diff --git a/dubbo-common/src/main/java/org/apache/dubbo/common/Constants.java b/dubbo-common/src/main/java/org/apache/dubbo/common/Constants.java
index 71cc04dba9f..f799358afe3 100644
--- a/dubbo-common/src/main/java/org/apache/dubbo/common/Constants.java
+++ b/dubbo-common/src/main/java/org/apache/dubbo/common/Constants.java
@@ -231,6 +231,8 @@ public class Constants {
 
     public static final String DOBBO_PROTOCOL = DUBBO;
 
+    public static final String ZOOKEEPER_PROTOCOL = "zookeeper";
+
     public static final String PROXY_KEY = "proxy";
 
     public static final String WEIGHT_KEY = "weight";
@@ -324,6 +326,8 @@ public class Constants {
 
     public static final String EXCHANGER_KEY = "exchanger";
 
+    public static final String DISPACTHER_KEY = "dispacther";
+
     public static final String TRANSPORTER_KEY = "transporter";
 
     public static final String SERVER_KEY = "server";
@@ -769,6 +773,46 @@ public class Constants {
     public static final String[] DEFAULT_REGISTER_CONSUMER_KEYS = {APPLICATION_KEY, VERSION_KEY, GROUP_KEY, DUBBO_VERSION_KEY, SPECIFICATION_VERSION_KEY};
 
     public static final String TELNET = "telnet";
+
+    /**
+     * Application name;
+     */
+    public static final String NAME = "name";
+
+    /**
+     * Application owner name;
+     */
+    public static final String OWNER = "owner";
+
+    /**
+     * Running application organization name.
+     */
+    public static final String ORGANIZATION = "organization";
+
+    /**
+     * Application architecture name.
+     */
+    public static final String ARCHITECTURE = "architecture";
+
+    /**
+     * Environment name
+     */
+    public static final String ENVIRONMENT = "environment";
+
+    /**
+     * Test environment key.
+     */
+    public static final String TEST_ENVIRONMENT = "test";
+
+    /**
+     * Development environment key.
+     */
+    public static final String DEVELOPMENT_ENVIRONMENT = "develop";
+
+    /**
+     * Production environment key.
+     */
+    public static final String PRODUCTION_ENVIRONMENT = "product";
     /*
      * private Constants(){ }
      */
diff --git a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/AbstractServiceConfig.java b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/AbstractServiceConfig.java
index 2f3311b546a..191fcf8c454 100644
--- a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/AbstractServiceConfig.java
+++ b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/AbstractServiceConfig.java
@@ -79,7 +79,7 @@ public String getVersion() {
     }
 
     public void setVersion(String version) {
-        checkKey("version", version);
+        checkKey(Constants.VERSION_KEY, version);
         this.version = version;
     }
 
@@ -88,7 +88,7 @@ public String getGroup() {
     }
 
     public void setGroup(String group) {
-        checkKey("group", group);
+        checkKey(Constants.GROUP_KEY, group);
         this.group = group;
     }
 
@@ -138,7 +138,7 @@ public void setToken(Boolean token) {
     }
 
     public void setToken(String token) {
-        checkName("token", token);
+        checkName(Constants.TOKEN_KEY, token);
         this.token = token;
     }
 
diff --git a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ApplicationConfig.java b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ApplicationConfig.java
index a5c29dbf30a..6b1f53181eb 100644
--- a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ApplicationConfig.java
+++ b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ApplicationConfig.java
@@ -102,9 +102,9 @@ public String getName() {
     }
 
     public void setName(String name) {
-        checkName("name", name);
+        checkName(Constants.NAME, name);
         this.name = name;
-        if (id == null || id.length() == 0) {
+        if (StringUtils.isEmpty(id)) {
             id = name;
         }
     }
@@ -123,7 +123,7 @@ public String getOwner() {
     }
 
     public void setOwner(String owner) {
-        checkMultiName("owner", owner);
+        checkMultiName(Constants.OWNER, owner);
         this.owner = owner;
     }
 
@@ -132,7 +132,7 @@ public String getOrganization() {
     }
 
     public void setOrganization(String organization) {
-        checkName("organization", organization);
+        checkName(Constants.ORGANIZATION, organization);
         this.organization = organization;
     }
 
@@ -141,7 +141,7 @@ public String getArchitecture() {
     }
 
     public void setArchitecture(String architecture) {
-        checkName("architecture", architecture);
+        checkName(Constants.ARCHITECTURE, architecture);
         this.architecture = architecture;
     }
 
@@ -150,10 +150,18 @@ public String getEnvironment() {
     }
 
     public void setEnvironment(String environment) {
-        checkName("environment", environment);
+        checkName(Constants.ENVIRONMENT, environment);
         if (environment != null) {
-            if (!("develop".equals(environment) || "test".equals(environment) || "product".equals(environment))) {
-                throw new IllegalStateException("Unsupported environment: " + environment + ", only support develop/test/product, default is product.");
+            if (!(Constants.DEVELOPMENT_ENVIRONMENT.equals(environment)
+                    || Constants.TEST_ENVIRONMENT.equals(environment)
+                    || Constants.PRODUCTION_ENVIRONMENT.equals(environment))) {
+
+                throw new IllegalStateException(String.format("Unsupported environment: %s, only support %s/%s/%s, default is %s.",
+                        environment,
+                        Constants.DEVELOPMENT_ENVIRONMENT,
+                        Constants.TEST_ENVIRONMENT,
+                        Constants.PRODUCTION_ENVIRONMENT,
+                        Constants.PRODUCTION_ENVIRONMENT));
             }
         }
         this.environment = environment;
@@ -284,4 +292,5 @@ public void setShutwait(String shutwait) {
     public boolean isValid() {
         return !StringUtils.isEmpty(name);
     }
+
 }
\ No newline at end of file
diff --git a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ConfigCenterConfig.java b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ConfigCenterConfig.java
index fe62fda18bf..84e7fddd302 100644
--- a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ConfigCenterConfig.java
+++ b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ConfigCenterConfig.java
@@ -115,7 +115,7 @@ private URL toConfigUrl() {
         map.put(Constants.PATH_KEY, ConfigCenterConfig.class.getSimpleName());
         // use 'zookeeper' as the default configcenter.
         if (StringUtils.isEmpty(map.get(Constants.PROTOCOL_KEY))) {
-            map.put(Constants.PROTOCOL_KEY, "zookeeper");
+            map.put(Constants.PROTOCOL_KEY, Constants.ZOOKEEPER_PROTOCOL);
         }
         return UrlUtils.parseURL(address, map);
     }
diff --git a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/MethodConfig.java b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/MethodConfig.java
index 48045d4261c..50ac47dd6f2 100644
--- a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/MethodConfig.java
+++ b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/MethodConfig.java
@@ -89,7 +89,7 @@ public String getName() {
     public void setName(String name) {
         checkMethodName("name", name);
         this.name = name;
-        if (id == null || id.length() == 0) {
+        if (StringUtils.isEmpty(id)) {
             id = name;
         }
     }
diff --git a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ModuleConfig.java b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ModuleConfig.java
index 0f1501870d2..f07638fe61b 100644
--- a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ModuleConfig.java
+++ b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ModuleConfig.java
@@ -16,6 +16,7 @@
  */
 package org.apache.dubbo.config;
 
+import org.apache.dubbo.common.Constants;
 import org.apache.dubbo.config.support.Parameter;
 
 import java.util.ArrayList;
@@ -64,7 +65,7 @@ public String getName() {
     }
 
     public void setName(String name) {
-        checkName("name", name);
+        checkName(Constants.NAME, name);
         this.name = name;
         if (id == null || id.length() == 0) {
             id = name;
@@ -85,7 +86,7 @@ public String getOwner() {
     }
 
     public void setOwner(String owner) {
-        checkName("owner", owner);
+        checkName(Constants.OWNER, owner);
         this.owner = owner;
     }
 
@@ -94,7 +95,7 @@ public String getOrganization() {
     }
 
     public void setOrganization(String organization) {
-        checkName("organization", organization);
+        checkName(Constants.ORGANIZATION, organization);
         this.organization = organization;
     }
 
diff --git a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ProtocolConfig.java b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ProtocolConfig.java
index 7313f59b699..1f6bc3c7b54 100644
--- a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ProtocolConfig.java
+++ b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ProtocolConfig.java
@@ -16,6 +16,7 @@
  */
 package org.apache.dubbo.config;
 
+import org.apache.dubbo.common.Constants;
 import org.apache.dubbo.common.extension.ExtensionLoader;
 import org.apache.dubbo.common.serialize.Serialization;
 import org.apache.dubbo.common.status.StatusChecker;
@@ -154,7 +155,7 @@ public String getName() {
         return name;
     }
 
-    public void setName(String name) {
+    public final void setName(String name) {
         checkName("name", name);
         this.name = name;
         this.updateIdIfAbsent(name);
@@ -166,7 +167,7 @@ public String getHost() {
     }
 
     public void setHost(String host) {
-        checkName("host", host);
+        checkName(Constants.HOST_KEY, host);
         this.host = host;
     }
 
@@ -175,7 +176,7 @@ public Integer getPort() {
         return port;
     }
 
-    public void setPort(Integer port) {
+    public final void setPort(Integer port) {
         this.port = port;
     }
 
@@ -205,7 +206,7 @@ public String getThreadpool() {
     }
 
     public void setThreadpool(String threadpool) {
-        checkExtension(ThreadPool.class, "threadpool", threadpool);
+        checkExtension(ThreadPool.class, Constants.THREADPOOL_KEY, threadpool);
         this.threadpool = threadpool;
     }
 
@@ -254,8 +255,8 @@ public String getCodec() {
     }
 
     public void setCodec(String codec) {
-        if ("dubbo".equals(name)) {
-            checkMultiExtension(Codec.class, "codec", codec);
+        if (Constants.DOBBO_PROTOCOL.equals(name)) {
+            checkMultiExtension(Codec.class, Constants.CODEC_KEY, codec);
         }
         this.codec = codec;
     }
@@ -265,8 +266,8 @@ public String getSerialization() {
     }
 
     public void setSerialization(String serialization) {
-        if ("dubbo".equals(name)) {
-            checkMultiExtension(Serialization.class, "serialization", serialization);
+        if (Constants.DOBBO_PROTOCOL.equals(name)) {
+            checkMultiExtension(Serialization.class, Constants.SERIALIZATION_KEY, serialization);
         }
         this.serialization = serialization;
     }
@@ -308,8 +309,8 @@ public String getServer() {
     }
 
     public void setServer(String server) {
-        if ("dubbo".equals(name)) {
-            checkMultiExtension(Transporter.class, "server", server);
+        if (Constants.DOBBO_PROTOCOL.equals(name)) {
+            checkMultiExtension(Transporter.class, Constants.SERVER_KEY, server);
         }
         this.server = server;
     }
@@ -319,8 +320,8 @@ public String getClient() {
     }
 
     public void setClient(String client) {
-        if ("dubbo".equals(name)) {
-            checkMultiExtension(Transporter.class, "client", client);
+        if (Constants.DOBBO_PROTOCOL.equals(name)) {
+            checkMultiExtension(Transporter.class, Constants.CLIENT_KEY, client);
         }
         this.client = client;
     }
@@ -338,7 +339,7 @@ public String getTelnet() {
     }
 
     public void setTelnet(String telnet) {
-        checkMultiExtension(TelnetHandler.class, "telnet", telnet);
+        checkMultiExtension(TelnetHandler.class, Constants.TELNET, telnet);
         this.telnet = telnet;
     }
 
@@ -373,7 +374,7 @@ public String getTransporter() {
     }
 
     public void setTransporter(String transporter) {
-        checkExtension(Transporter.class, "transporter", transporter);
+        checkExtension(Transporter.class, Constants.TRANSPORTER_KEY, transporter);
         this.transporter = transporter;
     }
 
@@ -382,7 +383,7 @@ public String getExchanger() {
     }
 
     public void setExchanger(String exchanger) {
-        checkExtension(Exchanger.class, "exchanger", exchanger);
+        checkExtension(Exchanger.class, Constants.EXCHANGER_KEY, exchanger);
         this.exchanger = exchanger;
     }
 
@@ -412,7 +413,7 @@ public String getDispatcher() {
     }
 
     public void setDispatcher(String dispatcher) {
-        checkExtension(Dispatcher.class, "dispacther", dispatcher);
+        checkExtension(Dispatcher.class, Constants.DISPACTHER_KEY, dispatcher);
         this.dispatcher = dispatcher;
     }
 
diff --git a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ProviderConfig.java b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ProviderConfig.java
index 7d69395ad61..aeb4efa43a9 100644
--- a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ProviderConfig.java
+++ b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ProviderConfig.java
@@ -169,7 +169,7 @@ public String getThreadpool() {
     }
 
     public void setThreadpool(String threadpool) {
-        checkExtension(ThreadPool.class, "threadpool", threadpool);
+        checkExtension(ThreadPool.class, Constants.THREADPOOL_KEY, threadpool);
         this.threadpool = threadpool;
     }
 
@@ -258,7 +258,7 @@ public String getTelnet() {
     }
 
     public void setTelnet(String telnet) {
-        checkMultiExtension(TelnetHandler.class, "telnet", telnet);
+        checkMultiExtension(TelnetHandler.class, Constants.TELNET, telnet);
         this.telnet = telnet;
     }
 
@@ -320,7 +320,7 @@ public String getTransporter() {
     }
 
     public void setTransporter(String transporter) {
-        checkExtension(Transporter.class, "transporter", transporter);
+        checkExtension(Transporter.class, Constants.TRANSPORTER_KEY, transporter);
         this.transporter = transporter;
     }
 
@@ -329,7 +329,7 @@ public String getExchanger() {
     }
 
     public void setExchanger(String exchanger) {
-        checkExtension(Exchanger.class, "exchanger", exchanger);
+        checkExtension(Exchanger.class, Constants.EXCHANGER_KEY, exchanger);
         this.exchanger = exchanger;
     }
 
diff --git a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ReferenceConfig.java b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ReferenceConfig.java
index 3c8eb635e78..198f7c3a41c 100644
--- a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ReferenceConfig.java
+++ b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ReferenceConfig.java
@@ -147,34 +147,13 @@ public void checkAndUpdateSubConfigs() {
         }
         resolveFile();
         if (consumer != null) {
-            if (application == null) {
-                application = consumer.getApplication();
-            }
-            if (module == null) {
-                module = consumer.getModule();
-            }
-            if (registries == null) {
-                registries = consumer.getRegistries();
-            }
-            if (monitor == null) {
-                monitor = consumer.getMonitor();
-            }
+            inheritIfAbsentFromConsumer();
         }
         if (module != null) {
-            if (registries == null) {
-                registries = module.getRegistries();
-            }
-            if (monitor == null) {
-                monitor = module.getMonitor();
-            }
+            inheritIfAbsentFromModule();
         }
         if (application != null) {
-            if (registries == null) {
-                registries = application.getRegistries();
-            }
-            if (monitor == null) {
-                monitor = application.getMonitor();
-            }
+            inheritIfAbsentFromApplication();
         }
         checkApplication();
         checkMetadataReport();
@@ -380,6 +359,40 @@ private void checkDefault() {
         consumer.refresh();
     }
 
+    private void inheritIfAbsentFromConsumer() {
+        if (application == null) {
+            application = consumer.getApplication();
+        }
+        if (module == null) {
+            module = consumer.getModule();
+        }
+        if (registries == null) {
+            registries = consumer.getRegistries();
+        }
+        if (monitor == null) {
+            monitor = consumer.getMonitor();
+        }
+    }
+
+    private void inheritIfAbsentFromModule() {
+        if (registries == null) {
+            registries = module.getRegistries();
+        }
+        if (monitor == null) {
+            monitor = module.getMonitor();
+        }
+    }
+
+    private void inheritIfAbsentFromApplication() {
+        if (registries == null) {
+            registries = application.getRegistries();
+        }
+        if (monitor == null) {
+            monitor = application.getMonitor();
+        }
+    }
+
+
     public Class<?> getInterfaceClass() {
         if (interfaceClass != null) {
             return interfaceClass;
diff --git a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/RegistryConfig.java b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/RegistryConfig.java
index 7f15e4c90cf..512fbe8305a 100644
--- a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/RegistryConfig.java
+++ b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/RegistryConfig.java
@@ -120,7 +120,7 @@ public String getProtocol() {
     }
 
     public void setProtocol(String protocol) {
-        checkName("protocol", protocol);
+        checkName(Constants.PROTOCOL_KEY, protocol);
         this.protocol = protocol;
         this.updateIdIfAbsent(protocol);
     }
@@ -232,7 +232,7 @@ public String getTransporter() {
     }
 
     public void setTransporter(String transporter) {
-        checkName("transporter", transporter);
+        checkName(Constants.TRANSPORTER_KEY, transporter);
         /*if(transporter != null && transporter.length() > 0 && ! ExtensionLoader.getExtensionLoader(Transporter.class).hasExtension(transporter)){
             throw new IllegalStateException("No such transporter type : " + transporter);
         }*/
@@ -244,7 +244,7 @@ public String getServer() {
     }
 
     public void setServer(String server) {
-        checkName("server", server);
+        checkName(Constants.SERVER_KEY, server);
         /*if(server != null && server.length() > 0 && ! ExtensionLoader.getExtensionLoader(Transporter.class).hasExtension(server)){
             throw new IllegalStateException("No such server type : " + server);
         }*/
@@ -349,18 +349,8 @@ public boolean isZookeeperProtocol() {
         if (!isValid()) {
             return false;
         }
-        boolean isZookeeper = StringUtils.isNotEmpty(this.getProtocol()) && this.getProtocol().equals("zookeeper");
-        if (!isZookeeper) {
-            String address = this.getAddress();
-            int index = address.indexOf("://");
-            if (StringUtils.isNotEmpty(address) && index >= 0) {
-                address = address.substring(0, index);
-            }
-            if (address.equals("zookeeper")) {
-                isZookeeper = true;
-            }
-        }
-        return isZookeeper;
+        return Constants.ZOOKEEPER_PROTOCOL.equals(getProtocol())
+                || getAddress().startsWith(Constants.ZOOKEEPER_PROTOCOL);
     }
 
     @Override
@@ -369,4 +359,5 @@ public boolean isValid() {
         // empty protocol will default to 'dubbo'
         return !StringUtils.isEmpty(address);
     }
+
 }
diff --git a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ServiceConfig.java b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ServiceConfig.java
index e0f419be789..84b8188cfa8 100644
--- a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ServiceConfig.java
+++ b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ServiceConfig.java
@@ -163,10 +163,7 @@ private static ProviderConfig convertProtocolToProvider(ProtocolConfig protocol)
 
     private static Integer getRandomPort(String protocol) {
         protocol = protocol.toLowerCase();
-        if (RANDOM_PORT_MAP.containsKey(protocol)) {
-            return RANDOM_PORT_MAP.get(protocol);
-        }
-        return Integer.MIN_VALUE;
+        return RANDOM_PORT_MAP.getOrDefault(protocol, Integer.MIN_VALUE);
     }
 
     private static void putRandomPort(String protocol, Integer port) {
@@ -198,37 +195,13 @@ public boolean isUnexported() {
     public void checkAndUpdateSubConfigs() {
         checkDefault();
         if (provider != null) {
-            if (application == null) {
-                application = provider.getApplication();
-            }
-            if (module == null) {
-                module = provider.getModule();
-            }
-            if (registries == null) {
-                registries = provider.getRegistries();
-            }
-            if (monitor == null) {
-                monitor = provider.getMonitor();
-            }
-            if (protocols == null) {
-                protocols = provider.getProtocols();
-            }
+            inheritIfAbsentFromProvider();
         }
         if (module != null) {
-            if (registries == null) {
-                registries = module.getRegistries();
-            }
-            if (monitor == null) {
-                monitor = module.getMonitor();
-            }
+            inheritIfAbsentFromModule();
         }
         if (application != null) {
-            if (registries == null) {
-                registries = application.getRegistries();
-            }
-            if (monitor == null) {
-                monitor = application.getMonitor();
-            }
+            inheritIfAbsentFromApplication();
         }
 
         checkApplication();
@@ -372,7 +345,7 @@ private void doExportUrls() {
     private void doExportUrlsFor1Protocol(ProtocolConfig protocolConfig, List<URL> registryURLs) {
         String name = protocolConfig.getName();
         if (name == null || name.length() == 0) {
-            name = "dubbo";
+            name = Constants.DUBBO;
         }
 
         Map<String, String> map = new HashMap<String, String>();
@@ -553,6 +526,42 @@ private void exportLocal(URL url) {
         }
     }
 
+    private void inheritIfAbsentFromProvider() {
+        if (application == null) {
+            application = provider.getApplication();
+        }
+        if (module == null) {
+            module = provider.getModule();
+        }
+        if (registries == null) {
+            registries = provider.getRegistries();
+        }
+        if (monitor == null) {
+            monitor = provider.getMonitor();
+        }
+        if (protocols == null) {
+            protocols = provider.getProtocols();
+        }
+    }
+
+    private void inheritIfAbsentFromModule() {
+        if (registries == null) {
+            registries = module.getRegistries();
+        }
+        if (monitor == null) {
+            monitor = module.getMonitor();
+        }
+    }
+
+    private void inheritIfAbsentFromApplication() {
+        if (registries == null) {
+            registries = application.getRegistries();
+        }
+        if (monitor == null) {
+            monitor = application.getMonitor();
+        }
+    }
+
     protected Class getServiceClass(T ref) {
         return ref.getClass();
     }