IntelliJ Idea Maven plugin attempts to compile in Java 1.7 when configured for 1.8 (Mac)

Question

I'm attempting to run a maven target against an example project while ramping up on a new project. I'm new to both Mac and IntelliJ (I'm running community edition side-by-side with Eclipse Luna while I evaluate it). This all works in Eclipse and from the terminal.

The problem I'm having is getting Maven to run it in Java 8. I've configured JAVA_HOME to 1.8, set the project JDK to 1.8, language level to 1.8, etc. The code compiles (with lambdas) so 1.8 is clearly what IntelliJ is using. But the Maven plugin doesn't seem to want to honor that setting.

Here's the maven target configuration (using the Deploy target): Working Directory: /Users/brian.trezise/IdeaProjects/exampleservice Command Line: clean install tomcat7:run

When I execute the target from the Maven Projects popout, this is what it executes:

/Library/Java/JavaVirtualMachines/jdk1.8.0_11.jdk/Contents/Home/bin/java -Dmaven.home=/usr/local/Cellar/maven/3.2.2/libexec -Dclassworlds.conf=/usr/local/Cellar/maven/3.2.2/libexec/bin/m2.conf -Didea.launcher.port=7532 "-Didea.launcher.bin.path=/Applications/IntelliJ IDEA 13 CE.app/bin" -Dfile.encoding=UTF-8 -classpath "/usr/local/Cellar/maven/3.2.2/libexec/boot/plexus-classworlds-2.5.1.jar:/Applications/IntelliJ IDEA 13 CE.app/lib/idea_rt.jar" com.intellij.rt.execution.application.AppMain org.codehaus.classworlds.Launcher -Didea.version=13.1.4 clean install tomcat7:run

It seems to run fine up until Maven tries to compile (downloads all the dependencies, etc) then I get the following error:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project inin-example-app: Compilation failure
[ERROR] /Users/brian.trezise/IdeaProjects/exampleservice/src/main/java/com/inin/example/controller/PingController.java:[53,49] lambda expressions are not supported in -source 1.7
[ERROR] (use -source 8 or higher to enable lambda expressions)

I'm not sure how to configure it to use "-source 8" (if I add that to the command line it just fails).

Anybody willing to take pity on a IntelliJ newb?

score 4 · Accepted Answer · answered Aug 01 '14 at 16:10

It looks like you may be missing the compiler plugin from your Maven build, and so it is defaulting to 1.7, try adding the following to your pom.xml build section

        <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>
            </configuration>
        </plugin>

score 0 · Answer 2 · edited May 23 '17 at 12:32

I tried making changes to Intellij IDEA as below:

1.

File >> Settings >> Build, Execution, Deployment >> Compiler >> Java Compiler >> project bytecode version: 1.8 >> Per-module bytecode version: 1.8

2.

File >> Project Structure >> Project Settings >> Project >> SDK : 1.8, Project Language : 8 - Lambdas
File >> Project Structure >> Project Settings >> Modules >> abc : Language level: 8 - Lambdas

but nothing worked, it reverted the versions to java 1.5 as soon as I saved it.

However, 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: IntelliJ IDEA 13 uses Java 1.5 despite setting to 1.7

IntelliJ Idea Maven plugin attempts to compile in Java 1.7 when configured for 1.8 (Mac)

2 Answers2