[java] when put an object in plasma store, ignore "object alreay exists" exception (#3687)

* distinct plasma client exception

* Update ObjectStoreProxy.java

* Update and rename PlasmaArrowTest.java to PlasmaStoreTest.java

* store put

* Use testng to replace junit to fix test failure

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

@@ -0,0 +1,27 @@
+package org.ray.api.test;
+
+import org.apache.arrow.plasma.PlasmaClient;
+import org.apache.arrow.plasma.exceptions.DuplicateObjectException;
+
+import org.ray.api.Ray;
+import org.ray.api.id.UniqueId;
+import org.ray.runtime.AbstractRayRuntime;
+import org.testng.Assert;
+import org.testng.annotations.Test;
+
+public class PlasmaStoreTest extends BaseTest {
+
+  @Test
+  public void testPutWithDuplicateId() {
+    UniqueId objectId = UniqueId.randomId();
+    AbstractRayRuntime runtime = (AbstractRayRuntime) Ray.internal();
+    PlasmaClient store = new PlasmaClient(runtime.getRayConfig().objectStoreSocketName, "", 0);
+    store.put(objectId.getBytes(), new byte[]{}, new byte[]{});
+    try {
+      store.put(objectId.getBytes(), new byte[]{}, new byte[]{});
+      Assert.fail("This line shouldn't be reached.");
+    } catch (DuplicateObjectException e) {
+      // Putting 2 objects with duplicate ID should throw DuplicateObjectException.
+    }
+  }
+}