[Java] Add inner class Builder to build call options. (#4956)

* Add Builder class

* format

* Refactor by IDE

* Remove uncessary dependency

java/api/src/main/java/org/ray/api/options/ActorCreationOptions.java

@@ -1,5 +1,6 @@
 package org.ray.api.options;
 
+import java.util.HashMap;
 import java.util.Map;
 
 /**
@@ -12,19 +13,32 @@ public class ActorCreationOptions extends BaseTaskOptions {
 
   public final int maxReconstructions;
 
-  public ActorCreationOptions() {
-    super();
-    this.maxReconstructions = NO_RECONSTRUCTION;
-  }
-
-  public ActorCreationOptions(Map<String, Double> resources) {
-    super(resources);
-    this.maxReconstructions = NO_RECONSTRUCTION;
-  }
-
-
-  public ActorCreationOptions(Map<String, Double> resources, int maxReconstructions) {
+  private ActorCreationOptions(Map<String, Double> resources, int maxReconstructions) {
     super(resources);
     this.maxReconstructions = maxReconstructions;
   }
+
+  /**
+   *  The inner class for building ActorCreationOptions.
+   */
+  public static class Builder {
+
+    private Map<String, Double> resources = new HashMap<>();
+    private int maxReconstructions = NO_RECONSTRUCTION;
+
+    public Builder setResources(Map<String, Double> resources) {
+      this.resources = resources;
+      return this;
+    }
+
+    public Builder setMaxReconstructions(int maxReconstructions) {
+      this.maxReconstructions = maxReconstructions;
+      return this;
+    }
+
+    public ActorCreationOptions createActorCreationOptions() {
+      return new ActorCreationOptions(resources, maxReconstructions);
+    }
+  }
+
 }

java/api/src/main/java/org/ray/api/options/CallOptions.java

@@ -1,5 +1,6 @@
 package org.ray.api.options;
 
+import java.util.HashMap;
 import java.util.Map;
 
 /**
@@ -7,12 +8,24 @@ import java.util.Map;
  */
 public class CallOptions extends BaseTaskOptions {
 
-  public CallOptions() {
-    super();
-  }
-
-  public CallOptions(Map<String, Double> resources) {
+  private CallOptions(Map<String, Double> resources) {
     super(resources);
   }
 
+  /**
+   * This inner class for building CallOptions.
+   */
+  public static class Builder {
+
+    private Map<String, Double> resources = new HashMap<>();
+
+    public Builder setResources(Map<String, Double> resources) {
+      this.resources = resources;
+      return this;
+    }
+
+    public CallOptions createCallOptions() {
+      return new CallOptions(resources);
+    }
+  }
 }

java/test/src/main/java/org/ray/api/test/ActorReconstructionTest.java

@@ -3,7 +3,6 @@ package org.ray.api.test;
 import static org.ray.runtime.util.SystemUtil.pid;
 
 import java.io.IOException;
-import java.util.HashMap;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 import org.ray.api.Checkpointable;
@@ -47,7 +46,8 @@ public class ActorReconstructionTest extends BaseTest {
   @Test
   public void testActorReconstruction() throws InterruptedException, IOException {
     TestUtils.skipTestUnderSingleProcess();
-    ActorCreationOptions options = new ActorCreationOptions(new HashMap<>(), 1);
+    ActorCreationOptions options =
+        new ActorCreationOptions.Builder().setMaxReconstructions(1).createActorCreationOptions();
     RayActor<Counter> actor = Ray.createActor(Counter::new, options);
     // Call increase 3 times.
     for (int i = 0; i < 3; i++) {
@@ -127,8 +127,8 @@ public class ActorReconstructionTest extends BaseTest {
   @Test
   public void testActorCheckpointing() throws IOException, InterruptedException {
     TestUtils.skipTestUnderSingleProcess();
-
-    ActorCreationOptions options = new ActorCreationOptions(new HashMap<>(), 1);
+    ActorCreationOptions options =
+        new ActorCreationOptions.Builder().setMaxReconstructions(1).createActorCreationOptions();
     RayActor<CheckpointableCounter> actor = Ray.createActor(CheckpointableCounter::new, options);
     // Call increase 3 times.
     for (int i = 0; i < 3; i++) {

java/test/src/main/java/org/ray/api/test/DynamicResourceTest.java

@@ -23,7 +23,8 @@ public class DynamicResourceTest extends BaseTest {
   @Test
   public void testSetResource() {
     TestUtils.skipTestUnderSingleProcess();
-    CallOptions op1 = new CallOptions(ImmutableMap.of("A", 10.0));
+    CallOptions op1 =
+        new CallOptions.Builder().setResources(ImmutableMap.of("A", 10.0)).createCallOptions();
     RayObject<String> obj = Ray.call(DynamicResourceTest::sayHi, op1);
     WaitResult<String> result = Ray.wait(ImmutableList.of(obj), 1, 1000);
     Assert.assertEquals(result.getReady().size(), 0);

java/test/src/main/java/org/ray/api/test/HelloWorldTest.java

@@ -33,4 +33,5 @@ public class HelloWorldTest extends BaseTest {
     String helloWorld = Ray.call(HelloWorldTest::merge, hello, world).get();
     Assert.assertEquals("hello,world!", helloWorld);
   }
+
 }

java/test/src/main/java/org/ray/api/test/ResourcesManagementTest.java

@@ -46,14 +46,16 @@ public class ResourcesManagementTest extends BaseTest {
   @Test
   public void testMethods() {
     TestUtils.skipTestUnderSingleProcess();
-    CallOptions callOptions1 = new CallOptions(ImmutableMap.of("CPU", 4.0));
+    CallOptions callOptions1 =
+        new CallOptions.Builder().setResources(ImmutableMap.of("CPU", 4.0)).createCallOptions();
 
     // This is a case that can satisfy required resources.
     // The static resources for test are "CPU:4,RES-A:4".
     RayObject<Integer> result1 = Ray.call(ResourcesManagementTest::echo, 100, callOptions1);
     Assert.assertEquals(100, (int) result1.get());
 
-    CallOptions callOptions2 = new CallOptions(ImmutableMap.of("CPU", 4.0));
+    CallOptions callOptions2 =
+        new CallOptions.Builder().setResources(ImmutableMap.of("CPU", 4.0)).createCallOptions();
 
     // This is a case that can't satisfy required resources.
     // The static resources for test are "CPU:4,RES-A:4".
@@ -64,7 +66,8 @@ public class ResourcesManagementTest extends BaseTest {
     Assert.assertEquals(0, waitResult.getUnready().size());
 
     try {
-      CallOptions callOptions3 = new CallOptions(ImmutableMap.of("CPU", 0.0));
+      CallOptions callOptions3 =
+          new CallOptions.Builder().setResources(ImmutableMap.of("CPU", 0.0)).createCallOptions();
       Assert.fail();
     } catch (RuntimeException e) {
       // We should receive a RuntimeException indicates that we should not
@@ -76,9 +79,8 @@ public class ResourcesManagementTest extends BaseTest {
   public void testActors() {
     TestUtils.skipTestUnderSingleProcess();
 
-    ActorCreationOptions actorCreationOptions1 =
-        new ActorCreationOptions(ImmutableMap.of("CPU", 2.0));
-
+    ActorCreationOptions actorCreationOptions1 = new ActorCreationOptions.Builder()
+        .setResources(ImmutableMap.of("CPU", 2.0)).createActorCreationOptions();
     // This is a case that can satisfy required resources.
     // The static resources for test are "CPU:4,RES-A:4".
     RayActor<Echo> echo1 = Ray.createActor(Echo::new, actorCreationOptions1);
@@ -87,8 +89,8 @@ public class ResourcesManagementTest extends BaseTest {
 
     // This is a case that can't satisfy required resources.
     // The static resources for test are "CPU:4,RES-A:4".
-    ActorCreationOptions actorCreationOptions2 =
-        new ActorCreationOptions(ImmutableMap.of("CPU", 8.0));
+    ActorCreationOptions actorCreationOptions2 = new ActorCreationOptions.Builder()
+        .setResources(ImmutableMap.of("CPU", 8.0)).createActorCreationOptions();
 
     RayActor<ResourcesManagementTest.Echo> echo2 =
         Ray.createActor(Echo::new, actorCreationOptions2);