Error:java: javacTask: source release 1.8 requires target release 1.8

1、File > Settings > Build, Execution, Deployment > Java Compiler
2、Change Target bytecode version to 1.8 of the module that you are working for.
If you are using Maven

Add this to pom.xml under the top-level project node:

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