How to find and change Java compiler option in Visual Studio Code?

VS Code does not have built-in support for Java projects. You need to install some Java extensions and configure them to specify the correct Java JDK version, which you can do by either setting the JAVA_HOME environment variable or by setting the java.home setting:

After installing the JDK, you would need to configure your environment for Java development. The most common way is to set JAVA_HOME environment variable to the install location of the JDK while you can also use java.home setting in Visual Studio Code settings (workspace or user settings) to configure it just for the editor.

I described the installation/setup steps below. It is mainly based on the Visual Studio Code tutorial for Java. Based on the OP's comment, it's focused on the Java extension for VSCode on Mac.

MacOS

First, you need to install the Microsoft Java Extension Pack.

Upon installation, it will display the Java Overview tab, and automatically check for available Java SDKs. If it cannot find one, it will prompt you to download one. (The Java Overview and this JDK Required page seems to also auto-appear when you open/create a .java file).

From the VS Code documentation, these JDK distributions should be supported: OpenJDK, Java SE from Oracle, Azul Zulu Enterprise. For this answer, I am using OpenJDK 11. Download and install the appropriate JDK.

Next, get the path to your JDK. Open a Terminal and then:

$ /usr/libexec/java_home
/Library/Java/JavaVirtualMachines/adoptopenjdk-11.jdk/Contents/Home

If you already have a JAVA_HOME env var set, I recommend not relying on it. I find that it is better to use the java.home setting to configure Java specifically for VS Code (or for a particular workspace).

Now, open the VS Code Settings tab and look for the Java: Home setting:

You can modify either the User or Workspace setting. In the screenshot above, I am modifying my User settings, making the java.home setting affect all Java projects. You can also modify the Workspace setting to configure java.home differently for each workspace.

Click on the Edit in settings.json, and add java.home (you'll know your extension was installed properly if java.* autocompletion is displayed).

Specify the path to the JDK you got earlier:

"java.home": "/Library/Java/JavaVirtualMachines/adoptopenjdk-11.jdk/Contents/Home",

Then restart VS Code. When the Java Overview tab displays again, if you set the path correctly, it should not prompt you anymore to download a JDK, meaning it found your JDK. Try running a very basic HelloWorld.java application.

Windows

If you are on Windows, they provide a special installer to help you get started:

To help you get started quickly, we created a special Installer of Visual Studio Code for Java developers.

Download Visual Studio Code Java Pack Installer

Note: The installer is currently only available for Windows. For other OS, please install those components (JDK, VS Code and Java extensions) individually. We're working on the macOS version, please stay tuned.

In visual studio code, you need to change your compliance version in below file

• Filename: org.eclipse.jdt.core.prefs
• path: Your_project_directory/.settings/org.eclipse.jdt.core.prefs

(.settings will be hidden in file explorer will be visible only in vs code.)

Also, change from 1.7 to 1.8 in the file. 1.8 is the java version based upon the java version input the value

Using all your answers, I realized that the error was on a project made of Javascript Angular, no need of Java. Then I deleted the directory ".settings" and file ".classpath".. and these 2 errors disappear.

Thank to all.

Add to .vscode/settings.json:

{
    "java.jdt.ls.java.home": "<location-of-your-preferred-jdk>"
}

Note: This is only for the current project.

Edit: My pom.xml file was not correct. If you use Maven, take a other look on that file.

For me, it was in the ".settings" folder (it should be in your Java project). There's some "org.eclipse" files in there. You just need to change the 1.5 to 1.8.

In my case, I had a jdk8 in environment and I need to compile the java file to class file in Jre 1.7 version. The class files major.minus version need 0x33.

So I need to use the vscode-java to create the class files. But the vscode do not has the setting for compiler. The eclipse project has a setting file in .setting/org.eclipse.jdt.core.prefs. Settings Global Preferences

eclipse.preferences.version=1
org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.7
org.eclipse.jdt.core.compiler.compliance=1.7
org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
org.eclipse.jdt.core.compiler.source=1.7

This file can change the compiler option in eclipse jdt.

The vscode-java extension has a setting option to use specific setting file. We can add the code below to the .vscode/setting.json to change the java compiler target version.

"java.settings.url": ".settings/org.eclipse.jdt.core.prefs",

As a result the class file compiled has a 0x33 jre major.minor version.

Looks like there are a lot of answers here. IMO it's a little confusing because it seems like there are multiple Java Plugins, and multiple ways to set the JDK / JVM for each plugin.

I seem to be using the Redhat plugin. If using the Redhat plugin and a JDK < 17 then I found the way to set JVMs here: https://github.com/redhat-developer/vscode-java/wiki/JDK-Requirements#java.configuration.runtimes