How do I change the IntelliJ IDEA default JDK?

This setting is changed in the "Structure for New Projects" dialog. Navigate to "File" -> "New Projects Setup" -> "Structure..."

https://i.stack.imgur.com/D8swA.png

Next, modify the "Project SDK" and "Project Language Level" as appropriate.

https://i.stack.imgur.com/VTbzR.png

Previous versions of IntelliJ IDEA had this setting in "File" -> "Other Settings" -> "Default Project Structure...".

IntelliJ IDEA 12 had this setting in "Template Project Structure..." instead of "Default Project Structure..."

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 )

https://i.stack.imgur.com/if4hS.gif

Make sure to set an appropriate 'Project language level' as well.

For Java 8 set it to 8, for Java 9 set it to 9, and so on.

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

https://i.stack.imgur.com/maHVi.png

Choose Project tab, section Project language level, choose level from dropdown list, this setting is default for all 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)

https://i.stack.imgur.com/QwSu3.png

https://i.stack.imgur.com/8XfEw.png

Change JDK version to 1.8

Language level File -> project Structure -> Modules -> Sources -> Language level -> 8-Lambdas, type annotations etc. Project SDk File -> project Structure -> Project 1.8 Java compiler File -> Settings -> Build, Executions, Deployment -> Compiler -> Java compiler

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>

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

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.

https://i.stack.imgur.com/4b4pA.png

On my linux machine I use a script like this:

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