找到Maven安装路径下的settings.xml文件，我这里是 D:\Java\apache-maven-3.5.4\conf\settings.xml
在<profiles>标签下新增profile，默认是被注释掉的
<profiles> <profile> <id>jdk-1.8</id> <activation> <activeByDefault>true</activeByDefault> <jdk>1.8</jdk> </activation> <properties> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> <maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion> </properties> </profile> </profiles>