添加编译级别插件

skywalking-sdk-plugin/dubbo-plugin/pom.xml

@@ -126,6 +126,14 @@
     </dependencies>
     <build>
         <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.6</source>
+                    <target>1.6</target>
+                    <encoding>${project.build.sourceEncoding}</encoding>
+                </configuration>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-deploy-plugin</artifactId>

skywalking-sdk-plugin/httpclient-4.2.x-plugin/pom.xml

@@ -32,6 +32,14 @@
     </dependencies>
     <build>
         <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.6</source>
+                    <target>1.6</target>
+                    <encoding>${project.build.sourceEncoding}</encoding>
+                </configuration>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-deploy-plugin</artifactId>

skywalking-sdk-plugin/httpclient-4.3.x-plugin/pom.xml

@@ -35,4 +35,16 @@
             <version>4.3</version>
         </dependency>
     </dependencies>
+    <build>
+        <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.6</source>
+                    <target>1.6</target>
+                    <encoding>${project.build.sourceEncoding}</encoding>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
 </project>

skywalking-sdk-plugin/jdbc-plugin/pom.xml

@@ -39,6 +39,14 @@
 
     <build>
         <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.6</source>
+                    <target>1.6</target>
+                    <encoding>${project.build.sourceEncoding}</encoding>
+                </configuration>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-deploy-plugin</artifactId>

skywalking-sdk-plugin/web-plugin/pom.xml

@@ -39,6 +39,14 @@
 
 	<build>
 		<plugins>
+			<plugin>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<configuration>
+					<source>1.6</source>
+					<target>1.6</target>
+					<encoding>${project.build.sourceEncoding}</encoding>
+				</configuration>
+			</plugin>
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-deploy-plugin</artifactId>