How to change Java version for Maven in IntelliJ?

I'm new to both Maven and IntelliJ IDEA.

I have a Maven project written in Java 8. Whenever I try to build it (Maven Projects window -> Lifecycle -> compile -> Run Maven Build) I get a series of compilation errors:

[ERROR] path/to/file.java:[26,52] lambda expressions are not supported in -source 1.5
(use -source 8 or higher to enable lambda expressions)

Where am I supposed to change the value of the -source parameter? I tried adding it as an additional parameter in Settings -> Compiler - > Java Compiler, but I got the same results.

The project's and module's language levels are both set to 8.0.

I'm using Maven 3.2.3 and IntelliJ IDEA Community Edition 13.1.2.

Or easier, add this to your pom's properties section:

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

Summary:

• 'maven-compiler-plugin' ALWAYS work! It is what I suggest you to use.

To change the language level, make usage of

<build>
    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>1.4</source>
                <target>1.4</target>
            </configuration>
        </plugin>
    </plugins>
</build>

The properties do not always change the language level of Intellij!

In the code below, 1.4 was configured in the pom using maven-compiler-plugin
(the jdk of Intellij is 1.8) and the language level of the project was changed accordingly to 1.4:

It was double-checked! It is an example. Most of the time you will not downgrade the version of the JDK to 1.4!

Of course if you use properties, let's say you put in the pom 1.8, then if you use a 1.8 JDK in Intellij(the language level default is 1.8 or the language default was changed manually), then you will be able to code in 1.8 BUT at the mvn compile, the properties will NOT be seen and you will default to Maven 1.5 and the compilation will NOT succeed !

I don't think any response to the question addressed the concern - ". . . in IntelliJ".

Here are the steps: -

• Go to Preferences in IntelliJ ( or Shortcut ⌘ + ,)
• Build, Execution, Deployment > Maven > Importer - select the "JDK for Importer" dropdown then select your preferred java version, Click Apply
• Build, Execution, Deployment > Maven > Runner - select the "JRE" dropdown then select your preferred java version, Click Apply
• Click OK

Change the source as shown below in pom.xml

<build>
		<finalName>MQService</finalName>
		<plugins>
			<plugin>
				<artifactId>maven-compiler-plugin</artifactId>
				<configuration>
					<source>1.8</source>
					<target>1.8</target>
				</configuration>
			</plugin>
		</plugins>
	</build>

Adding below lines to root(project level) pom.xml worked me to resolve above issue: (both of the options worked for me)

Option 1:

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

Option 2:

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

originally posted at: https://stackoverflow.com/questions/21006136/intellij-idea-13-uses-java-1-5-despite-setting-to-1-7/43268486#43268486

It may sometimes happen that after configuring maven in Intellij and changing as following it does not work by command build, so build it by Intellij maven tool.

Setting > Maven > Importer - select the `JDK` 
Setting > Maven > Runner - select the `JRE`

After that, try to build by Intellij maven tool instead of Intellij console.

There are two ways of doing this :

First- Add Properties

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

second- Add Plugin

<plugin>
    	<artifactId>maven-compiler-plugin</artifactId>
    	<version>3.5.1</version>
    	<configuration>
    		<source>1.8</source>
    		<target>1.8</target>
    	</configuration>
</plugin>

Here are the steps for intellij version# 2021.2 Ultimate Edition: -

Go to Settings in IntelliJ
Build, Execution, Deployment > Build Tools > Maven > importing > "JDK for Importer" then select your preferred java version, Click Apply
Build, Execution, Deployment > Build Tools > Maven > Runner > For "JRE" option select your preferred java version, 
Click Apply
Click OK

You should add below code in your pom.xml to force the language level to change

<build>
	<plugins>
		<plugin>
			<groupId>org.apache.maven.plugins</groupId>
			<artifactId>maven-compiler-plugin</artifactId>
			<configuration>
				<source>8</source>
				<target>8</target>
			</configuration>
		</plugin>
	</plugins>
</build>

now intelliJ 2019.3 CE does this for you if you go to import then alt+enter where you will get an option saying "change language level to 8 to use this functionality"

open the ubuntu terminal goto your root directory and type:

export JAVA_HOME = <path to jdk>

for example, it works fine for me {do the same in IntelliJ terminal}.

export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64

to check the set value type echo $JAVA_HOME

to check the maven version type: mvn -version

you can find all path of JDKs by typing this command, and you can set JDK version.

sudo update-alternatives --config java

also check you have same java -version and javac -version.