Default methods are allowed only at source level 1.8 or above,java代码出错

修改maven配置文件，添加如下代码：

<properties>

     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

     <java.version>1.8</java.version>

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

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

</properties>