Fix#1231

dubbo-cluster/src/main/java/com/alibaba/dubbo/rpc/cluster/support/MergeableClusterInvoker.java

@@ -141,38 +141,27 @@ public Result call() throws Exception {
                         .append(" ]")
                         .toString());
             }
-            if (method != null) {
-                if (!Modifier.isPublic(method.getModifiers())) {
-                    method.setAccessible(true);
-                }
-                result = resultList.remove(0).getValue();
-                try {
-                    if (method.getReturnType() != void.class
-                            && method.getReturnType().isAssignableFrom(result.getClass())) {
-                        for (Result r : resultList) {
-                            result = method.invoke(result, r.getValue());
-                        }
-                    } else {
-                        for (Result r : resultList) {
-                            method.invoke(result, r.getValue());
-                        }
+            if (!Modifier.isPublic(method.getModifiers())) {
+                method.setAccessible(true);
+            }
+            result = resultList.remove(0).getValue();
+            try {
+                if (method.getReturnType() != void.class
+                        && method.getReturnType().isAssignableFrom(result.getClass())) {
+                    for (Result r : resultList) {
+                        result = method.invoke(result, r.getValue());
+                    }
+                } else {
+                    for (Result r : resultList) {
+                        method.invoke(result, r.getValue());
                     }
-                } catch (Exception e) {
-                    throw new RpcException(
-                            new StringBuilder(32)
-                                    .append("Can not merge result: ")
-                                    .append(e.getMessage()).toString(),
-                            e);
                 }
-            } else {
+            } catch (Exception e) {
                 throw new RpcException(
                         new StringBuilder(32)
-                                .append("Can not merge result because missing method [ ")
-                                .append(merger)
-                                .append(" ] in class [ ")
-                                .append(returnType.getClass().getName())
-                                .append(" ]")
-                                .toString());
+                                .append("Can not merge result: ")
+                                .append(e.getMessage()).toString(),
+                        e);
             }
         } else {
             Merger resultMerger;

dubbo-common/src/main/java/com/alibaba/dubbo/common/beanutil/JavaBeanDescriptor.java

@@ -137,7 +137,7 @@ public String setEnumNameProperty(String name) {
 
     public String getEnumPropertyName() {
         if (isEnumType()) {
-            Object result = getProperty(ENUM_PROPERTY_NAME).toString();
+            Object result = getProperty(ENUM_PROPERTY_NAME);
             return result == null ? null : result.toString();
         }
         throw new IllegalStateException("The instance is not a enum wrapper");

dubbo-common/src/main/java/com/alibaba/dubbo/common/extension/ExtensionLoader.java

@@ -330,7 +330,8 @@ public boolean hasExtension(String name) {
         if (name == null || name.length() == 0)
             throw new IllegalArgumentException("Extension name == null");
         try {
-            return getExtensionClass(name) != null;
+            this.getExtensionClass(name);
+            return true;
         } catch (Throwable t) {
             return false;
         }

dubbo-common/src/main/java/com/alibaba/dubbo/common/utils/CollectionUtils.java

@@ -94,7 +94,7 @@ public static Map<String, String> split(List<String> list, String separator) {
             return null;
         }
         Map<String, String> map = new HashMap<String, String>();
-        if (list == null || list.isEmpty()) {
+        if (list.isEmpty()) {
             return map;
         }
         for (String item : list) {
@@ -113,7 +113,7 @@ public static List<String> join(Map<String, String> map, String separator) {
             return null;
         }
         List<String> list = new ArrayList<String>();
-        if (map == null || map.size() == 0) {
+        if (map.size() == 0) {
             return list;
         }
         for (Map.Entry<String, String> entry : map.entrySet()) {

dubbo-config/dubbo-config-api/src/main/java/com/alibaba/dubbo/config/AbstractConfig.java

@@ -268,7 +268,7 @@ && isPrimitive(method.getReturnType())) {
                     if (parameter == null || !parameter.attribute())
                         continue;
                     String key;
-                    if (parameter != null && parameter.key() != null && parameter.key().length() > 0) {
+                    if (parameter.key() != null && parameter.key().length() > 0) {
                         key = parameter.key();
                     } else {
                         int i = name.startsWith("get") ? 3 : 2;

dubbo-registry/dubbo-registry-multicast/src/main/java/com/alibaba/dubbo/registry/multicast/MulticastRegistry.java

@@ -395,13 +395,13 @@ public List<URL> lookup(URL url) {
                 urls.addAll(values);
             }
         }
-        if (urls == null || urls.isEmpty()) {
+        if (urls.isEmpty()) {
             List<URL> cacheUrls = getCacheUrls(url);
             if (cacheUrls != null && !cacheUrls.isEmpty()) {
                 urls.addAll(cacheUrls);
             }
         }
-        if (urls == null || urls.isEmpty()) {
+        if (urls.isEmpty()) {
             for (URL u : getRegistered()) {
                 if (UrlUtils.isMatch(url, u)) {
                     urls.add(u);

dubbo-remoting/dubbo-remoting-api/src/main/java/com/alibaba/dubbo/remoting/telnet/codec/TelnetCodec.java

@@ -260,18 +260,14 @@ protected Object decode(Channel channel, ChannelBuffer buffer, int readable, byt
             String value = history.get(index);
             if (value != null) {
                 byte[] b1 = value.getBytes();
-                if (message != null && message.length > 0) {
-                    byte[] b2 = new byte[b1.length + message.length];
-                    System.arraycopy(b1, 0, b2, 0, b1.length);
-                    System.arraycopy(message, 0, b2, b1.length, message.length);
-                    message = b2;
-                } else {
-                    message = b1;
-                }
+                byte[] b2 = new byte[b1.length + message.length];
+                System.arraycopy(b1, 0, b2, 0, b1.length);
+                System.arraycopy(message, 0, b2, b1.length, message.length);
+                message = b2;
             }
         }
         String result = toString(message, getCharset(channel));
-        if (result != null && result.trim().length() > 0) {
+        if (result.trim().length() > 0) {
             if (history == null) {
                 history = new LinkedList<String>();
                 channel.setAttribute(HISTORY_LIST_KEY, history);

dubbo-rpc/dubbo-rpc-default/src/main/java/com/alibaba/dubbo/rpc/protocol/dubbo/DubboProtocol.java

@@ -91,18 +91,18 @@ public Object reply(ExchangeChannel channel, Object message) throws RemotingExce
                         }
                     }
                     if (!hasMethod) {
-                        logger.warn(new IllegalStateException("The methodName " + inv.getMethodName() 
+                        logger.warn(new IllegalStateException("The methodName " + inv.getMethodName()
                                 + " not found in callback service interface ,invoke will be ignored."
-                                + " please update the api interface. url is:" 
+                                + " please update the api interface. url is:"
                                 + invoker.getUrl()) + " ,invocation is :" + inv);
                         return null;
                     }
                 }
                 RpcContext.getContext().setRemoteAddress(channel.getRemoteAddress());
                 return invoker.invoke(inv);
             }
-            throw new RemotingException(channel, "Unsupported request: " 
-                    + (message == null ? null : (message.getClass().getName() + ": " + message)) 
+            throw new RemotingException(channel, "Unsupported request: "
+                    + (message == null ? null : (message.getClass().getName() + ": " + message))
                     + ", channel: consumer: " + channel.getRemoteAddress() + " --> provider: " + channel.getLocalAddress());
         }
 

dubbo-rpc/dubbo-rpc-default/src/main/java/com/alibaba/dubbo/rpc/protocol/dubbo/filter/FutureFilter.java

@@ -107,7 +107,7 @@ private void fireInvokeCallback(final Invoker<?> invoker, final Invocation invoc
         if (onInvokeMethod == null || onInvokeInst == null) {
             throw new IllegalStateException("service:" + invoker.getUrl().getServiceKey() + " has a onreturn callback config , but no such " + (onInvokeMethod == null ? "method" : "instance") + " found. url:" + invoker.getUrl());
         }
-        if (onInvokeMethod != null && !onInvokeMethod.isAccessible()) {
+        if (!onInvokeMethod.isAccessible()) {
             onInvokeMethod.setAccessible(true);
         }
 
@@ -133,7 +133,7 @@ private void fireReturnCallback(final Invoker<?> invoker, final Invocation invoc
         if (onReturnMethod == null || onReturnInst == null) {
             throw new IllegalStateException("service:" + invoker.getUrl().getServiceKey() + " has a onreturn callback config , but no such " + (onReturnMethod == null ? "method" : "instance") + " found. url:" + invoker.getUrl());
         }
-        if (onReturnMethod != null && !onReturnMethod.isAccessible()) {
+        if (!onReturnMethod.isAccessible()) {
             onReturnMethod.setAccessible(true);
         }
 
@@ -173,7 +173,7 @@ private void fireThrowCallback(final Invoker<?> invoker, final Invocation invoca
         if (onthrowMethod == null || onthrowInst == null) {
             throw new IllegalStateException("service:" + invoker.getUrl().getServiceKey() + " has a onthrow callback config , but no such " + (onthrowMethod == null ? "method" : "instance") + " found. url:" + invoker.getUrl());
         }
-        if (onthrowMethod != null && !onthrowMethod.isAccessible()) {
+        if (!onthrowMethod.isAccessible()) {
             onthrowMethod.setAccessible(true);
         }
         Class<?>[] rParaTypes = onthrowMethod.getParameterTypes();

dubbo-rpc/dubbo-rpc-http/src/main/java/com/alibaba/dubbo/rpc/protocol/http/HttpProtocol.java

@@ -109,7 +109,7 @@ protected void prepareConnection(HttpURLConnection con,
             HttpComponentsHttpInvokerRequestExecutor httpInvokerRequestExecutor = new HttpComponentsHttpInvokerRequestExecutor();
             httpInvokerRequestExecutor.setReadTimeout(url.getParameter(Constants.CONNECT_TIMEOUT_KEY, Constants.DEFAULT_CONNECT_TIMEOUT));
             httpProxyFactoryBean.setHttpInvokerRequestExecutor(httpInvokerRequestExecutor);
-        } else if (client != null && client.length() > 0) {
+        } else {
             throw new IllegalStateException("Unsupported http protocol client " + client + ", only supported: simple, commons");
         }
         httpProxyFactoryBean.afterPropertiesSet();