Merge pull request #3143 from beiwei30:prefix, fix prefix, use hypher…

… case instead of camel case.

dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/AbstractConfig.java

@@ -140,7 +140,7 @@ private static String getTagName(Class<?> cls) {
                 break;
             }
         }
-        return tag.substring(0, 1).toLowerCase() + tag.substring(1);
+        return StringUtils.camelToSplitName(tag, "-");
     }
 
     protected static void appendParameters(Map<String, String> parameters, Object config) {

dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ServiceConfig.java

@@ -803,7 +803,7 @@ private void checkProtocol() {
             }
             protocolConfig.refresh();
             if (StringUtils.isNotEmpty(protocolConfig.getId())) {
-                protocolConfig.setPrefix("dubbo.protocols.");
+                protocolConfig.setPrefix(Constants.PROTOCOLS_SUFFIX);
                 protocolConfig.refresh();
             }
         }

dubbo-config/dubbo-config-api/src/test/java/org/apache/dubbo/config/ConfigCenterConfigTest.java

@@ -0,0 +1,31 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.dubbo.config;
+
+import junit.framework.TestCase;
+import org.junit.Test;
+
+public class ConfigCenterConfigTest {
+    @Test
+    public void testPrefix() {
+        ConfigCenterConfig config = new ConfigCenterConfig();
+        TestCase.assertEquals("dubbo.config-center", config.getPrefix());
+    }
+}