在 vscode 集成终端中使用替代 maven 和 java 版本

Question

I want to set the maven version and java version in vscode integrated terminal to versions other than those specified in system environment variables. I am using the "Maven for Java" extension in vscode.

I don't want to change my system environment variables / restart everytime I need to switch between my primary and secondary programming setting.

So far I have specified the "java.configuration.runtimes" and several other things in settings.json. The language server recognizes this setting - all fine. However, running java -version and mvn -version in the integrated terminal still shows the java version of my system environment and also has troubles with maven:

java -version
java version "1.8.0_172"
Java(TM) SE Runtime Environment (build 1.8.0_172-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.172-b11, mixed mode)
   
mvn -version
Unrecognized option: --add-opens
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

I got the mvn command to run once with some setting combination I can't remember. It was using the new java version but still the old mvn version interestingly.

Here is my settings.json

{
    "java.configuration.runtimes": [
        {
            "name": "JavaSE-11",
            "path": "C:\\Program Files\\Java\\jdk-11.0.7+10_hotspot",
            "default": true
        }
    ],
    "java.home": "C:\\Program Files\\Java\\jdk-11.0.7+10_hotspot",
    "terminal.integrated.shell.windows": "C:\\Program Files\\PowerShell\\7\\pwsh.exe",
    "terminal.integrated.fontFamily": "Cascadia Mono PL",
    "maven.executable.path": "C:\\maven-3.6.3\\bin\\mvn",
    "maven.terminal.useJavaHome": true,
    "maven.terminal.customEnv": [
        {
            "environmentVariable": "JAVA_HOME",
            "value": "C:\\Program Files\\Java\\jdk-11.0.7+10_hotspot"
        },
        {
            "environmentVariable": "M2_HOME",
            "value": "C:\\maven-3.6.3\\"
        },
        {
            "environmentVariable": "M2",
            "value": "C:\\maven-3.6.3\\bin"
        },
    ]
}

As the documentation of the Maven Extension says ( https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-maven ) "the value from maven.terminal.customEnv will take precedence [over the specification of java.home and useJavaHome]". Nevertheless, I tried choosing between one or the other but it doesn't make a difference.

Answer 1

When you run java --version in integrated Terminal in VS Code, it will search JAVA_HOME set in Environment Variables, so it's still jdk1.8 .

But when you run the file like helloworld.java , the execution scripts shown in Terminal should include C:\Program Files\Java\jdk-11.0.7+10_hotspot\bin\java.exe , which means java extension tools indeed uses jdk11 to build and compile projects.

About maven, you still need to add it to PATH, then mvn --version should work in Terminal:

If you set "maven.terminal.useJavaHome": true, , it will use JAVA_HOME in Environment Variables which is JDK1.8, you can specify jdk version with the following two ways:

1. When you create a maven project, you can choose jdk version manually;

2. In Maven projects' pom.xml , don't forget to rebuild the project:

    <properties> <java.version>11</java.version> </properties>

   More information view Apache Maven Compiler Plugin – Setting the -source and -target of the Java Compiler .