IDEA设置JAVA使用的编译语言Language level为8

设置这个为8 不然每次pom文件修改都会变更为5

pom.xml增加

 <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>8</java.version>
    </properties>

增加插件配置

<!-- 打包配置 -->
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.6.1</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                    <encoding>${project.build.sourceEncoding}</encoding>
                    <showWarnings>true</showWarnings>
                </configuration>
            </plugin>
        </plugins>
    </build>