Groovy + Antbuilder: how to use Grape to work with taskdef?

Question

It's connected with. I am trying to dynamically add maven-ant -tasks jars using Grape, simulating this:

<taskdef uri="antlib:org.apache.maven.artifact.ant" resource="org/apache/maven/artifact/ant/antlib.xml" classpathref="ant.classpath" /> 

I tried using Grape.grab () to make maven-ant -tasks available to AntBuilder as follows:

 import groovy.grape.Grape println "grab..." Grape.grab(group:'ant', module:'ant', version:'1.7.0', classLoader:this.class.classLoader.rootLoader) Grape.grab(group: 'org.apache.maven', module: 'maven-ant-tasks', version: '2.0.9') println "ant taskdef..." def ant = new AntBuilder() ant.taskdef (resource: "org/apache/maven/artifact/ant/antlib.xml" ) 

but this does not work, because Grape adds modules to another ClassLoader from the one that uses the ANT engine. So, I took the advice of this question about the AntBuilder path object and made Grape to use the root class of ClassLoader:

 import groovy.grape.Grape println "grab..." Grape.grab(group:'ant', module:'ant', version:'1.7.0', classLoader:this.class.classLoader.rootLoader) Grape.grab(group: 'org.apache.maven', module: 'maven-ant-tasks', version: '2.0.9', classLoader: this.class.classLoader.rootLoader) println "ant taskdef..." def ant = new AntBuilder() ant.taskdef (resource: "org/apache/maven/artifact/ant/antlib.xml" ) 

Now it raises a LinkageError:

 Caught: : java.lang.LinkageError: loader constraint violation: when resolving overridden method "org.apache.tools.ant.helper.ProjectHelper2$RootHandler.setDocumentLocator(Lorg/xml/sax/Locator;)V" the class loader (instance of org/codehaus/groovy/tools/RootLoader) of the current class, org/apache/tools/ant/helper/ProjectHelper2$RootHandler, and its superclass loader (instance of <bootloader>), have different Class objects for the type org/xml/sax/Locator used in the signature at test.mavenanttasks.run(mavenanttasks.groovy:11) 

Any hints on getting this to work? Or is all this a bad idea?

Answer 1

I found this: http://groovy.codehaus.org/Using+Ant+Libraries+with+AntBuilder

First put maven-ant -tasks in the root class loader with:

 @Grapes([ @Grab(group = 'org.apache.maven', module = 'maven-ant-tasks', version = '2.1.3'), @GrabConfig(systemClassLoader = true) ]) 

Alternatively for older versions of Groovy:

 Grape.grab(group: 'org.apache.maven', module: 'maven-ant-tasks', version: '2.1.3', classLoader: this.class.classLoader.rootLoader) 

Maven ANT tasks are "AntLib" and they can be downloaded as follows:

 import groovy.xml.NamespaceBuilder def ant = new AntBuilder() def mvn = NamespaceBuilder.newInstance(ant, 'antlib:org.apache.maven.artifact.ant') 

Answer 2

We can create an ant path (class path) using java.net.URLClassLoader or its subclass for example:

 <!-- language: groovy --> @Grapes([ @Grab(group='org.jacoco', module='org.jacoco.ant', version= '0.7.4.201502262128'), @Grab(group='org.jacoco', module='org.jacoco.core', version= '0.7.4.201502262128'), @Grab('org.jacoco:org.jacoco.report:0.7.4.201502262128'), ]) class Tool { def dump(args){ println "do dump...:$args" println "DumpTask:"+org.jacoco.ant.DumpTask.classLoader; def ant = new AntBuilder(); def path1 = ant.path{ org.jacoco.ant.DumpTask.classLoader.getURLs().each { ant.pathelement(location:it.getFile()) } } println "path11:$path1"; // classname way // ant.taskdef(name:"dump",classname:"org.jacoco.ant.DumpTask",classpath:path1); // ant.dump(args); //namespace way ant.taskdef(uri:'antlib:org.jacoco.ant',resource:'org/jacoco/ant/antlib.xml',classpath:path1); def jacoco=groovy.xml.NamespaceBuilder.newInstance(ant, 'antlib:org.jacoco.ant') jacoco.dump(args); } }