IntelliJ: Error:java: error: release version 5 not supported

Question

See https://stackoverflow.com/a/12900859/104891.

First of all, set the language level/release versions in pom.xml like that:

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

Maven sets the default to 1.5 otherwise. You will also need to include the maven-compiler-plugin if you haven't already:

<dependency>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-compiler-plugin</artifactId>
  <version>3.8.1</version>
</dependency>

Also, try to change the Java version in each of these places:

File -> Project structure -> Project -> Project SDK -> 11.

File -> Project structure -> Project -> Project language level -> 11.

File -> Project structure -> Project -> Modules -> -> Sources --> 11

In project -> ctrl + alt + s -> Build, Execution, Deployment -> Compiler -> Java Compiler -> Project bytecode version -> 11

In project -> ctrl + alt + s -> Build, Execution, Deployment -> Compiler -> Java Compiler -> Module -> 1.11.

Took me a while to aggregate an actual solution, but here's how to get rid of this compile error.

1. Open IntelliJ preferences.

2. Search for "compiler" (or something like "compi").

3. Scroll down to Maven -->java compiler. In the right panel will be a list of modules and their associated java compile version "target bytecode version."

4. Select a version >1.5. You may need to upgrade your jdk if one is not available.

By default, your "Project bytecode version isn't set in maven project.

It thinks that your current version is 5.

Solution 1:

Just go to "Project Settings>Build, Execution...>compiler>java compiler" and then change your bytecode version to your current java version.

Solution 2:

Adding below build plugin in POM file:

 <properties>
        <java.version>1.8</java.version>
        <maven.compiler.version>3.8.1</maven.compiler.version>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>${maven.compiler.version}</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

I add the following code to my pom.xml file. It solved my problem.

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
</properties>