Java 11 migrate all remaining s (#1120)

* Moves saga to Java 11

* Moves semaphore to Java 11

* Moves servant to Java 11

* Moves serverless to Java 11

* Moves service-layer to Java 11

* Moves service-locator to Java 11

* Moves sharding to Java 11

* Moves singleton to Java 11

* Moves spatial-partition to Java 11

* Moves specification to Java 11

* Moves state to Java 11

* Moves step-builder to Java 11

* Moves strategy to Java 11

* Moves subclass-sandbox to Java 11

* Fixes checkstyle issues

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

@@ -25,9 +25,9 @@ package com.iluwatar.saga.choreography;
 
 
 /**
- * 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}
+ * 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 ChoreographyChapter {
 
@@ -41,6 +41,7 @@ public interface ChoreographyChapter {
 
   /**
    * get name method.
+   *
    * @return service name.
    */
   String getName();

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

@@ -28,9 +28,8 @@ import java.util.Arrays;
 import java.util.List;
 
 /**
- * Saga representation.
- * Saga consists of chapters.
- * Every ChoreographyChapter is executed a certain service.
+ * Saga representation. Saga consists of chapters. Every ChoreographyChapter is executed a certain
+ * service.
  */
 public class Saga {
 
@@ -61,6 +60,7 @@ public class Saga {
 
   /**
    * add chapter to saga.
+   *
    * @param name chapter name
    * @return this
    */
@@ -71,6 +71,7 @@ public class Saga {
 
   /**
    * set value to last chapter.
+   *
    * @param value invalue
    * @return this
    */
@@ -84,6 +85,7 @@ public class Saga {
 
   /**
    * get value from current chapter.
+   *
    * @return value
    */
   public Object getCurrentValue() {
@@ -92,6 +94,7 @@ public class Saga {
 
   /**
    * set value to current chapter.
+   *
    * @param value to set
    */
   public void setCurrentValue(Object value) {
@@ -100,6 +103,7 @@ public class Saga {
 
   /**
    * set status for current chapter.
+   *
    * @param result to set
    */
   public void setCurrentStatus(ChapterResult result) {
@@ -145,8 +149,8 @@ public class Saga {
   }
 
   /**
-   * Class presents a chapter status and incoming
-   * parameters(incoming parameter transforms to outcoming parameter).
+   * Class presents a chapter status and incoming parameters(incoming parameter transforms to
+   * outcoming parameter).
    */
   public static class Chapter {
     private String name;
@@ -173,6 +177,7 @@ public class Saga {
 
     /**
      * set result.
+     *
      * @param result {@link ChapterResult}
      */
     public void setResult(ChapterResult result) {
@@ -181,6 +186,7 @@ public class Saga {
 
     /**
      * the result for chapter is good.
+     *
      * @return true if is good otherwise bad
      */
     public boolean isSuccess() {

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

@@ -27,22 +27,19 @@ import org.slf4j.Logger;
 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
+ * 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)
+ * If one transaction fails for some reason, the saga executes compensating transactions(rollbacks)
  * to undo the impact of the preceding transactions.
  *
  * <p>In this approach, there are no mediators or orchestrators services.
  * All chapters are handled and moved by services manually.
  *
  * <p>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)
+ * (otherwise in choreography services very hard to prevent a saga if one of them has been crashed)
  *
  * @see com.iluwatar.saga.choreography.Saga
  * @see Service
@@ -54,10 +51,10 @@ public class SagaApplication {
    * main method.
    */
   public static void main(String[] args) {
-    ServiceDiscoveryService sd = serviceDiscovery();
-    ChoreographyChapter service = sd.findAny();
-    Saga goodOrderSaga = service.execute(newSaga("good_order"));
-    Saga badOrderSaga = service.execute(newSaga("bad_order"));
+    var sd = serviceDiscovery();
+    var service = sd.findAny();
+    var goodOrderSaga = service.execute(newSaga("good_order"));
+    var badOrderSaga = service.execute(newSaga("bad_order"));
     LOGGER.info("orders: goodOrder is {}, badOrder is {}",
         goodOrderSaga.getResult(), badOrderSaga.getResult());
 
@@ -74,7 +71,7 @@ public class SagaApplication {
   }
 
   private static ServiceDiscoveryService serviceDiscovery() {
-    ServiceDiscoveryService sd = new ServiceDiscoveryService();
+    var sd = new ServiceDiscoveryService();
     return sd
         .discover(new OrderService(sd))
         .discover(new FlyBookingService(sd))

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

@@ -29,8 +29,8 @@ import org.slf4j.LoggerFactory;
 
 
 /**
- * Common abstraction class representing services.
- * implementing a general contract @see {@link ChoreographyChapter}
+ * Common abstraction class representing services. implementing a general contract @see {@link
+ * ChoreographyChapter}
  */
 public abstract class Service implements ChoreographyChapter {
   protected static final Logger LOGGER = LoggerFactory.getLogger(Service.class);
@@ -43,9 +43,9 @@ public abstract class Service implements ChoreographyChapter {
 
   @Override
   public Saga execute(Saga saga) {
-    Saga nextSaga = saga;
+    var nextSaga = saga;
     Object nextVal;
-    String chapterName = saga.getCurrent().getName();
+    var chapterName = saga.getCurrent().getName();
     if (chapterName.equals(getName())) {
       if (saga.isForward()) {
         nextSaga = process(saga);
@@ -67,7 +67,7 @@ public abstract class Service implements ChoreographyChapter {
 
       nextSaga.setCurrentValue(nextVal);
     }
-    Saga finalNextSaga = nextSaga;
+    var finalNextSaga = nextSaga;
 
     return sd.find(chapterName).map(ch -> ch.execute(finalNextSaga))
         .orElseThrow(serviceNotFoundException(chapterName));
@@ -80,7 +80,7 @@ public abstract class Service implements ChoreographyChapter {
 
   @Override
   public Saga process(Saga saga) {
-    Object inValue = saga.getCurrentValue();
+    var inValue = saga.getCurrentValue();
     LOGGER.info("The chapter '{}' has been started. "
             + "The data {} has been stored or calculated successfully",
         getName(), inValue);
@@ -91,7 +91,7 @@ public abstract class Service implements ChoreographyChapter {
 
   @Override
   public Saga rollback(Saga saga) {
-    Object inValue = saga.getCurrentValue();
+    var inValue = saga.getCurrentValue();
     LOGGER.info("The Rollback for a chapter '{}' has been started. "
             + "The data {} has been rollbacked successfully",
         getName(), inValue);

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

@@ -39,7 +39,7 @@ public class WithdrawMoneyService extends Service {
 
   @Override
   public Saga process(Saga saga) {
-    Object inValue = saga.getCurrentValue();
+    var inValue = saga.getCurrentValue();
 
     if (inValue.equals("bad_order")) {
       LOGGER.info("The chapter '{}' has been started. But the exception has been raised."

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

@@ -32,6 +32,7 @@ public interface OrchestrationChapter<K> {
 
   /**
    * method get name.
+   *
    * @return service name.
    */
   String getName();

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

@@ -27,9 +27,8 @@ import java.util.ArrayList;
 import java.util.List;
 
 /**
- * Saga representation.
- * Saga consists of chapters.
- * Every ChoreographyChapter is executed by a certain service.
+ * Saga representation. Saga consists of chapters. Every ChoreographyChapter is executed by a
+ * certain service.
  */
 public class Saga {
 

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

@@ -27,23 +27,19 @@ import org.slf4j.Logger;
 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
+ * 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)
+ * If one transaction fails for some reason, the saga executes compensating transactions(rollbacks)
  * to undo the impact of the preceding transactions.
  *
  * <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)
+ * 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)
  *
  * @see Saga
  * @see SagaOrchestrator
@@ -56,7 +52,7 @@ public class SagaApplication {
    * method to show common saga logic.
    */
   public static void main(String[] args) {
-    SagaOrchestrator sagaOrchestrator = new SagaOrchestrator(newSaga(), serviceDiscovery());
+    var sagaOrchestrator = new SagaOrchestrator(newSaga(), serviceDiscovery());
 
     Saga.Result goodOrder = sagaOrchestrator.execute("good_order");
     Saga.Result badOrder = sagaOrchestrator.execute("bad_order");
@@ -77,11 +73,10 @@ public class SagaApplication {
   }
 
   private static ServiceDiscoveryService serviceDiscovery() {
-    return
-        new ServiceDiscoveryService()
-            .discover(new OrderService())
-            .discover(new FlyBookingService())
-            .discover(new HotelBookingService())
-            .discover(new WithdrawMoneyService());
+    return new ServiceDiscoveryService()
+        .discover(new OrderService())
+        .discover(new FlyBookingService())
+        .discover(new HotelBookingService())
+        .discover(new WithdrawMoneyService());
   }
 }

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

@@ -23,18 +23,18 @@
 
 package com.iluwatar.saga.orchestration;
 
+import static com.iluwatar.saga.orchestration.Saga.Result;
 import static com.iluwatar.saga.orchestration.Saga.Result.CRASHED;
 import static com.iluwatar.saga.orchestration.Saga.Result.FINISHED;
 import static com.iluwatar.saga.orchestration.Saga.Result.ROLLBACK;
 
-import java.util.Optional;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 
 /**
- * The orchestrator that manages all the transactions and directs
- * the participant services to execute local transactions based on events.
+ * The orchestrator that manages all the transactions and directs the participant services to
+ * execute local transactions based on events.
  */
 public class SagaOrchestrator {
   private static final Logger LOGGER = LoggerFactory.getLogger(SagaOrchestrator.class);
@@ -45,8 +45,9 @@ public class SagaOrchestrator {
 
   /**
    * Create a new service to orchetrate sagas.
+   *
    * @param saga saga to process
-   * @param sd service discovery @see {@link ServiceDiscoveryService}
+   * @param sd   service discovery @see {@link ServiceDiscoveryService}
    */
   public SagaOrchestrator(Saga saga, ServiceDiscoveryService sd) {
     this.saga = saga;
@@ -59,30 +60,30 @@ public class SagaOrchestrator {
    *
    * @param value incoming value
    * @param <K>   type for incoming value
-   * @return result @see {@link Saga.Result}
+   * @return result @see {@link Result}
    */
   @SuppressWarnings("unchecked")
-  public <K> Saga.Result execute(K value) {
+  public <K> Result execute(K value) {
     state.cleanUp();
     LOGGER.info(" The new saga is about to start");
-    Saga.Result result = FINISHED;
+    var result = FINISHED;
     K tempVal = value;
 
     while (true) {
-      int next = state.current();
-      Saga.Chapter ch = saga.get(next);
-      Optional<OrchestrationChapter> srvOpt = sd.find(ch.name);
+      var next = state.current();
+      var ch = saga.get(next);
+      var srvOpt = sd.find(ch.name);
 
-      if (!srvOpt.isPresent()) {
+      if (srvOpt.isEmpty()) {
         state.directionToBack();
         state.back();
         continue;
       }
 
-      OrchestrationChapter srv = srvOpt.get();
+      var srv = srvOpt.get();
 
       if (state.isForward()) {
-        ChapterResult processRes = srv.process(tempVal);
+        var processRes = srv.process(tempVal);
         if (processRes.isSuccess()) {
           next = state.forward();
           tempVal = (K) processRes.getValue();
@@ -90,7 +91,7 @@ public class SagaOrchestrator {
           state.directionToBack();
         }
       } else {
-        ChapterResult rlRes = srv.rollback(tempVal);
+        var rlRes = srv.rollback(tempVal);
         if (rlRes.isSuccess()) {
           next = state.back();
           tempVal = (K) rlRes.getValue();

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

@@ -27,8 +27,8 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Common abstraction class representing services.
- * implementing a general contract @see {@link OrchestrationChapter}
+ * Common abstraction class representing services. implementing a general contract @see {@link
+ * OrchestrationChapter}
  *
  * @param <K> type of incoming param
  */

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

@@ -33,10 +33,10 @@ public class SagaChoreographyTest {
 
   @Test
   public void executeTest() {
-    ServiceDiscoveryService sd = serviceDiscovery();
-    ChoreographyChapter service = sd.findAny();
-    Saga badOrderSaga = service.execute(newSaga("bad_order"));
-    Saga goodOrderSaga = service.execute(newSaga("good_order"));
+    var sd = serviceDiscovery();
+    var service = sd.findAny();
+    var badOrderSaga = service.execute(newSaga("bad_order"));
+    var goodOrderSaga = service.execute(newSaga("good_order"));
 
     Assert.assertEquals(badOrderSaga.getResult(), Saga.SagaResult.ROLLBACKED);
     Assert.assertEquals(goodOrderSaga.getResult(), Saga.SagaResult.FINISHED);
@@ -52,7 +52,7 @@ public class SagaChoreographyTest {
   }
 
   private static ServiceDiscoveryService serviceDiscovery() {
-    ServiceDiscoveryService sd = new ServiceDiscoveryService();
+    var sd = new ServiceDiscoveryService();
     return sd
         .discover(new OrderService(sd))
         .discover(new FlyBookingService(sd))

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

@@ -24,8 +24,6 @@ package com.iluwatar.saga.orchestration;
 
 import org.junit.Test;
 
-import static org.junit.Assert.*;
-
 /**
  * empty test
  */

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

@@ -22,11 +22,12 @@
  */
 package com.iluwatar.saga.orchestration;
 
-import org.junit.Assert;
-import org.junit.Test;
+import static com.iluwatar.saga.orchestration.Saga.Result;
 
 import java.util.ArrayList;
 import java.util.List;
+import org.junit.Assert;
+import org.junit.Test;
 
 /**
  * test to test orchestration logic
@@ -37,17 +38,16 @@ public class SagaOrchestratorInternallyTest {
 
   @Test
   public void executeTest() {
-    SagaOrchestrator sagaOrchestrator = new SagaOrchestrator(newSaga(), serviceDiscovery());
-    Saga.Result result = sagaOrchestrator.execute(1);
-    Assert.assertEquals(result, Saga.Result.ROLLBACK);
+    var sagaOrchestrator = new SagaOrchestrator(newSaga(), serviceDiscovery());
+    var result = sagaOrchestrator.execute(1);
+    Assert.assertEquals(result, Result.ROLLBACK);
     Assert.assertArrayEquals(
         records.toArray(new String[]{}),
         new String[]{"+1", "+2", "+3", "+4", "-4", "-3", "-2", "-1"});
   }
 
   private static Saga newSaga() {
-    return Saga
-        .create()
+    return Saga.create()
         .chapter("1")
         .chapter("2")
         .chapter("3")
@@ -55,12 +55,11 @@ public class SagaOrchestratorInternallyTest {
   }
 
   private ServiceDiscoveryService serviceDiscovery() {
-    return
-        new ServiceDiscoveryService()
-            .discover(new Service1())
-            .discover(new Service2())
-            .discover(new Service3())
-            .discover(new Service4());
+    return new ServiceDiscoveryService()
+        .discover(new Service1())
+        .discover(new Service2())
+        .discover(new Service3())
+        .discover(new Service4());
   }
 
   class Service1 extends Service<Integer> {