Hey,

You should configure the compatibility outside of the tasks, i.e. as top-level elements of the build.gradle:

apply plugin: 'java'

sourceCompatibility = '1.7'
targetCompatibility = '1.7'

Denis,

If the users prefers different language level than the one assigned by Gradle he can configure it: http://gradle.org/docs/current/dsl/org.gradle.plugins.ide.idea.model.IdeaProject.html#org.gradle.plugins.ide.idea.model.IdeaProject

After configuring it, the tooling api will use that setting.

I'll close this issue if that's ok. Please reopen if necessary!

Yet another incarnation of somewhat poor support for language level in the Gradle's idea plugin.

Blocking this JetGradle feature: http://youtrack.jetbrains.com/issue/IDEA-83528

There is still no way to set language level per module (as opposed to globally for the project).

A use case would be, where we have a project that has multiple modules, some of them API libraries, shared with other applications. We need the whole project to use 1.8, except for the API we need to keep to 1.6.

Our Gradle build does proper cross-compilation, and we can hack the IDEA projects generated from Gradle, but the IDEA tooling can not access the per module language level as it is not exposed by the tooling api.

I have a multi module projects. I've placed the attributes as specified in the top level build.gradle file, and still IDEA looks at my module as if it is Java 6 instead of java 8:

sourceCompatibility = 1.8
targetCompatibility = 1.8

Hi Guys,
I face similar issue to what Asaf describes. Every time I start IDEA modules have Java language level reverted back to 1.6. Then I manually set this value to 1.8 for each module separately. This is remembered until I restart IDEA. Then I need to do that manual work again. It's really annoying.

For time being, can you suggest some work-around for this issue?

Is this project dead? Almost 4 years later, no solution?

Can any one clarify the status of this issue? It had been targeted for gradel 2.11-rc1, then reopened, but gradle 2.11 final Release Notes (https://docs.gradle.org/current/release-notes#enhanced-support-for-developing-java-projects-in-intellij-idea-and-eclipse) mention it like implemented.
But it does not work for me with gradle 2.11 and idea 15

From reading the 2.11 release notes I think IDEA needs a change as well to support this.

This issue has not been fixed yet.
Gradle's plugin for IDEA does not respect build.gradle's sourceCompatibility/targetCompatibility property, instead, it use IDEA's setting: File -> Other Settings -> Default Project Structure -> Project Language Level -> 6 (By default).

I have a gradle Java project. The build.gradle file is here,

apply plugin: 'java'
...
sourceCompatibility = 1.8
targetCompatibility = 1.8
...

When i run gradle in command line, the sourceCompatibility/targetCompatibility property does works.
(Because If i change it to 1.6, build fails. My gradle version is 2.11)

Then, i use IntelliJ IDEA 15 to import this gradle project, it generates some configuration files in .idea dir.
The .idea/misc.iml contains a language level property which is always set to 1.6:

  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_6" default="false" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
    <output url="file://$PROJECT_DIR$/classes" />
  </component>

Once i change IDEA's Default Project Structure's Project Language Level to 8, (see above screenshot, change 6 to 8),
then the imported project will works as excepted: use Language Level 8.
The auto-generated .idea/misc.xml contains:

  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="false" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
    <output url="file://$PROJECT_DIR$/classes" />
  </component>

I am still facing the same issue with language level defaulting back to 6 while the gradle file had the setting [ Gradle 2.11 and IntelliJ 15CE]
Current settings:

javac.configure {
        sourceCompatibility '1.8'
        targetCompatibility '1.8'
        options.encoding = 'UTF-8'
      }

After reading through the 2.11 release docs,

If a Gradle build script uses the DSL to explicitly specify idea.project.languageLevel, the sourceCompatibility level is not taken into account. In this case only the generated IDEA project will contain a value for 'Language Level', and no module-specific overrides will be generated.

I tried setting the languageLevel as 1.8 but IntelliJ threw an error

idea {
    project{
    languageLevel = '1.8'
    }
      module {
      downloadSources = true
      scopes.PROVIDED.plus += [ configurations.provided ]
    }
  }

Error :

Cannot set property 'languageLevel' on null object

Any updates or code modification are welcomed.