IntelliJ IDEA - java 8 error FIX - Usage of API documented as @since 1.7+ less... (Ctrl+F1)

Usage of API documented as @since 1.7+ less... (Ctrl+F1)

Inspection info: This inspection finds all usages of methods that have 

@since tag in their documentation.

This may be useful when development is performed under newer SDK version 

as the target platform for production.

1. Open Project Structure -> Project

-> Project SDK -> change to java / jdk 8

​

2. Open Project Structure -> Project

-> Project language level -> change to: "8 - Lambdas, type annotations etc."

​

3. Open Project Structure -> Modules

-> Language level - change to: "Lambdas, type annotations etc."

​

4. Open Settings -> Build, Execution, Deployment -> Compiler

-> Java Compiler -> Target bytecode version -> change to: "8"

<build>

   <plugins>

      <plugin>

         <groupId>org.apache.maven.plugins</groupId>

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

         <version>3.8.0</version>

         <configuration>

            <source>1.8</source>

            <target>1.8</target>

         </configuration>

      </plugin>

   </plugins>

</build>