Force javac instead of eclipse jdt as compiler

[dawosch]

Hey, i'm using visual studio code with the "extension pack for java" extension.
Local i have installed java 17 (microsoft edition).
When i build my project with mvn -U clean install there will be classes generated and everything is fine.
But when i press shift + alt + B like your readme says, the code will be compiled with the eclipse jdt compiler, which seems to have problems with a dependecy called MapStruct.

Here is one file compiled with maven:

And here is the same file after pressing shift + alt + B:

Have a look at line 20.
When i start my project the java extension always recompile my code (with the eclipse compiler).
I disabled the auto build feature, but that changed nothing.
I also configured the runtimes for java 17 in hope that this version will be used for compiling my code, but it doesn't.

Here is a repository i created to reproduce the error: Repository

Here are also some settings of vscode:

{
  "java.configuration.updateBuildConfiguration": "automatic",
  "java.debug.settings.onBuildFailureProceed": true,
  "java.autobuild.enabled": false,
  "java.debug.settings.forceBuildBeforeLaunch": false,
  "java.jdt.ls.java.home": "C:\\Program Files\\Microsoft\\jdk-17.0.5.8-hotspot",
  "spring-boot.ls.java.home": "C:\\Program Files\\Microsoft\\jdk-17.0.5.8-hotspot",
  "java.compile.nullAnalysis.mode": "disabled",
  "java.configuration.runtimes": [
    {
      "name": "JavaSE-17",
      "path": "C:\\Program Files\\Microsoft\\jdk-17.0.5.8-hotspot",
      "default": true
    }
  ]
}

Environment

• Operating System: Windows 10
• JDK version: 17 (microsoft edition)
• Visual Studio Code version: 1.76.2 (user setup)
• Java extension version: 1.16.0

Steps To Reproduce

1. Clone my test repository
2. Run mvn -U clean install in the terminal
3. Have a look at the generated source file TestMapperInterfaceImpl.java on line 20 (the setter)
4. Press shift + alt + B to compile the project
5. Have a look at the same file and you will notice that the setter is gone

Test repository: Link to the repository

Current Result

The eclipse jdt compiler messed something up so the generated files are not working.

Expected Result

The compiler i defined in the runtime settings should be used to compile my code.

Additional Informations

I also opened a issue at the microsoft/vscode-spring-dashboard extension because i first thought that the error is a problem ob this extension because i started my project over this extension. But i noticed that before it starts it will be recompiled.
Link to the issue of the spring boot extension

[snjeza]

The issue is not related to eclipse jdt compiler.

@dawosch Could you try the following:

• move the mapstruct-accessing-strategy module to a separate project
• remove the mapstruct-accessing-strategy module from the com.example:parent project
• install mapstruct-accessing-strategy

$ mvn clean install

• open com.example:parent in VS Code or Eclipse
  TestMapperInterfaceImpl.java

package com.example.demo;

import javax.annotation.processing.Generated;

@Generated(
    value = "org.mapstruct.ap.MappingProcessor",
    date = "2023-03-20T01:40:43+0100",
    comments = "version: 1.5.3.Final, compiler: Eclipse JDT (IDE) 3.33.0.v20230218-1114, environment: Java 17.0.6 (Eclipse Adoptium)"
)
public class TestMapperInterfaceImpl implements TestMapperInterface {

    @Override
    public TestOutput toTestOutput(TestInput testInput) {
        if ( testInput == null ) {
            return null;
        }

        TestOutput testOutput = new TestOutput();

        testOutput.setValue( testInput.value() );

        return testOutput;
    }
}

See https://github.com/dawosch/vscode-java-extension-compiler-error/blob/main/app/pom.xml#L54

[dawosch]

Thanks for your answere.
Yes this seems to work fine.

But i'm wondering why the language server needs to recompile all files.
When i have java installed and all settings point to my java version, i would expect that the language server will use this java version to.

[snjeza]

The issue is related to the Java Service Provider. The provider configuration have to be packed into a jar file.
See https://docs.oracle.com/javase/tutorial/ext/basics/spi.html#package-in-jar-files

Note that the provider configuration file must be in the directory META-INF/services in the JAR file.

[rgrunber]

Closing this as it seems to have a solution. Also FWIW, we support javac-based compilation as well now : https://github.com/redhat-developer/vscode-java/wiki/Javac%E2%80%90based-compilation-support .