You can not add annotations ------ IDEA Maven project at issue in changing the default JDK version 1.5 to 1.8

• This way from https://www.jb51.net/article/134995.htm , their use in this manner IDEA resolved, then slightly illustrates the use of this detail, i.e. brought to a

Need to check the position

• Maven configuration used is indeed their own default maven instead IDEA
  
• Java configuration used jdk has been configured properly, generally not a problem, but sometimes used 历史遗留when the project is low jdk version

1. Label a build a project configuration

This embodiment does not attempt, described by definition, global configuration, in Next, and Location tag to the same level of configuration

• Global Configuration (project build)
  • Valid for all of the entire project
• Configuration (profile build),
  • For different profile configuration
    

         <build> 
            <plugins> 
              <plugin> 
                <groupId>org.apache.maven.plugins</groupId> 
                <artifactId>maven-compiler-plugin</artifactId> 
                <version>3.1</version> 
                <configuration> 
                  <source>1.8</source> 
                  <target>1.8</target> 
                </configuration> 
              </plugin> 
            </plugins> 
          </build>   

2. maven configuration, all using the maven are to take effect

conf in the Maven installation directory under / settings.xml Add the following tag

        <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>