Merge remote-tracking branch 'apache/master'
diff --git a/java/dubbo-samples-async/dubbo-samples-async-onerror/pom.xml b/java/dubbo-samples-async/dubbo-samples-async-onerror/pom.xml
index 68c49f0..b4f5505 100644
--- a/java/dubbo-samples-async/dubbo-samples-async-onerror/pom.xml
+++ b/java/dubbo-samples-async/dubbo-samples-async-onerror/pom.xml
@@ -32,7 +32,8 @@
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
         <spring.version>4.3.16.RELEASE</spring.version>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.6</dubbo.version>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
         <zookeeper.version>3.4.13</zookeeper.version>
         <curator.version>4.0.1</curator.version>
         <validation-api.version>1.1.0.Final</validation-api.version>
@@ -93,6 +94,11 @@
                 <version>${dubbo.version}</version>
             </dependency>
             <dependency>
+                <groupId>org.apache.dubbo</groupId>
+                <artifactId>dubbo-configcenter-zookeeper</artifactId>
+                <version>${dubbo.configcenter.zookeeper.version}</version>
+            </dependency>
+            <dependency>
                 <groupId>org.apache.zookeeper</groupId>
                 <artifactId>zookeeper</artifactId>
                 <version>${zookeeper.version}</version>
@@ -189,6 +195,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>io.netty</groupId>
diff --git a/java/dubbo-samples-async/dubbo-samples-async-original-future/pom.xml b/java/dubbo-samples-async/dubbo-samples-async-original-future/pom.xml
index ebfe674..5e590fb 100644
--- a/java/dubbo-samples-async/dubbo-samples-async-original-future/pom.xml
+++ b/java/dubbo-samples-async/dubbo-samples-async-original-future/pom.xml
@@ -31,7 +31,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7-SNAPSHOT</dubbo.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>
         <docker-maven-plugin.version>0.30.0</docker-maven-plugin.version>
diff --git a/java/dubbo-samples-cloud-native/dubbo-call-sc/dubbo-sc-consumer/pom.xml b/java/dubbo-samples-cloud-native/dubbo-call-sc/dubbo-sc-consumer/pom.xml
index 5b26513..a67d4ce 100644
--- a/java/dubbo-samples-cloud-native/dubbo-call-sc/dubbo-sc-consumer/pom.xml
+++ b/java/dubbo-samples-cloud-native/dubbo-call-sc/dubbo-sc-consumer/pom.xml
@@ -29,6 +29,7 @@
     <description>The demo consumer module of dubbo project</description>
     <properties>
         <skip_maven_deploy>true</skip_maven_deploy>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
     </properties>
     <dependencies>
         <dependency>
@@ -55,6 +56,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>org.apache.dubbo</groupId>
diff --git a/java/dubbo-samples-cloud-native/dubbo-call-scdubbo/dubbo-scdubbo-consumer/pom.xml b/java/dubbo-samples-cloud-native/dubbo-call-scdubbo/dubbo-scdubbo-consumer/pom.xml
index e87c33a..e40dfec 100644
--- a/java/dubbo-samples-cloud-native/dubbo-call-scdubbo/dubbo-scdubbo-consumer/pom.xml
+++ b/java/dubbo-samples-cloud-native/dubbo-call-scdubbo/dubbo-scdubbo-consumer/pom.xml
@@ -29,6 +29,7 @@
     <description>The demo consumer module of dubbo project</description>
     <properties>
         <skip_maven_deploy>true</skip_maven_deploy>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
     </properties>
     <dependencies>
         <dependency>
@@ -55,6 +56,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>org.apache.dubbo</groupId>
diff --git a/java/dubbo-samples-cloud-native/dubbo-call-scdubbo/dubbo-scdubbo-provider2/pom.xml b/java/dubbo-samples-cloud-native/dubbo-call-scdubbo/dubbo-scdubbo-provider2/pom.xml
index a9a2393..b1bcf24 100644
--- a/java/dubbo-samples-cloud-native/dubbo-call-scdubbo/dubbo-scdubbo-provider2/pom.xml
+++ b/java/dubbo-samples-cloud-native/dubbo-call-scdubbo/dubbo-scdubbo-provider2/pom.xml
@@ -30,6 +30,7 @@
     <properties>
         <skip_maven_deploy>true</skip_maven_deploy>
         <slf4j-log4j12.version>1.7.25</slf4j-log4j12.version>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
     </properties>
 
     <dependencies>
@@ -57,6 +58,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>org.apache.dubbo</groupId>
diff --git a/java/dubbo-samples-cloud-native/dubbo-demo-servicediscovery-xml/servicediscovery-consumer/pom.xml b/java/dubbo-samples-cloud-native/dubbo-demo-servicediscovery-xml/servicediscovery-consumer/pom.xml
index 2a6f5ce..bc520c5 100644
--- a/java/dubbo-samples-cloud-native/dubbo-demo-servicediscovery-xml/servicediscovery-consumer/pom.xml
+++ b/java/dubbo-samples-cloud-native/dubbo-demo-servicediscovery-xml/servicediscovery-consumer/pom.xml
@@ -29,6 +29,7 @@
     <description>The demo consumer module of dubbo project</description>
     <properties>
         <skip_maven_deploy>true</skip_maven_deploy>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
     </properties>
     <dependencies>
         <dependency>
@@ -55,6 +56,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>org.apache.dubbo</groupId>
diff --git a/java/dubbo-samples-cloud-native/dubbo-demo-servicediscovery-xml/servicediscovery-provider/pom.xml b/java/dubbo-samples-cloud-native/dubbo-demo-servicediscovery-xml/servicediscovery-provider/pom.xml
index d9f0ce9..93277e9 100644
--- a/java/dubbo-samples-cloud-native/dubbo-demo-servicediscovery-xml/servicediscovery-provider/pom.xml
+++ b/java/dubbo-samples-cloud-native/dubbo-demo-servicediscovery-xml/servicediscovery-provider/pom.xml
@@ -30,6 +30,7 @@
     <properties>
         <skip_maven_deploy>true</skip_maven_deploy>
         <slf4j-log4j12.version>1.7.25</slf4j-log4j12.version>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
     </properties>
 
     <dependencies>
@@ -57,6 +58,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>org.apache.dubbo</groupId>
diff --git a/java/dubbo-samples-cloud-native/sc-call-dubbo/sc-dubbo-provider/pom.xml b/java/dubbo-samples-cloud-native/sc-call-dubbo/sc-dubbo-provider/pom.xml
index ed95447..9252ab2 100644
--- a/java/dubbo-samples-cloud-native/sc-call-dubbo/sc-dubbo-provider/pom.xml
+++ b/java/dubbo-samples-cloud-native/sc-call-dubbo/sc-dubbo-provider/pom.xml
@@ -31,6 +31,7 @@
     <properties>
         <skip_maven_deploy>true</skip_maven_deploy>
         <slf4j-log4j12.version>1.7.25</slf4j-log4j12.version>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
     </properties>
 
     <artifactId>sc-dubbo-provider</artifactId>
@@ -64,6 +65,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>org.apache.dubbo</groupId>
diff --git a/java/dubbo-samples-cloud-native/servicediscovery-transfer/servicediscovery-transfer-consumer-old/pom.xml b/java/dubbo-samples-cloud-native/servicediscovery-transfer/servicediscovery-transfer-consumer-old/pom.xml
index a406146..872c91e 100644
--- a/java/dubbo-samples-cloud-native/servicediscovery-transfer/servicediscovery-transfer-consumer-old/pom.xml
+++ b/java/dubbo-samples-cloud-native/servicediscovery-transfer/servicediscovery-transfer-consumer-old/pom.xml
@@ -28,6 +28,7 @@
     <description>The demo consumer module of dubbo project</description>
     <properties>
         <skip_maven_deploy>true</skip_maven_deploy>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
     </properties>
     <dependencies>
         <dependency>
@@ -54,6 +55,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>org.apache.dubbo</groupId>
diff --git a/java/dubbo-samples-cloud-native/servicediscovery-transfer/servicediscovery-transfer-consumer/pom.xml b/java/dubbo-samples-cloud-native/servicediscovery-transfer/servicediscovery-transfer-consumer/pom.xml
index a90ad77..501be6b 100644
--- a/java/dubbo-samples-cloud-native/servicediscovery-transfer/servicediscovery-transfer-consumer/pom.xml
+++ b/java/dubbo-samples-cloud-native/servicediscovery-transfer/servicediscovery-transfer-consumer/pom.xml
@@ -29,6 +29,7 @@
     <description>The demo consumer module of dubbo project</description>
     <properties>
         <skip_maven_deploy>true</skip_maven_deploy>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
     </properties>
     <dependencies>
         <dependency>
@@ -55,6 +56,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>org.apache.dubbo</groupId>
diff --git a/java/dubbo-samples-cloud-native/servicediscovery-transfer/servicediscovery-transfer-provider/pom.xml b/java/dubbo-samples-cloud-native/servicediscovery-transfer/servicediscovery-transfer-provider/pom.xml
index 18e8247..a9c7655 100644
--- a/java/dubbo-samples-cloud-native/servicediscovery-transfer/servicediscovery-transfer-provider/pom.xml
+++ b/java/dubbo-samples-cloud-native/servicediscovery-transfer/servicediscovery-transfer-provider/pom.xml
@@ -30,6 +30,7 @@
     <properties>
         <skip_maven_deploy>true</skip_maven_deploy>
         <slf4j-log4j12.version>1.7.25</slf4j-log4j12.version>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
     </properties>
 
     <dependencies>
@@ -57,6 +58,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>org.apache.dubbo</groupId>
diff --git a/java/dubbo-samples-configcenter/dubbo-samples-configcenter-apollo/pom.xml b/java/dubbo-samples-configcenter/dubbo-samples-configcenter-apollo/pom.xml
index c1b5fa3..fa1f441 100644
--- a/java/dubbo-samples-configcenter/dubbo-samples-configcenter-apollo/pom.xml
+++ b/java/dubbo-samples-configcenter/dubbo-samples-configcenter-apollo/pom.xml
@@ -89,6 +89,7 @@
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-test</artifactId>
+            <version>4.3.16.RELEASE</version>
             <scope>test</scope>
         </dependency>
     </dependencies>
diff --git a/java/dubbo-samples-configcenter/dubbo-samples-configcenter-multiprotocol/pom.xml b/java/dubbo-samples-configcenter/dubbo-samples-configcenter-multiprotocol/pom.xml
index f37e1e4..fb58826 100644
--- a/java/dubbo-samples-configcenter/dubbo-samples-configcenter-multiprotocol/pom.xml
+++ b/java/dubbo-samples-configcenter/dubbo-samples-configcenter-multiprotocol/pom.xml
@@ -75,16 +75,19 @@
         <dependency>
             <groupId>com.caucho</groupId>
             <artifactId>hessian</artifactId>
+            <version>4.0.63</version>
         </dependency>
 
         <dependency>
             <groupId>org.eclipse.jetty</groupId>
             <artifactId>jetty-server</artifactId>
+            <version>9.4.11.v20180605</version>
         </dependency>
 
         <dependency>
             <groupId>org.eclipse.jetty</groupId>
             <artifactId>jetty-servlet</artifactId>
+            <version>9.4.11.v20180605</version>
         </dependency>
 
         <dependency>
@@ -97,6 +100,7 @@
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-test</artifactId>
+            <version>4.3.16.RELEASE</version>
             <scope>test</scope>
         </dependency>
     </dependencies>
diff --git a/java/dubbo-samples-gateway/pom.xml b/java/dubbo-samples-gateway/pom.xml
index 73545e2..a8aa7c3 100644
--- a/java/dubbo-samples-gateway/pom.xml
+++ b/java/dubbo-samples-gateway/pom.xml
@@ -13,7 +13,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.6</dubbo.version>
         <junit.version>4.12</junit.version>
         <maven-compiler-plugin.version>3.7.0</maven-compiler-plugin.version>
     </properties>
diff --git a/java/dubbo-samples-http/pom.xml b/java/dubbo-samples-http/pom.xml
index 295fe49..fa577de 100644
--- a/java/dubbo-samples-http/pom.xml
+++ b/java/dubbo-samples-http/pom.xml
@@ -42,6 +42,8 @@
         <servlet.container.1>tomcat</servlet.container.1>
         <servlet.port.2>8081</servlet.port.2>
         <servlet.container.2>jetty</servlet.container.2>
+        <servlet.version>3.0.1</servlet.version>
+        <tomcat.version>7.0.88</tomcat.version>
         <zookeeper.port>2181</zookeeper.port>
         <main-class>org.apache.dubbo.samples.http.HttpProvider</main-class>
     </properties>
@@ -75,26 +77,31 @@
         <dependency>
             <groupId>javax.servlet</groupId>
             <artifactId>javax.servlet-api</artifactId>
+            <version>${servlet.version}</version>
         </dependency>
 
         <dependency>
             <groupId>org.apache.tomcat.embed</groupId>
             <artifactId>tomcat-embed-core</artifactId>
+            <version>${tomcat.version}</version>
         </dependency>
 
         <dependency>
             <groupId>org.eclipse.jetty</groupId>
             <artifactId>jetty-server</artifactId>
+            <version>9.4.11.v20180605</version>
         </dependency>
 
         <dependency>
             <groupId>org.eclipse.jetty</groupId>
             <artifactId>jetty-servlet</artifactId>
+            <version>9.4.11.v20180605</version>
         </dependency>
 
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-web</artifactId>
+            <version>${spring.version}</version>
         </dependency>
 
         <dependency>
diff --git a/java/dubbo-samples-jetty/pom.xml b/java/dubbo-samples-jetty/pom.xml
index 4b410f5..81c52f8 100644
--- a/java/dubbo-samples-jetty/pom.xml
+++ b/java/dubbo-samples-jetty/pom.xml
@@ -34,6 +34,7 @@
     <dubbo.version>2.7.5</dubbo.version>
     <dubbo.rpc.version>2.7.5</dubbo.rpc.version>
     <zookeeper.version>3.4.13</zookeeper.version>
+    <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
     <curator.version>4.0.1</curator.version>
     <validation-api.version>1.1.0.Final</validation-api.version>
     <hibernate-validator.version>4.2.0.Final</hibernate-validator.version>
@@ -192,6 +193,7 @@
     <dependency>
       <groupId>org.apache.dubbo</groupId>
       <artifactId>dubbo-configcenter-zookeeper</artifactId>
+      <version>${dubbo.configcenter.zookeeper.version}</version>
     </dependency>
     <dependency>
       <groupId>io.netty</groupId>
diff --git a/java/dubbo-samples-merge/dubbo-samples-merge-consumer/pom.xml b/java/dubbo-samples-merge/dubbo-samples-merge-consumer/pom.xml
index d64f341..5ac3a6e 100644
--- a/java/dubbo-samples-merge/dubbo-samples-merge-consumer/pom.xml
+++ b/java/dubbo-samples-merge/dubbo-samples-merge-consumer/pom.xml
@@ -29,7 +29,7 @@
     <artifactId>dubbo-samples-merge-consumer</artifactId>
 
     <properties>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7-SNAPSHOT</dubbo.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>
         <maven-failsafe-plugin.version>2.21.0</maven-failsafe-plugin.version>
diff --git a/java/dubbo-samples-merge/dubbo-samples-merge-provider1/pom.xml b/java/dubbo-samples-merge/dubbo-samples-merge-provider1/pom.xml
index 6619552..d19fff5 100644
--- a/java/dubbo-samples-merge/dubbo-samples-merge-provider1/pom.xml
+++ b/java/dubbo-samples-merge/dubbo-samples-merge-provider1/pom.xml
@@ -29,7 +29,7 @@
     <artifactId>dubbo-samples-merge-provider1</artifactId>
 
     <properties>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7-SNAPSHOT</dubbo.version>
         <jib-maven-plugin.version>1.2.0</jib-maven-plugin.version>
         <image.name>${project.artifactId}:${dubbo.version}</image.name>
         <java-image.name>openjdk:8</java-image.name>
diff --git a/java/dubbo-samples-merge/dubbo-samples-merge-provider2/pom.xml b/java/dubbo-samples-merge/dubbo-samples-merge-provider2/pom.xml
index a8a259a..92b92ff 100644
--- a/java/dubbo-samples-merge/dubbo-samples-merge-provider2/pom.xml
+++ b/java/dubbo-samples-merge/dubbo-samples-merge-provider2/pom.xml
@@ -29,7 +29,7 @@
     <artifactId>dubbo-samples-merge-provider2</artifactId>
 
     <properties>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7-SNAPSHOT</dubbo.version>
         <jib-maven-plugin.version>1.2.0</jib-maven-plugin.version>
         <image.name>${project.artifactId}:${dubbo.version}</image.name>
         <java-image.name>openjdk:8</java-image.name>
diff --git a/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-configcenter/pom.xml b/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-configcenter/pom.xml
index 0fdc410..dba859f 100644
--- a/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-configcenter/pom.xml
+++ b/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-configcenter/pom.xml
@@ -30,7 +30,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7-SNAPSHOT</dubbo.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>
         <docker-maven-plugin.version>0.30.0</docker-maven-plugin.version>
diff --git a/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-local-annotation/pom.xml b/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-local-annotation/pom.xml
index 6fd41b6..e4bbcc1 100644
--- a/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-local-annotation/pom.xml
+++ b/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-local-annotation/pom.xml
@@ -30,7 +30,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7-SNAPSHOT</dubbo.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>
         <docker-maven-plugin.version>0.30.0</docker-maven-plugin.version>
diff --git a/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-local-properties/pom.xml b/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-local-properties/pom.xml
index 87d92b9..f898477 100644
--- a/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-local-properties/pom.xml
+++ b/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-local-properties/pom.xml
@@ -30,7 +30,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7-SNAPSHOT</dubbo.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>
         <docker-maven-plugin.version>0.30.0</docker-maven-plugin.version>
diff --git a/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-local-xml/pom.xml b/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-local-xml/pom.xml
index d0f4eec..9185414 100644
--- a/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-local-xml/pom.xml
+++ b/java/dubbo-samples-metadata-report/dubbo-samples-metadata-report-local-xml/pom.xml
@@ -30,7 +30,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7-SNAPSHOT</dubbo.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>
         <docker-maven-plugin.version>0.30.0</docker-maven-plugin.version>
diff --git a/java/dubbo-samples-protobuf/protobuf-consumer/pom.xml b/java/dubbo-samples-protobuf/protobuf-consumer/pom.xml
index b394b90..657662e 100644
--- a/java/dubbo-samples-protobuf/protobuf-consumer/pom.xml
+++ b/java/dubbo-samples-protobuf/protobuf-consumer/pom.xml
@@ -28,6 +28,8 @@
     <description>The demo consumer module of dubbo project</description>
     <properties>
         <skip_maven_deploy>true</skip_maven_deploy>
+        <zookeeper.version>3.4.3</zookeeper.version>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
     </properties>
     <dependencies>
         <dependency>
@@ -65,6 +67,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>org.apache.dubbo</groupId>
diff --git a/java/dubbo-samples-protobuf/protobuf-provider/pom.xml b/java/dubbo-samples-protobuf/protobuf-provider/pom.xml
index 1ac69e6..ed2af29 100644
--- a/java/dubbo-samples-protobuf/protobuf-provider/pom.xml
+++ b/java/dubbo-samples-protobuf/protobuf-provider/pom.xml
@@ -31,6 +31,8 @@
         <spring-test.version>4.3.16.RELEASE</spring-test.version>
         <skip_maven_deploy>true</skip_maven_deploy>
         <slf4j-log4j12.version>1.7.25</slf4j-log4j12.version>
+        <zookeeper.version>3.4.3</zookeeper.version>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
     </properties>
 
     <dependencies>
@@ -65,6 +67,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>org.apache.dubbo</groupId>
diff --git a/java/dubbo-samples-resilience4j/dubbo-samples-resilience4j-filter/pom.xml b/java/dubbo-samples-resilience4j/dubbo-samples-resilience4j-filter/pom.xml
index a59392e..e36188b 100644
--- a/java/dubbo-samples-resilience4j/dubbo-samples-resilience4j-filter/pom.xml
+++ b/java/dubbo-samples-resilience4j/dubbo-samples-resilience4j-filter/pom.xml
@@ -35,6 +35,7 @@
         <dubbo.version>2.7.5</dubbo.version>
         <dubbo.rpc.version>2.7.5</dubbo.rpc.version>
         <zookeeper.version>3.4.13</zookeeper.version>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
         <curator.version>4.0.1</curator.version>
         <validation-api.version>1.1.0.Final</validation-api.version>
         <hibernate-validator.version>4.2.0.Final</hibernate-validator.version>
@@ -191,6 +192,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>io.netty</groupId>
diff --git a/java/dubbo-samples-resilience4j/dubbo-samples-resilience4j-springboot2/pom.xml b/java/dubbo-samples-resilience4j/dubbo-samples-resilience4j-springboot2/pom.xml
index 556f6b0..a205330 100644
--- a/java/dubbo-samples-resilience4j/dubbo-samples-resilience4j-springboot2/pom.xml
+++ b/java/dubbo-samples-resilience4j/dubbo-samples-resilience4j-springboot2/pom.xml
@@ -36,6 +36,7 @@
         <dubbo.version>2.7.5</dubbo.version>
         <dubbo.rpc.version>2.7.5</dubbo.rpc.version>
         <zookeeper.version>3.4.13</zookeeper.version>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
         <curator.version>4.0.1</curator.version>
         <validation-api.version>1.1.0.Final</validation-api.version>
         <hibernate-validator.version>4.2.0.Final</hibernate-validator.version>
@@ -192,6 +193,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>io.netty</groupId>
diff --git a/java/dubbo-samples-rest/pom.xml b/java/dubbo-samples-rest/pom.xml
index bf9a0bd..52c7aa3 100644
--- a/java/dubbo-samples-rest/pom.xml
+++ b/java/dubbo-samples-rest/pom.xml
@@ -33,6 +33,7 @@
         <dubbo.version>2.7.5</dubbo.version>
         <dubbo.rpc.version>2.7.5</dubbo.rpc.version>
         <zookeeper.version>3.4.13</zookeeper.version>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
         <curator.version>4.0.1</curator.version>
         <validation-api.version>1.1.0.Final</validation-api.version>
         <hibernate-validator.version>4.2.0.Final</hibernate-validator.version>
@@ -188,6 +189,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>io.netty</groupId>
@@ -229,6 +231,7 @@
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-web</artifactId>
+            <version>${spring.version}</version>
         </dependency>
         <dependency>
             <groupId>javax.servlet</groupId>
diff --git a/java/dubbo-samples-scala/pom.xml b/java/dubbo-samples-scala/pom.xml
index 21c1738..2bf6599 100644
--- a/java/dubbo-samples-scala/pom.xml
+++ b/java/dubbo-samples-scala/pom.xml
@@ -33,6 +33,7 @@
         <dubbo.version>2.7.5</dubbo.version>
         <dubbo.rpc.version>2.7.5</dubbo.rpc.version>
         <zookeeper.version>3.4.13</zookeeper.version>
+        <dubbo.configcenter.zookeeper.version>2.7.4</dubbo.configcenter.zookeeper.version>
         <curator.version>4.0.1</curator.version>
         <validation-api.version>1.1.0.Final</validation-api.version>
         <hibernate-validator.version>4.2.0.Final</hibernate-validator.version>
@@ -189,6 +190,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo-configcenter-zookeeper</artifactId>
+            <version>${dubbo.configcenter.zookeeper.version}</version>
         </dependency>
         <dependency>
             <groupId>io.netty</groupId>
diff --git a/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-annotation/pom.xml b/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-annotation/pom.xml
index b2f4eb1..9f97c4a 100644
--- a/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-annotation/pom.xml
+++ b/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-annotation/pom.xml
@@ -32,7 +32,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7-SNAPSHOT</dubbo.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>
         <docker-maven-plugin.version>0.30.0</docker-maven-plugin.version>
diff --git a/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-nosimple/pom.xml b/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-nosimple/pom.xml
index cc37af0..e74823d 100644
--- a/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-nosimple/pom.xml
+++ b/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-nosimple/pom.xml
@@ -32,7 +32,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7-SNAPSHOT</dubbo.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>
         <docker-maven-plugin.version>0.30.0</docker-maven-plugin.version>
diff --git a/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-properties/pom.xml b/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-properties/pom.xml
index 7ce6b71..1ce9546 100644
--- a/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-properties/pom.xml
+++ b/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-properties/pom.xml
@@ -32,7 +32,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.6</dubbo.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>
         <docker-maven-plugin.version>0.30.0</docker-maven-plugin.version>
diff --git a/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-xml/pom.xml b/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-xml/pom.xml
index 8af1872..2fd7492 100644
--- a/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-xml/pom.xml
+++ b/java/dubbo-samples-simplified-registry/dubbo-samples-simplified-registry-xml/pom.xml
@@ -32,7 +32,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.6</dubbo.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>
         <docker-maven-plugin.version>0.30.0</docker-maven-plugin.version>
diff --git a/java/dubbo-samples-stub/pom.xml b/java/dubbo-samples-stub/pom.xml
index 5d1de8a..5fb9ec5 100644
--- a/java/dubbo-samples-stub/pom.xml
+++ b/java/dubbo-samples-stub/pom.xml
@@ -31,7 +31,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.6</dubbo.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>
         <docker-maven-plugin.version>0.30.0</docker-maven-plugin.version>
diff --git a/java/dubbo-samples-validation/pom.xml b/java/dubbo-samples-validation/pom.xml
index 2116222..6d4a61a 100644
--- a/java/dubbo-samples-validation/pom.xml
+++ b/java/dubbo-samples-validation/pom.xml
@@ -29,9 +29,12 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7-SNAPSHOT</dubbo.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>
+        <validation.api.version>2.0.1.Final</validation.api.version>
+        <hibernate.validator.version>6.1.2.Final</hibernate.validator.version>
+        <javax.el.version>3.0.0</javax.el.version>
         <docker-maven-plugin.version>0.30.0</docker-maven-plugin.version>
         <jib-maven-plugin.version>1.2.0</jib-maven-plugin.version>
         <maven-compiler-plugin.version>3.7.0</maven-compiler-plugin.version>
@@ -72,16 +75,19 @@
         <dependency>
             <groupId>javax.validation</groupId>
             <artifactId>validation-api</artifactId>
+            <version>${validation.api.version}</version>
         </dependency>
 
         <dependency>
             <groupId>org.hibernate</groupId>
             <artifactId>hibernate-validator</artifactId>
+            <version>${hibernate.validator.version}</version>
         </dependency>
 
         <dependency>
             <groupId>org.glassfish</groupId>
             <artifactId>javax.el</artifactId>
+            <version>${javax.el.version}</version>
         </dependency>
 
         <dependency>
diff --git a/java/dubbo-samples-zipkin/pom.xml b/java/dubbo-samples-zipkin/pom.xml
index 2ae41ec..f0b2f73 100644
--- a/java/dubbo-samples-zipkin/pom.xml
+++ b/java/dubbo-samples-zipkin/pom.xml
@@ -28,7 +28,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>2.7.6-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7-SNAPSHOT</dubbo.version>
         <curator.version>2.12.0</curator.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <junit.version>4.12</junit.version>