mvn 报错 source-1.5 中不支持 diamond运算符

<properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
</properties>

参考：https://www.cnblogs.com/tongxuping/p/7257623.html

其他：

http://maven.apache.org/plugins/maven-compiler-plugin/examples/set-compiler-source-and-target.html

http://blog.csdn.net/kai161/article/details/50379418

http://blog.csdn.net/qh_java/article/details/52299062