Unexpected errors produced when "javac" support enabled with Lombok

[lyszhen3]

1. os:win11
2. jdk:openjdk24
3. project jdk:openjdk21
4. build with gradle

workspace setting

{ "java.import.gradle.home": "D:\\Applications\\Scoop\\apps\\gradle\\current\\", "java.import.gradle.java.home": "D:\\Applications\\Scoop\\apps\\openjdk21\\current", "java.configuration.updateBuildConfiguration": "interactive", "gradle.allowParallelRun": true, "java.compile.nullAnalysis.mode": "automatic", "java.jdt.ls.javac.enabled": "on", "java.completion.engine": "dom", "java.jdt.ls.vmargs": "-Xmx2G --enable-preview", "java.project.encoding": "setDefault", "java.jdt.ls.lombokSupport.enabled": false }
work good in self class

but not work in other class

build.gradle

plugins {
    `java-library`
    `maven-publish`
    id("io.freefair.lombok") version "8.14"
}


group = "com.j.c"
version = "0.0.1-SNAPSHOT"
description = "gradle-test"



allprojects{

    if (project.name == "gradle-platform") return@allprojects

    repositories {
        maven ( url="https://maven.aliyun.com/repository/public" )
        maven ( url="https://repo.maven.apache.org/maven2" )
        maven ( url="https://repo.spring.io/libs-snapshot" )
        maven ( url="https://repo.spring.io/libs-milestone" )
        mavenLocal()
        mavenCentral()
    }
    apply(plugin = "java-library")
    apply(plugin = "io.freefair.lombok")
    java.sourceCompatibility = JavaVersion.VERSION_21
    java.targetCompatibility = JavaVersion.VERSION_21


    tasks.withType<JavaCompile>() {
        options.encoding = "UTF-8"
        options.compilerArgs.add("--enable-preview")
    }

    tasks.withType<Javadoc>() {
        options.encoding = "UTF-8"
    }

}

publishing {
    publications.create<MavenPublication>("maven") {
        from(components["java"])
        }
}

errorlog

[Error - 4:57:53 PM] Jul 13, 2025, 4:57:53 PM Error in calling delegate command handler
gradle-platform does not exist
Java Model Exception: Error in Java Model (code 969): gradle-platform does not exist
at org.eclipse.jdt.internal.core.JavaElement.newNotPresentException(JavaElement.java:548)
at org.eclipse.jdt.internal.core.JavaModelManager.getPerProjectInfoCheckExistence(JavaModelManager.java:2549)
at org.eclipse.jdt.internal.core.JavaProject.getPerProjectInfo(JavaProject.java:2361)
at org.eclipse.jdt.internal.core.JavaProject.getResolvedClasspath(JavaProject.java:2434)
at org.eclipse.jdt.internal.core.JavaProject.getAllPackageFragmentRoots(JavaProject.java:1806)
at org.eclipse.jdt.internal.core.JavaProject.getAllPackageFragmentRoots(JavaProject.java:1797)
at com.microsoft.jdtls.ext.core.ProjectCommand.getMainClasses(ProjectCommand.java:243)
at com.microsoft.jdtls.ext.core.CommandHandler.executeCommand(CommandHandler.java:35)
at org.eclipse.jdt.ls.core.internal.handlers.WorkspaceExecuteCommandHandler$1.run(WorkspaceExecuteCommandHandler.java:230)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:47)
at org.eclipse.jdt.ls.core.internal.handlers.WorkspaceExecuteCommandHandler.executeCommand(WorkspaceExecuteCommandHandler.java:220)
at org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$4(JDTLanguageServer.java:616)
at org.eclipse.jdt.ls.core.internal.BaseJDTLanguageServer.lambda$0(BaseJDTLanguageServer.java:87)
at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:692)
at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:529)
at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:507)
at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1394)
at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1970)
at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:187)

Jul 13, 2025 4:57:53 PM org.eclipse.lsp4j.jsonrpc.RemoteEndpoint fallbackResponseError
����: Internal error: java.lang.NullPointerException: Cannot invoke "org.eclipse.jdt.core.IMethod.getCompilationUnit()" because "iMethod" is null
java.util.concurrent.CompletionException: java.lang.NullPointerException: Cannot invoke "org.eclipse.jdt.core.IMethod.getCompilationUnit()" because "iMethod" is null
at java.base/java.util.concurrent.CompletableFuture.wrapInCompletionException(CompletableFuture.java:325)
at java.base/java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:361)
at java.base/java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:366)
at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:695)
at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:529)
at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:507)
at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1394)
at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1970)
at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:187)
Caused by: java.lang.NullPointerException: Cannot invoke "org.eclipse.jdt.core.IMethod.getCompilationUnit()" because "iMethod" is null
at org.eclipse.jdt.internal.corext.refactoring.code.makestatic.InitialConditionsChecker.checkSourceAvailable(InitialConditionsChecker.java:181)
at org.eclipse.jdt.internal.corext.refactoring.code.MakeStaticRefactoring.checkInitialConditions(MakeStaticRefactoring.java:127)
at org.eclipse.jdt.ls.core.internal.corrections.RefactorProcessor.getMakeMethodStaticRefactoringProposal(RefactorProcessor.java:1189)
at org.eclipse.jdt.ls.core.internal.corrections.RefactorProcessor.getProposals(RefactorProcessor.java:228)
at org.eclipse.jdt.ls.core.internal.handlers.CodeActionHandler.getCodeActionCommands(CodeActionHandler.java:221)
at org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$15(JDTLanguageServer.java:775)
at org.eclipse.jdt.ls.core.internal.BaseJDTLanguageServer.lambda$0(BaseJDTLanguageServer.java:87)
at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:692)
... 5 more

[Error - 4:57:53 PM] Request textDocument/codeAction failed.
Message: Internal error.
Code: -32603
java.util.concurrent.CompletionException: java.lang.NullPointerException: Cannot invoke "org.eclipse.jdt.core.IMethod.getCompilationUnit()" because "iMethod" is null
at java.base/java.util.concurrent.CompletableFuture.wrapInCompletionException(CompletableFuture.java:325)
at java.base/java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:361)
at java.base/java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:366)
at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:695)
at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:529)
at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:507)
at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1394)
at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1970)
at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:187)
Caused by: java.lang.NullPointerException: Cannot invoke "org.eclipse.jdt.core.IMethod.getCompilationUnit()" because "iMethod" is null
at org.eclipse.jdt.internal.corext.refactoring.code.makestatic.InitialConditionsChecker.checkSourceAvailable(InitialConditionsChecker.java:181)
at org.eclipse.jdt.internal.corext.refactoring.code.MakeStaticRefactoring.checkInitialConditions(MakeStaticRefactoring.java:127)
at org.eclipse.jdt.ls.core.internal.corrections.RefactorProcessor.getMakeMethodStaticRefactoringProposal(RefactorProcessor.java:1189)
at org.eclipse.jdt.ls.core.internal.corrections.RefactorProcessor.getProposals(RefactorProcessor.java:228)
at org.eclipse.jdt.ls.core.internal.handlers.CodeActionHandler.getCodeActionCommands(CodeActionHandler.java:221)
at org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$15(JDTLanguageServer.java:775)
at org.eclipse.jdt.ls.core.internal.BaseJDTLanguageServer.lambda$0(BaseJDTLanguageServer.java:87)
at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:692)
... 5 more

[rgrunber]

Thanks for trying out the javac support. Not sure to what extent this is related to the stacktrace as I've seen the same error in #4080 . Might just be a bug where some code triggers it. I'm not seeing the stacktrace, but I can confirm the behaviour.

Also, I didn't see it in your configuration but you need to be using a JRE 24 (latest released version) as the runtime that starts JDT-LS to use the javac support currently. This can be configured with java.jdt.ls.java.home.

.vscode/settings.json

{
    "java.jdt.ls.java.home": "~/.sdkman/candidates/java/24-tem/",
    "java.jdt.ls.javac.enabled": "on",
    "java.completion.engine": "dom"
}

TestModel.java

package org.example;

import lombok.Getter;
import lombok.Setter;
import lombok.ToString;

@Getter
@Setter
@ToString
public class TestModel {
    private String name;
    private Integer age;

    public void test() {
        TestModel testModel = new TestModel();
        testModel.setAge(1);
        System.out.println(testModel);
    }
}

TestJ.java

package org.example;

public class TestJ {
    public void test() {
        TestModel testModel = new TestModel();
        testModel.setAge(3);
        testModel.setName("name");
        System.out.println(testModel);
    }
}

and then just make sure you have the Lombok jar on ./lib/lombok-1.18.39-4050.jar (from latest vscode-java) to ensure Lombok gets detected on the classpath.

TestModel.java works just fine, but TestJ.java shows the following :

Works just fine with the javac settings disabled. CC'ing @datho7561 in case this is of any interest on the javac side.