Using Drools on Jetty

I am trying to start up a webapp that uses Drools 5.2.0.M1. I get the following stacktrace on startup:

java.lang.NoSuchMethodError: org.eclipse.jdt.internal.compiler.CompilationResult.getProblems()[Lorg/eclipse/jdt/core/compiler/CategorizedProblem;
at org.drools.commons.jci.compilers.EclipseJavaCompiler$3.acceptResult(EclipseJavaCompiler.java:336)
at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:335)
at org.drools.commons.jci.compilers.EclipseJavaCompiler.compile(EclipseJavaCompiler.java:366)
at org.drools.commons.jci.compilers.AbstractJavaCompiler.compile(AbstractJavaCompiler.java:51)
at org.drools.rule.builder.dialect.java.JavaDialect.compileAll(JavaDialect.java:366)
at org.drools.compiler.DialectCompiletimeRegist开发者_JS百科ry.compileAll(DialectCompiletimeRegistry.java:55)

I have the jars in my pom:

    <dependency>
        <groupId>org.drools</groupId>
        <artifactId>drools-compiler</artifactId>
        <version>5.2.0.M1</version>
    </dependency>
    <dependency>
        <groupId>org.eclipse.jdt.core.compiler</groupId>
        <artifactId>ecj</artifactId>
        <version>3.5.1</version>
    </dependency>

Why Can't it find CompilationResult.getProblems()?

JDT isn't backwards compatible. Check the drools-compiler pom (of exactly the version you're using) on which version of ecj it depends and use that version. Or don't declare ecj at all, it's a transitive dependency for drools-compiler anyway.

PS: upgrade to drools 5.2.0.CR1 (or final once it's out)

I had a similar problem. I was having a web-app using Jetty 6. Jetty 6 which apparently bringing in a non-compatible version of JDT. After switching to Jetty 7 the problem was solved.