IntelliJ IDEA source value 1.5 is outdated and will be deleted in all future versions.

IntelliJ IDEA source value 1.5 is outdated and will be deleted in all future versions.

1. Modify the Settings. xml file of Maven and add the following content:

<Profile> <id> jdk-1.8 </id> <activation> <activeByDefault> true </activeByDefault> <jdk> 1.8 </jdk> </activation> <properties> <maven. compiler. source & gt; 1.8 </maven. compiler. source> <maven.compiler.tar get> 1.8 </maven.compiler.tar get> <maven. compiler. compilerVersion & gt; 1.8 </maven. compiler. compilerVersion> </properties> </profile>

2. Add the following in the pom. xml file of the project:

<Properties> <maven. compiler. source> 1.8 </maven. compiler. source> <maven.compiler.tar get> 1.8 </maven.compiler.tar get> </properties>

3. Open the project configuration and Set Modules's Language Level to "8"

Finally, press Ctrl + Alt + S to open the settings, search for "Java Compiler", and switch the jdk version of the default jdk and the current modual jdk version to 1.8.