Using IntelliJ IDE can't compile any projects. Screenshots of settings below:
Used JDK:
Project SDK and Language level:
Language Level:
Anybody have any ideas?
Using IntelliJ IDE can't compile any projects. Screenshots of settings below:
Used JDK:
Project SDK and Language level:
Language Level:
Anybody have any ideas?
If you are using Maven
Add the compiler plugin to pom.xml
under the top-level project
node:
<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>
(Hoisted from the comments.)
Note: If you don't mind reimporting your project, then the only thing you really need to do is change the pom and reimport the project, then IntelliJ will pick up the correct settings and you don't have to manually change them.
This looks like the kind of error that Maven generates when you don't have the compiler plugin configured correctly. Here's an example of a Java 8 compiler config.
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<!-- ... -->
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.5.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
<!-- ... -->
</project>
Many answers regarding Maven are right but you don't have to configure the plugin directly.
Like described on the wiki page of the Apache Maven Compiler Plugin you can just set the 2 properties used by the plugin.
<project>
[...]
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
[...]
</project>
In my case I fixed this issue by opening .iml file of project (it is located in project root folder and have name same as the name of project) and changing line <orderEntry type="jdk" jdkName="1.7" jdkType="JavaSDK" />
to <orderEntry type="jdk" jdkName="1.8" jdkType="JavaSDK" />
I had everything configured as in others answers here but by some reason Idea updated .iml file incorrectly.
I fixed it by modify my POM file. Notice the last comment under the highest voted answer.
<plugin>
<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>
The source must matches the target.
For me, the problem was about Maven not able to find proper configurations, since these items were specified in parent pom.
Changing File -> Settings -> Build, Excecution, Deployment -> Maven -> User Settings file to point to my custom settings with proper repositories fixed the problem that was otherwise hiding.
Found out about the problem through Help -> Show log in explorer -> clicking the log file, when previously only got the error in the title and "java.lang.NullPointerException" in the console.
With Intellij, using Maven, you must check that Intellij has auto-imported your project. You can check by clicking on the Maven tab on the right of your Editor.
If your Project is not here, then add the pom.xml
file by clicking on +
.
Obviously, the project must also have the relevant <build/>
:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
If none of the other answers work, check your Module SDK.
I had this error pop up for me after I had updated the project SDK to 1.8, the Javac compiler to 1.8, etc. The setting that was the problem for me was the "Module SDK".
(on Linux) Go to File > Project Structure...
then in the window that opens, select Modules
under Project Settings
. Select the module in question from the list and then the Dependencies
tab and make sure that Module SDK
is set appropriately.