Usage of API documented as @since 1.8+

this may useful when development is performed under newer sdk version as the target platform for production

The configuration in pom.xml is.

        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
        </plugin>

Method 1: open project structure, select modules in the sidebar, and modify the language level in the sources window

Method 2: modify POM. XML to

        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
          <configuration>
            <source>11</source>
            <target>11</target>
          </configuration>
        </plugin>