IntelliJ 目标字节码恢复

Question

For a project that I'm currently working on, IntelliJ gave me the compile error Error:java: javacTask: source release 8 requires target release 1.8 . I went into Settings>Build, Execution, Deployment>Compiler>Java and saw that the target bytecode version for one of my modules was set to 1.5, so I changed it to 1.8, compiled, and it worked. But then the next day, I got the same error. I went into settings and the target bytecode for that one module was back at 1.5. I changed it to 1.8 and it compiled/ran just fine. This has now happened multiple times and I am frustrated by the number of times I have to go into settings to manually change the target bytecode version.

Why does the target bytecode version keep reverting? I don't have 1.5 specified in the pom or anywhere else, so I am baffled as to why the bytecode version keeps getting set to 1.5.

Answer 1

You need to specify the source and target versions in your pom.xml file, but since the maven-compiler-plugin is added by default, an easier way to do that would be to set the following properties:

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

Answer 2

You need to dd this to your POM:

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.3</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>

Answer 3

FYI.

I still had this problem despite setting the pom.xml with both the settings above from the answers as mentioned by @isapir and @carlos-a-ibarra respectively.

I discovered this was due to an Intellij setting:

This config can be found in Build,Execution,Deployment > Build Tools > Maven > Importing

By default, it is set to the 'Internal JRE' setting, which in the latest version of Idea is 11. I had to select it to use the 1.8 JDK the project was configured to use.

This is annoying, because if you have a mix of 11 and 8 projects, you'll have to manually toggle this setting back and forth.

It caused the module output to always fall back to 11 every time the pom.xml was reimported.

It's a really annoying bug in IntelliJ.

Answer 4

Please try below option, it worked for me.

step 01: Change the version under Module and project. step 02: build the module.

Hope it should resolve the issue.