Groovy与Grape和AntBuilder类加载器问题

Question

我想用groovy做一个小ftp脚本,发现这篇文章http://www.hhhhq.org/blog/2009/05/01/ftp-using-groovy-and-ant/ 因为有几个依赖我想要用葡萄.所有依赖项都已解析并存在于缓存中.但我无法让Ant在其他库中找到可选任务.它总是说

Caught: : Problem: failed to create task or type ftp
Cause: the class org.apache.tools.ant.taskdefs.optional.net.FTP was not found.
        This looks like one of Ant's optional components.
Action: Check that the appropriate optional JAR exists in
        -ANT_HOME\lib
        -the IDE Ant configuration dialogs

Do not panic, this is a common problem.
The commonest cause is a missing JAR.

This is not a bug; it is a configuration problem

        at GrabTest.runMe(GrabTest.groovy:15)
        at GrabTest.run(GrabTest.groovy:26)

Groovy版本:1.6.5 JVM:1.6.0_15

这是我的源代码

@Grab(group='ant', module='ant', version='[1.6.5,)')
@Grab(group='ant', module='ant-nodeps', version='[1.0,)')
@Grab(group='ant', module='ant-apache-oro', version='[1.0,)') 
@Grab(group='ant', module='ant-commons-net', version='[1.0,)') 
@Grab(group='apache-oro', module='jakarta-oro', version='[2.0.8,)')
@Grab(group='commons-net', module='commons-net', version='[1.4,)')
def runMe() {
    // works
    println getClass().getClassLoader().loadClass("org.apache.tools.ant.taskdefs.optional.net.FTP")

    def ant = new AntBuilder()

    println getClass().getClassLoader() //groovy.lang.GroovyClassLoader$InnerLoader
    println ant.getClass().getClassLoader() //org.codehaus.groovy.tools.RootLoader
    ant.ftp( server:"ftp.foo.com",
            userid:"user",
            password:"passwd",
            passive:"yes",
            verbose:"yes",
            remotedir:"/pub/incoming",
            binary:"yes" ) {
                fileset( dir:"." ) { include( name:"**/*.gz" ) }
            }
}

runMe()

正如你所看到的,我怀疑是类问题的类加载器,似乎Grape没有注入依赖项.知道如何让它工作？

Answer 1

您是否正确怀疑类加载器是问题的根源.正如您的代码已经揭示的那样,AntBuilder是从RootLoader加载的,它无法访问@Grab注释所加载的类.正如GROOVY-3730所示,Groovy 1.7将解决这个问题.

但是,您可以通过直接使用该groovy.grape.Grape.grab(Map dependency)方法来解决您的问题,您可以在其中设置应该用于加载依赖项的特定类加载器:

import groovy.grape.Grape;

Grape.grab(group:'ant', module:'ant', version:'1.6.5', classLoader:this.class.classLoader.rootLoader)
Grape.grab(group:'ant', module:'ant-nodeps', version:'1.6.5', classLoader:this.class.classLoader.rootLoader)
Grape.grab(group:'ant', module:'ant-apache-oro', version:'1.6.5', classLoader:this.class.classLoader.rootLoader)
Grape.grab(group:'ant', module:'ant-commons-net', version:'1.6.5', classLoader:this.class.classLoader.rootLoader)
Grape.grab(group:'commons-net', module:'commons-net', version:'1.4.1', classLoader:this.class.classLoader.rootLoader)
Grape.grab(group:'oro', module:'oro', version:'2.0.8', classLoader:this.class.classLoader.rootLoader)