[Java]Fix testSetResource bug (#11064)

Co-authored-by: 灵洵 <fengbin.ffb@antfin.com>

java/test/src/main/java/io/ray/test/DynamicResourceTest.java

@@ -20,19 +20,23 @@ public void testSetResource() {
     // Call a task in advance to warm up the cluster to avoid being too slow to start workers.
     TestUtils.warmUpCluster();
 
+    String resourceName = "A";
     ObjectRef<String> obj = Ray.task(DynamicResourceTest::sayHi)
-        .setResource("A", 10.0)
+        .setResource(resourceName, 10.0)
         .remote();
     WaitResult<String> result = Ray.wait(ImmutableList.of(obj), 1, 1000);
     Assert.assertEquals(result.getReady().size(), 0);
 
-    Ray.setResource("A", 10.0);
+    Ray.setResource(resourceName, 10.0);
     boolean resourceReady = TestUtils.waitForCondition(() -> {
       List<NodeInfo> nodes = Ray.getRuntimeContext().getAllNodeInfo();
-      if (nodes.size() != 1) {
+      // NOTE: GCS updates node resources asynchronously.
+      // If we directly get the value of "A" for comparison without check whether "A" exists or not,
+      // it maybe lead to NPE.
+      if (nodes.size() != 1 || !nodes.get(0).resources.containsKey(resourceName)) {
         return false;
       }
-      return (0 == Double.compare(10.0, nodes.get(0).resources.get("A")));
+      return (0 == Double.compare(10.0, nodes.get(0).resources.get(resourceName)));
     }, 2000);
 
     Assert.assertTrue(resourceReady);