Cross language serialization for primitive types (#7711)

* Cross language serialization for Java and Python

* Use strict types when Python serializing

* Handle recursive objects in Python; Pin msgpack >= 0.6.0, < 1.0.0

* Disable gc for optimizing msgpack loads

* Fix merge bug

* Java call Python use returnType; Fix ClassLoaderTest

* Fix RayMethodsTest

* Fix checkstyle

* Fix lint

* prepare_args raises exception if try to transfer a non-deserializable object to another language

* Fix CrossLanguageInvocationTest.java, Python msgpack treat float as double

* Minor fixes

* Fix compile error on linux

* Fix lint in java/BUILD.bazel

* Fix test_failure

* Fix lint

* Class<?> to Class<T>; Refine metadata bytes.

* Rename FST to Fst; sort java dependencies

* Change Class<?>[] to Optional<Class<?>>; sort requirements in setup.py

* Improve CrossLanguageInvocationTest

* Refactor MessagePackSerializer.java

* Refactor MessagePackSerializer.java; Refine CrossLanguageInvocationTest.java

* Remove unnecessary dependencies for Java; Add getReturnType() for RayFunction in Java

* Fix bug

* Remove custom cross language type support

* Replace Serializer.Meta with MutableBoolean

* Remove @SuppressWarnings support from checkstyle.xml; Add null test in CrossLanguageInvocationTest.java

* Refine MessagePackSerializer.pack

* Ray.get support RayObject as input

* Improve comments and error info

* Remove classLoader argument from serializer

* Separate msgpack from pickle5 in Python

* Pair<byte[], MutableBoolean> to Pair<byte[], Boolean>

* Remove public static <T> T get(RayObject<T> object), use RayObject.get() instead

* Refine test

* small fixes

Co-authored-by: 刘宝 <po.lb@antfin.com>
Co-authored-by: Hao Chen <chenh1024@gmail.com>

java/api/src/main/java/org/ray/api/Ray.java

@@ -1,5 +1,6 @@
 package org.ray.api;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.Callable;
 import org.ray.api.id.ObjectId;
@@ -62,23 +63,41 @@ public final class Ray extends RayCall {
   }
 
   /**
-   * Get an object from the object store.
+   * Get an object by id from the object store.
    *
    * @param objectId The ID of the object to get.
+   * @param objectType The type of the object to get.
    * @return The Java object.
    */
-  public static <T> T get(ObjectId objectId) {
-    return runtime.get(objectId);
+  public static <T> T get(ObjectId objectId, Class<T> objectType) {
+    return runtime.get(objectId, objectType);
   }
 
   /**
-   * Get a list of objects from the object store.
+   * Get a list of objects by ids from the object store.
    *
    * @param objectIds The list of object IDs.
+   * @param objectType The type of object.
    * @return A list of Java objects.
    */
-  public static <T> List<T> get(List<ObjectId> objectIds) {
-    return runtime.get(objectIds);
+  public static <T> List<T> get(List<ObjectId> objectIds, Class<T> objectType) {
+    return runtime.get(objectIds, objectType);
+  }
+
+  /**
+   * Get a list of objects by RayObjects from the object store.
+   *
+   * @param objectList A list of RayObject to get.
+   * @return A list of Java objects.
+   */
+  public static <T> List<T> get(List<RayObject<T>> objectList) {
+    List<ObjectId> objectIds = new ArrayList<>();
+    Class<T> objectType = null;
+    for (RayObject<T> o : objectList) {
+      objectIds.add(o.getId());
+      objectType = o.getType();
+    }
+    return runtime.get(objectIds, objectType);
   }
 
   /**

java/api/src/main/java/org/ray/api/RayObject.java

@@ -19,5 +19,10 @@ public interface RayObject<T> {
    */
   ObjectId getId();
 
+  /**
+   * Get the Object type.
+   */
+  Class<T> getType();
+
 }
 

java/api/src/main/java/org/ray/api/runtime/RayRuntime.java

@@ -39,17 +39,19 @@ public interface RayRuntime {
    * Get an object from the object store.
    *
    * @param objectId The ID of the object to get.
+   * @param objectType The type of the object to get.
    * @return The Java object.
    */
-  <T> T get(ObjectId objectId);
+  <T> T get(ObjectId objectId, Class<T> objectType);
 
   /**
    * Get a list of objects from the object store.
    *
    * @param objectIds The list of object IDs.
+   * @param objectType The type of object.
    * @return A list of Java objects.
    */
-  <T> List<T> get(List<ObjectId> objectIds);
+  <T> List<T> get(List<ObjectId> objectIds, Class<T> objectType);
 
   /**
    * Wait for a list of RayObjects to be locally available, until specified number of objects are