change according to cgeckstyle

saga/README.md

@@ -1,7 +1,7 @@
 ---
 layout: pattern
 title: Saga
-folder: Communication
+folder: saga
 permalink: /patterns/saga/
 categories: Behavioral
 tags:
@@ -43,4 +43,4 @@ Use the Saga pattern, if:
 - you can not use 2PC(two phase commit)
 
 ## Credits
-- [pattern description](https://microservices.io/patterns/data/saga.html)
+- [Pattern: Saga](https://microservices.io/patterns/data/saga.html)

saga/pom.xml

@@ -23,7 +23,8 @@
     THE SOFTWARE.
 
 -->
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+         xmlns="http://maven.apache.org/POM/4.0.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
     <modelVersion>4.0.0</modelVersion>
     <parent>

saga/src/main/java/com/iluwatar/saga/choreography/ChoreographyChapter.java

@@ -24,14 +24,15 @@ package com.iluwatar.saga.choreography;
 
 
 /**
- * Chapter is an interface representing a contract for an external service.
+ * ChoreographyChapter is an interface representing a contract for an external service.
  * In that case, a service needs to make a decision what to do further
  * hence the server needs to get all context representing {@link Saga}
- * */
-public interface Chapter {
+ */
+public interface ChoreographyChapter {
 
   /**
    * In that case, every method is responsible to make a decision on what to do then
+   *
    * @param saga incoming saga
    * @return saga result
    */
@@ -44,6 +45,7 @@ public interface Chapter {
 
   /**
    * The operation executed in general case.
+   *
    * @param saga incoming saga
    * @return result {@link Saga}
    */
@@ -51,6 +53,7 @@ public interface Chapter {
 
   /**
    * The operation executed in rollback case.
+   *
    * @param saga incoming saga
    * @return result {@link Saga}
    */

saga/src/main/java/com/iluwatar/saga/choreography/Saga.java

@@ -29,7 +29,7 @@ import java.util.List;
 /**
  * Saga representation.
  * Saga consists of chapters.
- * Every Chapter is executed a certain service.
+ * Every ChoreographyChapter is executed a certain service.
  */
 public class Saga {
 
@@ -42,17 +42,37 @@ public class Saga {
   public static Saga create() {
     return new Saga();
   }
+
+  /**
+   * get resuzlt of saga
+   *
+   * @return result of saga @see {@link SagaResult}
+   */
   public SagaResult getResult() {
-        return !finished ?
-                SagaResult.PROGRESS :
-                forward ?
-                        SagaResult.FINISHED :
-                        SagaResult.ROLLBACKED;
+    if (finished) {
+      return forward
+          ? SagaResult.FINISHED
+          : SagaResult.ROLLBACKED;
     }
+
+    return SagaResult.PROGRESS;
+  }
+
+  /**
+   * add chapter to saga
+   * @param name chapter name
+   * @return this
+   */
   public Saga chapter(String name) {
     this.chapters.add(new Chapter(name));
     return this;
   }
+
+  /**
+   * set value to last chapter
+   * @param value invalue
+   * @return this
+   */
   public Saga setInValue(Object value) {
     if (chapters.isEmpty()) {
       return this;
@@ -60,12 +80,27 @@ public class Saga {
     chapters.get(chapters.size() - 1).setInValue(value);
     return this;
   }
+
+  /**
+   * get value from current chapter
+   * @return value
+   */
   public Object getCurrentValue() {
     return chapters.get(pos).getInValue();
   }
+
+  /**
+   * set value to current chapter
+   * @param value to set
+   */
   public void setCurrentValue(Object value) {
     chapters.get(pos).setInValue(value);
   }
+
+  /**
+   * set status for current chapter
+   * @param result to set
+   */
   public void setCurrentStatus(ChapterResult result) {
     chapters.get(pos).setResult(result);
   }
@@ -73,9 +108,11 @@ public class Saga {
   void setFinished(boolean finished) {
     this.finished = finished;
   }
+
   boolean isForward() {
     return forward;
   }
+
   int forward() {
     return ++pos;
   }
@@ -86,7 +123,7 @@ public class Saga {
   }
 
 
-    public Saga() {
+  private Saga() {
     this.chapters = new ArrayList<>();
     this.pos = 0;
     this.forward = true;
@@ -101,6 +138,7 @@ public class Saga {
   boolean isPresent() {
     return pos >= 0 && pos < chapters.size();
   }
+
   boolean isCurrentSuccess() {
     return chapters.get(pos).isSuccess();
   }
@@ -130,30 +168,48 @@ public class Saga {
     public String getName() {
       return name;
     }
+
+    /**
+     * set result
+     * @param result {@link ChapterResult}
+     */
     public void setResult(ChapterResult result) {
       this.result = result;
     }
 
+    /**
+     * the result for chapter is good
+     * @return true if is good otherwise bad
+     */
     public boolean isSuccess() {
       return result == ChapterResult.SUCCESS;
     }
   }
 
 
+  /**
+   * result for chapter
+   */
   public enum ChapterResult {
     INIT, SUCCESS, ROLLBACK
   }
 
+  /**
+   * result for saga
+   */
   public enum SagaResult {
     PROGRESS, FINISHED, ROLLBACKED
   }
 
   @Override
   public String toString() {
-        return "Saga{" +
-                "chapters=" + Arrays.toString(chapters.toArray()) +
-                ", pos=" + pos +
-                ", forward=" + forward +
-                '}';
+    return "Saga{"
+        + "chapters="
+        + Arrays.toString(chapters.toArray())
+        + ", pos="
+        + pos
+        + ", forward="
+        + forward
+        + '}';
   }
 }

saga/src/main/java/com/iluwatar/saga/choreography/SagaApplication.java

@@ -44,14 +44,17 @@ import org.slf4j.LoggerFactory;
  * @see Service
  */
 public class SagaApplication {
-    private static final Logger logger = LoggerFactory.getLogger(SagaApplication.class);
+  private static final Logger LOGGER = LoggerFactory.getLogger(SagaApplication.class);
 
+  /**
+   * main method
+   */
   public static void main(String[] args) {
     ServiceDiscoveryService sd = serviceDiscovery();
-        Chapter service = sd.findAny();
+    ChoreographyChapter service = sd.findAny();
     Saga goodOrderSaga = service.execute(newSaga("good_order"));
     Saga badOrderSaga = service.execute(newSaga("bad_order"));
-        logger.info("orders: goodOrder is {}, badOrder is {}",
+    LOGGER.info("orders: goodOrder is {}, badOrder is {}",
         goodOrderSaga.getResult(), badOrderSaga.getResult());
 
   }

saga/src/main/java/com/iluwatar/saga/choreography/Service.java

@@ -25,12 +25,14 @@ package com.iluwatar.saga.choreography;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.function.Supplier;
+
 /**
  * Common abstraction class representing services
- * implementing a general contract @see {@link Chapter}
+ * implementing a general contract @see {@link ChoreographyChapter}
  */
-public abstract class Service implements Chapter {
-    protected static final Logger logger = LoggerFactory.getLogger(Service.class);
+public abstract class Service implements ChoreographyChapter {
+  protected static final Logger LOGGER = LoggerFactory.getLogger(Service.class);
 
   private final ServiceDiscoveryService sd;
 
@@ -67,13 +69,17 @@ public abstract class Service implements Chapter {
     Saga finalNextSaga = nextSaga;
 
     return sd.find(chapterName).map(ch -> ch.execute(finalNextSaga))
-                .orElseThrow(RuntimeException::new);
+        .orElseThrow(serviceNotFoundException(chapterName));
+  }
+
+  private Supplier<RuntimeException> serviceNotFoundException(String chServiceName) {
+    return () -> new RuntimeException(String.format("the service %s has not been found", chServiceName));
   }
 
   @Override
   public Saga process(Saga saga) {
     Object inValue = saga.getCurrentValue();
-        logger.info("The chapter '{}' has been started. The data {} has been stored or calculated successfully",
+    LOGGER.info("The chapter '{}' has been started. The data {} has been stored or calculated successfully",
         getName(), inValue);
     saga.setCurrentStatus(Saga.ChapterResult.SUCCESS);
     saga.setCurrentValue(inValue);
@@ -83,7 +89,7 @@ public abstract class Service implements Chapter {
   @Override
   public Saga rollback(Saga saga) {
     Object inValue = saga.getCurrentValue();
-        logger.info("The Rollback for a chapter '{}' has been started. The data {} has been rollbacked successfully",
+    LOGGER.info("The Rollback for a chapter '{}' has been started. The data {} has been rollbacked successfully",
         getName(), inValue);
 
     saga.setCurrentStatus(Saga.ChapterResult.ROLLBACK);
@@ -94,7 +100,7 @@ public abstract class Service implements Chapter {
   private boolean isSagaFinished(Saga saga) {
     if (!saga.isPresent()) {
       saga.setFinished(true);
-            logger.info(" the saga has been finished with {} status", saga.getResult());
+      LOGGER.info(" the saga has been finished with {} status", saga.getResult());
       return true;
     }
     return false;

saga/src/main/java/com/iluwatar/saga/choreography/ServiceDiscoveryService.java

@@ -32,22 +32,23 @@ import java.util.Optional;
  * The class representing a service discovery pattern.
  */
 public class ServiceDiscoveryService {
-    private Map<String, Chapter> services;
+  private Map<String, ChoreographyChapter> services;
 
   /**
    * find any service
+   *
    * @return any service
    * @throws NoSuchElementException if no elements further
    */
-    public Chapter findAny(){
+  public ChoreographyChapter findAny() {
     return services.values().iterator().next();
   }
 
-    public Optional<Chapter> find(String service) {
+  public Optional<ChoreographyChapter> find(String service) {
     return Optional.ofNullable(services.getOrDefault(service, null));
   }
 
-    public ServiceDiscoveryService discover(Chapter chapterService) {
+  public ServiceDiscoveryService discover(ChoreographyChapter chapterService) {
     services.put(chapterService.getName(), chapterService);
     return this;
   }

saga/src/main/java/com/iluwatar/saga/choreography/WithdrawMoneyService.java

@@ -42,8 +42,8 @@ public class WithdrawMoneyService extends Service {
     Object inValue = saga.getCurrentValue();
 
     if (inValue.equals("bad_order")) {
-            logger.info("The chapter '{}' has been started. But the exception has been raised." +
-                            "The rollback is about to start",
+      LOGGER.info("The chapter '{}' has been started. But the exception has been raised."
+              + "The rollback is about to start",
           getName(), inValue);
       saga.setCurrentStatus(Saga.ChapterResult.ROLLBACK);
       return saga;

saga/src/main/java/com/iluwatar/saga/orchestration/ChapterResult.java

@@ -24,6 +24,7 @@ package com.iluwatar.saga.orchestration;
 
 /**
  * Executing result for chapter
+ *
  * @param <K> incoming value
  */
 public class ChapterResult<K> {
@@ -51,6 +52,9 @@ public class ChapterResult<K> {
     return new ChapterResult<>(val, State.FAILURE);
   }
 
+  /**
+   * state for chapter
+   */
   public enum State {
     SUCCESS, FAILURE
   }

saga/src/main/java/com/iluwatar/saga/orchestration/HotelBookingService.java

@@ -35,14 +35,14 @@ public class HotelBookingService extends Service<String> {
   @Override
   public ChapterResult<String> rollback(String value) {
     if (value.equals("crashed_order")) {
-            logger.info("The Rollback for a chapter '{}' has been started. " +
-                            "The data {} has been failed.The saga has been crashed.",
+      LOGGER.info("The Rollback for a chapter '{}' has been started. "
+              + "The data {} has been failed.The saga has been crashed.",
           getName(), value);
 
       return ChapterResult.failure(value);
     }
 
-        logger.info("The Rollback for a chapter '{}' has been started. The data {} has been rollbacked successfully",
+    LOGGER.info("The Rollback for a chapter '{}' has been started. The data {} has been rollbacked successfully",
         getName(), value);
 
     return super.rollback(value);

saga/src/main/java/com/iluwatar/saga/orchestration/OrchestrationChapter.java

@@ -23,10 +23,11 @@
 package com.iluwatar.saga.orchestration;
 
 /**
- * Chapter is an interface representing a contract for an external service.
+ * ChoreographyChapter is an interface representing a contract for an external service.
+ *
  * @param <K> is type for passing params
  */
-public interface Chapter<K> {
+public interface OrchestrationChapter<K> {
 
   /**
    * @return service name.
@@ -35,6 +36,7 @@ public interface Chapter<K> {
 
   /**
    * The operation executed in general case.
+   *
    * @param value incoming value
    * @return result {@link ChapterResult}
    */
@@ -42,6 +44,7 @@ public interface Chapter<K> {
 
   /**
    * The operation executed in rollback case.
+   *
    * @param value incoming value
    * @return result {@link ChapterResult}
    */

saga/src/main/java/com/iluwatar/saga/orchestration/Saga.java

@@ -28,13 +28,14 @@ import java.util.List;
 /**
  * Saga representation.
  * Saga consists of chapters.
- * Every Chapter is executed by a certain service.
+ * Every ChoreographyChapter is executed by a certain service.
  */
 public class Saga {
 
   private List<Chapter> chapters;
 
-    public Saga() {
+
+  private Saga() {
     this.chapters = new ArrayList<>();
   }
 
@@ -58,10 +59,16 @@ public class Saga {
     return new Saga();
   }
 
+  /**
+   * result for saga
+   */
   public enum Result {
     FINISHED, ROLLBACK, CRASHED
   }
 
+  /**
+   * class represents chapter name
+   */
   public static class Chapter {
     String name;
 

saga/src/main/java/com/iluwatar/saga/orchestration/SagaApplication.java

@@ -31,11 +31,12 @@ import org.slf4j.LoggerFactory;
  * This pattern is used in distributed services to perform a group of operations atomically.
  * This is an analog of transaction in a database but in terms of microservices architecture this is executed
  * in a distributed environment
- *
+ * <p>
  * A saga is a sequence of local transactions in a certain context. If one transaction fails for some reason,
  * the saga executes compensating transactions(rollbacks) to undo the impact of the preceding transactions.
- *
- * In this approach, there is an orchestrator @see {@link SagaOrchestrator} that manages all the transactions and directs
+ * <p>
+ * In this approach, there is an orchestrator @see {@link SagaOrchestrator}
+ * that manages all the transactions and directs
  * the participant services to execute local transactions based on events.
  * The major difference with choreography saga is an ability to handle crashed services
  * (otherwise in choreography services very hard to prevent a saga if one of them has been crashed)
@@ -45,8 +46,11 @@ import org.slf4j.LoggerFactory;
  * @see Service
  */
 public class SagaApplication {
-    private static final Logger logger = LoggerFactory.getLogger(SagaApplication.class);
+  private static final Logger LOGGER = LoggerFactory.getLogger(SagaApplication.class);
 
+  /**
+   * method to show common saga logic
+   */
   public static void main(String[] args) {
     SagaOrchestrator sagaOrchestrator = new SagaOrchestrator(newSaga(), serviceDiscovery());
 
@@ -54,7 +58,7 @@ public class SagaApplication {
     Saga.Result badOrder = sagaOrchestrator.execute("bad_order");
     Saga.Result crashedOrder = sagaOrchestrator.execute("crashed_order");
 
-        logger.info("orders: goodOrder is {}, badOrder is {},crashedOrder is {}",goodOrder,badOrder,crashedOrder);
+    LOGGER.info("orders: goodOrder is {}, badOrder is {},crashedOrder is {}", goodOrder, badOrder, crashedOrder);
   }
 
 

saga/src/main/java/com/iluwatar/saga/orchestration/SagaOrchestrator.java

@@ -34,12 +34,17 @@ import static com.iluwatar.saga.orchestration.Saga.Result.*;
  * the participant services to execute local transactions based on events.
  */
 public class SagaOrchestrator {
-    private static final Logger logger = LoggerFactory.getLogger(SagaOrchestrator.class);
+  private static final Logger LOGGER = LoggerFactory.getLogger(SagaOrchestrator.class);
   private final Saga saga;
   private final ServiceDiscoveryService sd;
   private final CurrentState state;
 
 
+  /**
+   * Create a new service to orchetrate sagas
+   * @param saga saga to process
+   * @param sd service discovery @see {@link ServiceDiscoveryService}
+   */
   public SagaOrchestrator(Saga saga, ServiceDiscoveryService sd) {
     this.saga = saga;
     this.sd = sd;
@@ -56,14 +61,14 @@ public class SagaOrchestrator {
   @SuppressWarnings("unchecked")
   public <K> Saga.Result execute(K value) {
     state.cleanUp();
-        logger.info(" The new saga is about to start");
+    LOGGER.info(" The new saga is about to start");
     Saga.Result result = FINISHED;
     K tempVal = value;
 
     while (true) {
       int next = state.current();
       Saga.Chapter ch = saga.get(next);
-            Optional<Chapter> srvOpt = sd.find(ch.name);
+      Optional<OrchestrationChapter> srvOpt = sd.find(ch.name);
 
       if (!srvOpt.isPresent()) {
         state.directionToBack();
@@ -71,7 +76,7 @@ public class SagaOrchestrator {
         continue;
       }
 
-            Chapter srv = srvOpt.get();
+      OrchestrationChapter srv = srvOpt.get();
 
       if (state.isForward()) {
         ChapterResult processRes = srv.process(tempVal);

saga/src/main/java/com/iluwatar/saga/orchestration/Service.java

@@ -27,11 +27,12 @@ import org.slf4j.LoggerFactory;
 
 /**
  * Common abstraction class representing services
- * implementing a general contract @see {@link Chapter}
+ * implementing a general contract @see {@link OrchestrationChapter}
+ *
  * @param <K> type of incoming param
  */
-public abstract class Service<K> implements Chapter<K> {
-    protected static final Logger logger = LoggerFactory.getLogger(Service.class);
+public abstract class Service<K> implements OrchestrationChapter<K> {
+  protected static final Logger LOGGER = LoggerFactory.getLogger(Service.class);
 
   @Override
   public abstract String getName();
@@ -39,14 +40,14 @@ public abstract class Service<K> implements Chapter<K> {
 
   @Override
   public ChapterResult<K> process(K value) {
-        logger.info("The chapter '{}' has been started. The data {} has been stored or calculated successfully",
+    LOGGER.info("The chapter '{}' has been started. The data {} has been stored or calculated successfully",
         getName(), value);
     return ChapterResult.success(value);
   }
 
   @Override
   public ChapterResult<K> rollback(K value) {
-        logger.info("The Rollback for a chapter '{}' has been started. The data {} has been rollbacked successfully",
+    LOGGER.info("The Rollback for a chapter '{}' has been started. The data {} has been rollbacked successfully",
         getName(), value);
     return ChapterResult.success(value);
   }

saga/src/main/java/com/iluwatar/saga/orchestration/ServiceDiscoveryService.java

@@ -30,14 +30,14 @@ import java.util.Optional;
  * The class representing a service discovery pattern.
  */
 public class ServiceDiscoveryService {
-    private Map<String, Chapter<?>> services;
+  private Map<String, OrchestrationChapter<?>> services;
 
-    public Optional<Chapter> find(String service) {
+  public Optional<OrchestrationChapter> find(String service) {
     return Optional.ofNullable(services.getOrDefault(service, null));
   }
 
-    public ServiceDiscoveryService discover(Chapter<?> chapterService) {
-        services.put(chapterService.getName(), chapterService);
+  public ServiceDiscoveryService discover(OrchestrationChapter<?> orchestrationChapterService) {
+    services.put(orchestrationChapterService.getName(), orchestrationChapterService);
     return this;
   }
 

saga/src/main/java/com/iluwatar/saga/orchestration/WithdrawMoneyService.java

@@ -34,8 +34,8 @@ public class WithdrawMoneyService extends Service<String> {
   @Override
   public ChapterResult<String> process(String value) {
     if (value.equals("bad_order") || value.equals("crashed_order")) {
-            logger.info("The chapter '{}' has been started. But the exception has been raised." +
-                            "The rollback is about to start",
+      LOGGER.info("The chapter '{}' has been started. But the exception has been raised."
+              + "The rollback is about to start",
           getName(), value);
       return ChapterResult.failure(value);
     }

saga/src/test/java/com/iluwatar/saga/choreography/SagaApplicationTest.java

@@ -25,8 +25,10 @@ package com.iluwatar.saga.choreography;
 import com.iluwatar.saga.orchestration.SagaApplication;
 import org.junit.Test;
 
-import static org.junit.Assert.*;
 
+/***
+ * empty test
+ */
 public class SagaApplicationTest {
   @Test
   public void mainTest() {

saga/src/test/java/com/iluwatar/saga/choreography/SagaChoreographyTest.java

@@ -25,13 +25,16 @@ package com.iluwatar.saga.choreography;
 import org.junit.Assert;
 import org.junit.Test;
 
+/**
+ * test to check choreography saga
+ */
 public class SagaChoreographyTest {
 
 
   @Test
   public void executeTest() {
     ServiceDiscoveryService sd = serviceDiscovery();
-        Chapter service = sd.findAny();
+    ChoreographyChapter service = sd.findAny();
     Saga badOrderSaga = service.execute(newSaga("bad_order"));
     Saga goodOrderSaga = service.execute(newSaga("good_order"));
 

saga/src/test/java/com/iluwatar/saga/orchestration/SagaApplicationTest.java

@@ -26,6 +26,9 @@ import org.junit.Test;
 
 import static org.junit.Assert.*;
 
+/**
+ * empty test
+ */
 public class SagaApplicationTest {
 
   @Test

saga/src/test/java/com/iluwatar/saga/orchestration/SagaOrchestratorInternallyTest.java

@@ -28,6 +28,9 @@ import org.junit.Test;
 import java.util.ArrayList;
 import java.util.List;
 
+/**
+ * test to test orchestration logic
+ */
 public class SagaOrchestratorInternallyTest {
 
   private List<String> records = new ArrayList<>();
@@ -86,6 +89,7 @@ public class SagaOrchestratorInternallyTest {
     public String getName() {
       return "2";
     }
+
     @Override
     public ChapterResult<Integer> process(Integer value) {
       records.add("+2");
@@ -105,6 +109,7 @@ public class SagaOrchestratorInternallyTest {
     public String getName() {
       return "3";
     }
+
     @Override
     public ChapterResult<Integer> process(Integer value) {
       records.add("+3");
@@ -124,6 +129,7 @@ public class SagaOrchestratorInternallyTest {
     public String getName() {
       return "4";
     }
+
     @Override
     public ChapterResult<Integer> process(Integer value) {
       records.add("+4");

saga/src/test/java/com/iluwatar/saga/orchestration/SagaOrchestratorTest.java

@@ -25,6 +25,9 @@ package com.iluwatar.saga.orchestration;
 import org.junit.Assert;
 import org.junit.Test;
 
+/**
+ * test to check general logic
+ */
 public class SagaOrchestratorTest {
 
   @Test