Integrate Drools with Maven2 is a worry~~

Is this Maven 1 or Maven 2? Maven 2 What steps will reproduce the problem? 1. Create a GWT project where mvn install works fine. 2. Add a reference in the POM to Drools dependencies: <dependency> <groupId>org.drools</groupId> <artifactId>drools-core</artifactId> <version>4.0.4</version> </dependency> <dependency> <groupId>org.drools</groupId> <artifactId>drools-compiler</artifactId> <version>4.0.4</version> </dependency> 3. mvn install now fails: Unable to parse module: com.google.gwt.user.User java.lang.NoSuchMethodError: org.eclipse.jdt.internal.compiler.CompilationResult .getErrors()[Lorg/eclipse/jdt/core/compiler/IProblem; at com.google.gwt.dev.jdt.AbstractCompiler$ICompilerRequestorImpl.accept Result(AbstractCompiler.java:213) at org.eclipse.jdt.internal.compiler.Compiler.compile (Compiler.java:417) at com.google.gwt.dev.jdt.AbstractCompiler$CompilerImpl.compile (Abstract Compiler.java:74) at com.google.gwt.dev.jdt.AbstractCompiler$CompilerImpl.compile (Abstract Compiler.java:162) at com.google.gwt.dev.jdt.AbstractCompiler$CompilerImpl.access$600 (Abstr actCompiler.java:61) at com.google.gwt.dev.jdt.AbstractCompiler.compile (AbstractCompiler.java :430) at com.google.gwt.dev.jdt.AstCompiler.getCompilationUnitDeclarations(Ast Compiler.java:117) at com.google.gwt.dev.jdt.TypeOracleBuilder.build (TypeOracleBuilder.java :354) at com.google.gwt.dev.cfg.ModuleDef.getTypeOracle (ModuleDef.java:294) at com.google.gwt.dev.GWTCompiler.distill(GWTCompiler.java:321) at com.google.gwt.dev.GWTCompiler.run(GWTCompiler.java:755) at com.google.gwt.dev.GWTCompiler.run(GWTCompiler.java:745) at com.google.gwt.dev.GWTCompiler.main(GWTCompiler.java:213) Exception in thread "main" java.lang.NoSuchMethodError: org.eclipse.jdt.internal .compiler.CompilationResult.getErrors() [Lorg/eclipse/jdt/core/compiler/IProblem; at com.google.gwt.dev.jdt.AbstractCompiler$ICompilerRequestorImpl.accept Result(AbstractCompiler.java:213) at org.eclipse.jdt.internal.compiler.Compiler.compile (Compiler.java:417) at com.google.gwt.dev.jdt.AbstractCompiler$CompilerImpl.compile (Abstract Compiler.java:74) at com.google.gwt.dev.jdt.AbstractCompiler$CompilerImpl.compile (Abstract Compiler.java:162) at com.google.gwt.dev.jdt.AbstractCompiler$CompilerImpl.access$600 (Abstr actCompiler.java:61) at com.google.gwt.dev.jdt.AbstractCompiler.compile (AbstractCompiler.java :430) at com.google.gwt.dev.jdt.AstCompiler.getCompilationUnitDeclarations(Ast Compiler.java:117) at com.google.gwt.dev.jdt.TypeOracleBuilder.build (TypeOracleBuilder.java :354) at com.google.gwt.dev.cfg.ModuleDef.getTypeOracle (ModuleDef.java:294) at com.google.gwt.dev.GWTCompiler.distill(GWTCompiler.java:321) at com.google.gwt.dev.GWTCompiler.run(GWTCompiler.java:755) at com.google.gwt.dev.GWTCompiler.run(GWTCompiler.java:745) at com.google.gwt.dev.GWTCompiler.main(GWTCompiler.java:213) What is the expected output? What do you see instead? I expect the build to still execute correctly. Instead I see an error report and the build fails. What version of the product are you using? On what operating system? <artifactId>maven-googlewebtoolkit2-plugin</artifactId> <version>2.0-beta6</version> GWT 1.4.61, on Windows Vista. Please provide any additional information below. [INFO] -------------------------------------------------------------------- ---- [ERROR] BUILD ERROR [INFO] -------------------------------------------------------------------- ---- [INFO] Exception attempting compile. Embedded error: Compilation failed. [INFO] -------------------------------------------------------------------- ---- [DEBUG] Trace org.apache.maven.lifecycle.LifecycleExecutionException: Exception attempting compile. at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals (DefaultLifecycleExecutor.java:564) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalWithLifecycl e(DefaultLifecycleExecutor.java:480) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal (DefaultLifecycleExecutor.java:459) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFai lures(DefaultLifecycleExecutor.java:311) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments (DefaultLifecycleExecutor.java:278) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute (DefaultLifecycleExecutor.java:143) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:334) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:125) at org.apache.maven.cli.MavenCli.main(MavenCli.java:280) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.codehaus.classworlds.Launcher.launchEnhanced (Launcher.java:315) at org.codehaus.classworlds.Launcher.launch(Launcher.java:255) at org.codehaus.classworlds.Launcher.mainWithExitCode (Launcher.java:430) at org.codehaus.classworlds.Launcher.main(Launcher.java:375) Caused by: org.apache.maven.plugin.MojoExecutionException: Exception attempting compile. at com.totsp.mavenplugin.gwt.CompileMojo.execute (CompileMojo.java:58) at org.apache.maven.plugin.DefaultPluginManager.executeMojo (DefaultPluginManager.java:443) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals (DefaultLifecycleExecutor.java:539) ... 16 more Caused by: org.apache.maven.plugin.MojoFailureException: Compilation failed. at com.totsp.mavenplugin.gwt.CompileMojo.execute (CompileMojo.java:55) ... 18 more

Comment 1 by kebernet, Jan 31, 2008 Can you not set drools-compiler <scope>runtime</scope>?

Comment 2 by skingaby, Feb 04, 2008 I was able to work around this by excluding the JDT from the Drools components: <dependency> <groupId>org.drools</groupId> <artifactId>drools-core</artifactId> <version>4.0.4</version> <exclusions> <exclusion> <groupId>org.eclipse.jdt</groupId> <artifactId>core</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.drools</groupId> <artifactId>drools-compiler</artifactId> <version>4.0.4</version> <exclusions> <exclusion> <groupId>org.eclipse.jdt</groupId> <artifactId>core</artifactId> </exclusion> </exclusions> </dependency>

Comment 3 by mirko.nasato, Aug 07, 2008 That's because gwt-dev.jar includes the org.eclipse.jdt classes, so you ended up with two different versions of JDT in your classpath. Ideally gwt-dev.jar should be repackaged to only include com.google.gwt classes, and declares other dependencies in its pom.xml like any good Maven citizen.

Comment 4 by charlie.collins, Sep 09, 2008 I added the workaround to the M2 FAQ - we aren't going to repackage GWT (the workaround seems sufficient)