DUBBO-537 必须配地址的注册中心自行检查地址的合法性。

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

@@ -76,6 +76,9 @@ public class MulticastRegistry extends FailbackRegistry {
 
     public MulticastRegistry(URL url) {
         super(url);
+        if (url.isAnyHost()) {
+    		throw new IllegalStateException("registry address == null");
+    	}
         if (! isMulticastAddress(url.getHost())) {
             throw new IllegalArgumentException("Invalid multicast address " + url.getHost() + ", scope: 224.0.0.0 - 239.255.255.255");
         }

dubbo-registry/dubbo-registry-redis/src/main/java/com/alibaba/dubbo/registry/redis/RedisRegistry.java

@@ -82,6 +82,9 @@ public class RedisRegistry extends FailbackRegistry {
 
     public RedisRegistry(URL url) {
         super(url);
+        if (url.isAnyHost()) {
+    		throw new IllegalStateException("registry address == null");
+    	}
         GenericObjectPool.Config config = new GenericObjectPool.Config();
         config.testOnBorrow = url.getParameter("test.on.borrow", true);
         config.testOnReturn = url.getParameter("test.on.return", false);

dubbo-registry/dubbo-registry-zookeeper/src/main/java/com/alibaba/dubbo/registry/zookeeper/ZookeeperRegistry.java

@@ -60,6 +60,9 @@ public class ZookeeperRegistry extends FailbackRegistry {
     
     public ZookeeperRegistry(URL url, ZookeeperTransporter zookeeperTransporter) {
         super(url);
+        if (url.isAnyHost()) {
+    		throw new IllegalStateException("registry address == null");
+    	}
         String group = url.getParameter(Constants.GROUP_KEY, DEFAULT_ROOT);
         if (! group.startsWith(Constants.PATH_SEPARATOR)) {
             group = Constants.PATH_SEPARATOR + group;