Improve UT grammar and remove unnecessary braces. (apache#2930)

* Improve UT grammer, fix compiler warnings.

* Remove unnecessary braces.

Author: ralf0131

dubbo-cluster/src/main/java/org/apache/dubbo/rpc/cluster/support/AbstractClusterInvoker.java

@@ -121,18 +121,18 @@ protected Invoker<T> select(LoadBalance loadbalance, Invocation invocation,
 
         boolean sticky = invokers.get(0).getUrl()
             .getMethodParameter(methodName, Constants.CLUSTER_STICKY_KEY, Constants.DEFAULT_CLUSTER_STICKY);
-        {
-            //ignore overloaded method
-            if (stickyInvoker != null && !invokers.contains(stickyInvoker)) {
-                stickyInvoker = null;
-            }
-            //ignore concurrency problem
-            if (sticky && stickyInvoker != null && (selected == null || !selected.contains(stickyInvoker))) {
-                if (availablecheck && stickyInvoker.isAvailable()) {
-                    return stickyInvoker;
-                }
+
+        //ignore overloaded method
+        if (stickyInvoker != null && !invokers.contains(stickyInvoker)) {
+            stickyInvoker = null;
+        }
+        //ignore concurrency problem
+        if (sticky && stickyInvoker != null && (selected == null || !selected.contains(stickyInvoker))) {
+            if (availablecheck && stickyInvoker.isAvailable()) {
+                return stickyInvoker;
             }
         }
+
         Invoker<T> invoker = doSelect(loadbalance, invocation, invokers, selected);
 
         if (sticky) {
@@ -210,19 +210,18 @@ private Invoker<T> reselect(LoadBalance loadbalance, Invocation invocation,
         }
 
         // Just pick an available invoker using loadbalance policy
-        {
-            if (selected != null) {
-                for (Invoker<T> invoker : selected) {
-                    if ((invoker.isAvailable()) // available first
-                            && !reselectInvokers.contains(invoker)) {
-                        reselectInvokers.add(invoker);
-                    }
+        if (selected != null) {
+            for (Invoker<T> invoker : selected) {
+                if ((invoker.isAvailable()) // available first
+                        && !reselectInvokers.contains(invoker)) {
+                    reselectInvokers.add(invoker);
                 }
             }
-            if (!reselectInvokers.isEmpty()) {
-                return loadbalance.select(reselectInvokers, getUrl(), invocation);
-            }
         }
+        if (!reselectInvokers.isEmpty()) {
+            return loadbalance.select(reselectInvokers, getUrl(), invocation);
+        }
+
         return null;
     }
 

dubbo-cluster/src/test/java/org/apache/dubbo/rpc/cluster/directory/StaticDirectoryTest.java

@@ -54,12 +54,12 @@ public void testStaticDirectory() {
         invokers.add(invoker2);
         invokers.add(invoker3);
         List<Invoker<String>> filteredInvokers = router.route(invokers, URL.valueOf("consumer://" + NetUtils.getLocalHost() + "/com.foo.BarService"), new RpcInvocation());
-        StaticDirectory staticDirectory = new StaticDirectory(filteredInvokers);
-        Boolean isAvailable = staticDirectory.isAvailable();
+        StaticDirectory<String> staticDirectory = new StaticDirectory<>(filteredInvokers);
+        boolean isAvailable = staticDirectory.isAvailable();
         Assert.assertTrue(!isAvailable);
-        List<Invoker> newInvokers = staticDirectory.list(new MockDirInvocation());
+        List<Invoker<String>> newInvokers = staticDirectory.list(new MockDirInvocation());
         Assert.assertTrue(newInvokers.size() > 0);
         staticDirectory.destroy();
-        Assert.assertTrue(newInvokers.size() == 0);
+        Assert.assertEquals(0, newInvokers.size());
     }
 }