Resolving Maven Compilation Error: Invalid Flag –release in IntelliJ IDEA

Encountering the Maven compilation error Fatal error compiling: invalid flag: --release is a common issue. This arises when the Maven Compiler Plugin encounters an unrecognized flag, specifically the --release flag related to specifying the version of the Java runtime to use.

Possible Solutions:

Option 1: Downgrade Spring Version

If you prefer to stick with your current Java SDK version, you can downgrade the Spring framework version to one that supports Java 1.8.

1. Open your pom.xml file.
2. Locate the Spring dependencies and change the version to a compatible one. For example:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter</artifactId>
    <version>2.5.4</version> <!-- Change this to a version compatible with Java 1.8 -->
</dependency>

3. Save the file and run mvn clean install to rebuild your project.

Option 2: Upgrade Java SDK Version

If you prefer to stick with your current Spring version, consider upgrading your Java SDK to one supported by that version of Spring.

1. Download and install a compatible version of the Java Development Kit (JDK). Ensure that it is at least JDK 9 or higher.
2. Update your system’s JAVA_HOME environment variable to point to the newly installed JDK.
3. Open your pom.xml file and ensure that the maven.compiler.source and maven.compiler.target properties are set to the desired Java version:

<properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
</properties>

4. Save the file and run mvn clean install to rebuild your project.

By either downgrading the Spring version to support Java 1.8 or upgrading your Java SDK to be compatible with your current Spring version, you can resolve the invalid flag: --release error. Choose the solution that best aligns with your project requirements and preferences. Always ensure your development environment is appropriately configured to avoid compatibility issues.

Happy coding!