How to change project language level for all project in Intellij

Question

I am using Intellij. It is good, but when I create a new project or import a project the default project language level set to 6 (@override in interfaces). But I want to set

Answer 1

File -> Other Settings -> Default Project Structure...

You can change it in there.

(Edit: It's now called "Structure for New Projects")

Answer 2

I was able to resolve this problem by going to:

File -> Project Structure... And selecting an option from the dropdown under "Project language level"

Hope this helps!

Answer 3

I had same problem. Changing IntelliJ IDEA setting files (misc.xml, compiler.xml) has not helped. Then I changed language level in two places:

1) File -> Project Structure -> Modules, "Sources" tab, Language level 8 (or higher).

2) Settings -> Build, Execution,Deployment -> Compiler -> Java Compiler -> Target bytecode version (version 1.8)

This worked fine.

Answer 4

Same problem but slightly different solution. IntelliJ (2018.1.15) gave me the option to Set Language Level to 6 which I accepted. This added the following to the project .iml file:

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>6</source>
                <target>6</target>
            </configuration>
        </plugin>
    </plugins>
</build>

I was then able to update source & target to 8.

Answer 5

If it is a maven project, make sure that the following is set.

For example, if you want to use the Java 8 language features (-source 1.8) and also want the compiled classes to be compatible with JVM 1.8 (-target 1.8), you can either add the two following properties, which are the default property names for the plugin parameters:

<project>
  [...]
  <properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>
  [...]
</project>

For more details check this

Answer 6

I had to edit .idea/misc.xml and change languageLevel="JDK_1_7" to languageLevel="JDK_1_8". I've been unable to change the language level via the ui in osx.

** Intellij 15.0.4