .append(fighterClass != null ? fighterClass : wizardClass)
-            .append(" named ")
-            .append(name)
-            .append(" armed with a ")
-            .append(weapon != null ? weapon : spell != null ? spell : "with nothing")
-            .append(abilities != null ? " and wielding " + abilities + " abilities" : "")
-            .append('.');
+        .append(fighterClass != null ? fighterClass : wizardClass)
+        .append(" named ")
+        .append(name)
+        .append(" armed with a ")
+        .append(weapon != null ? weapon : spell != null ? spell : "with nothing")
+        .append(abilities != null ? " and wielding " + abilities + " abilities" : "")
+        .append('.');
     return sb.toString();
   }
 }

step-builder/src/main/java/com/iluwatar/stepbuilder/CharacterStepBuilder.java

@@ -31,7 +31,8 @@ import java.util.List;
  */
 public final class CharacterStepBuilder {
 
-  private CharacterStepBuilder() {}
+  private CharacterStepBuilder() {
+  }
 
   public static NameStep newBuilder() {
     return new CharacterSteps();