[java] How do I change the IntelliJ IDEA default JDK?

I use IntelliJ IDEA as my development environment, and Maven for dependency management. I frequently build my project structure (directories, poms, etc) outside of IDEA and then import the project into IDEA using Import project from external model. This works great, except that in my poms I specify that the maven-compiler-plugin should use JDK 1.6, and when I import, IDEA informs me that the Language Level Changed and that Language level changes will take effect on project reload, and then prompts to reload the project. This is annoying because I always use the same JDK version.

How do I change the default JDK that IntelliJ IDEA uses, so that I don't have to reload my project every time I import a new project?

I have found out that in recent versions of IntelliJ IDEA requires Java 1.8 but is not configured by default.

We can change the path or configure from Project Settings > Project > Project SDK

here we can edit or add the JDK´s path.

(in my case the path is located in C:\Program Files\Java\jdk1.8.0_102)

For latest version intellij, to set default jdk/sdk for new projects go to

Configure->Structure for New Projects -> Project Settings -> Project SDK

I am using IntelliJ 2020.3.1 and the File > Other Settings... menu option has disappeared. I went to Settings in the usual way and searched for "jdk". Under Build, Execution, Deployment > Build Tools > Maven > Importing I found the the setting that will solve my specific issue:

JDK for importer.

On my linux machine I use a script like this:

export IDEA_JDK=/opt/jdk14
/idea-IC/bin/idea.sh

The above responses were very useful, but after all settings, the project was running with the wrong version. Finally, I noticed that it can be also configured in the Dependencies window. Idea 2018.1.3 File -> Project Structure -> Modules -> Sources and Dependencies.

To change the JDK version of the Intellij-IDE himself:

Start the IDE -> Help -> Find Action

than type:

Switch Boot JDK

or (depend on your version)

Switch IDE boot JDK

Download and unpack a JDK archive file (.tar.gz) and add it as a SDK in the 'Project Structure' dialog box ( Ctrl+Alt+Shift+S )

click on the gif to enlarge

Make sure to set the 'Project language level' as well.

Change JDK version to 1.8

1. Language level File -> project Structure -> Modules -> Sources -> Language level -> 8-Lambdas, type annotations etc.

2. Project SDk File -> project Structure -> Project 1.8

3. Java compiler File -> Settings -> Build, Executions, Deployment -> Compiler -> Java compiler

• I am using IntelliJ IDEA 14.0.3, and I also have same question. Choose menu File \ Other Settings \ Default Project Structure...

• Choose Project tab, section Project language level, choose level from dropdown list, this setting is default for all new project.
  
  

One other place worth checking: Look in the pom.xml for your project, if you are using Maven compiler plugin, at the source/target config and make sure it is the desired version of Java. I found that I had 1.7 in the following; I changed it to 1.8 and then everything compiled correctly in IntelliJ.

<build>
<plugins>
    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>2.3.2</version>
        <configuration>
            <source>1.8</source>
            <target>1.8</target>
            <encoding>UTF-8</encoding>
        </configuration>
    </plugin>
</plugins>
</build>