Define source version
<artifactId>carbon-p2-plugin</artifactId>
<version>${carbon.p2.plugin.version}</version>
</plugin>
+ <plugin>
+ <groupId>org.apache.maven.plugins</groupId>
+ <artifactId>maven-compiler-plugin</artifactId>
+ <version>3.2</version>
+ <configuration>
+ <encoding>UTF-8</encoding>
+ <source>1.7</source>
+ <target>1.7</target>
+ </configuration>
+ </plugin>
</plugins>
<pluginManagement>
<plugins>
