在用 Grails 进行编译的时候出现下面的异常：Unable to start Grails: java.lang.reflect.InvocationTargetException如果你使用的 Ant 是 1.8 版的，你需要将版本回退到 1.7
Grails 目前还不支持 Ant 1.8 版。
根据官方的说明，Grails 目前只支持 1.7 版的 ANT。
请参考 Grail 官方网站的信息：
[url]http://jira.grails.org/browse/GRAILS-6897[/url]
错误栈信息如下：[code]BUILD FAILED
/Users/ildar/tmp/grails-ant-integration/build.xml:125: The following error occurred while executing this line:
/Users/ildar/tmp/grails-ant-integration/build.xml:48: Unable to start Grails: java.lang.reflect.InvocationTargetException
at grails.ant.GrailsTask.runGrails(GrailsTask.java:138)
at grails.ant.GrailsTask.execute(GrailsTask.java:99)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
at org.apache.tools.ant.Task.perform(Task.java:348)
at org.apache.tools.ant.taskdefs.Sequential.execute(Sequential.java:68)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
at org.apache.tools.ant.Task.perform(Task.java:348)
at org.apache.tools.ant.taskdefs.MacroInstance.execute(MacroInstance.java:398)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
at org.apache.tools.ant.Task.perform(Task.java:348)
at org.apache.tools.ant.Target.execute(Target.java:390)
at org.apache.tools.ant.Target.performTasks(Target.java:411)
at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1397)
at org.apache.tools.ant.Project.executeTarget(Project.java:1366)
at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
at org.apache.tools.ant.Project.executeTargets(Project.java:1249)
at org.apache.tools.ant.Main.runBuild(Main.java:801)
at org.apache.tools.ant.Main.startAnt(Main.java:218)
at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280)
at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)
Caused by: java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at org.codehaus.groovy.grails.cli.support.GrailsBuildHelper.execute(GrailsBuildHelper.java:105)
at grails.ant.GrailsTask.runGrails(GrailsTask.java:127)
… 31 more
Caused by: java.lang.reflect.InvocationTargetException
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.groovy.grails.cli.support.GrailsBuildHelper.execute(GrailsBuildHelper.java:99)
… 32 more
Caused by: : The following error occurred while executing this line:
jar:file:/usr/share/ant/lib/ant.jar!/org/apache/tools/ant/antlib.xml:37: Problem: failed to create task or type componentdef
Cause: The name is undefined.
Action: Check the spelling.
Action: Check that any custom tasks/types have been declared.
Action: Check that any / declarations have taken place.
at org.apache.tools.ant.ProjectHelper.addLocationToBuildException(ProjectHelper.java:508)
at org.apache.tools.ant.taskdefs.Definer.loadAntlib(Definer.java:434)
at org.apache.tools.ant.taskdefs.Definer.execute(Definer.java:281)
at org.apache.tools.ant.ComponentHelper.checkNamespace(ComponentHelper.java:790)
at org.apache.tools.ant.ComponentHelper.getDefinition(ComponentHelper.java:260)
at org.apache.tools.ant.ComponentHelper.createComponent(ComponentHelper.java:237)
at org.apache.tools.ant.ComponentHelper.createComponent(ComponentHelper.java:216)
at org.apache.tools.ant.UnknownElement.makeObject(UnknownElement.java:414)
at org.apache.tools.ant.UnknownElement.maybeConfigure(UnknownElement.java:160)
at groovy.util.AntBuilder.performTask(AntBuilder.java:245)
at groovy.util.AntBuilder.nodeCompleted(AntBuilder.java:212)
at groovy.util.BuilderSupport.doInvokeMethod(BuilderSupport.java:147)
at groovy.util.AntBuilder.doInvokeMethod(AntBuilder.java:166)
at groovy.util.BuilderSupport.invokeMethod(BuilderSupport.java:64)
at org.codehaus.gant.GantBuilder.invokeMethod(GantBuilder.java:93)
at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:45)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:40)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:124)
at org.codehaus.gant.GantBinding.initializeGantBinding(GantBinding.groovy:108)
at org.codehaus.gant.GantBinding.this$4$initializeGantBinding(GantBinding.groovy)
at org.codehaus.gant.GantBinding$this$4$initializeGantBinding.callCurrent(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallCurrent(CallSiteArray.java:44)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:141)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:145)
at org.codehaus.gant.GantBinding.(GantBinding.groovy:42)
at org.codehaus.groovy.grails.cli.GrailsScriptRunner.callPluginOrGrailsScript(GrailsScriptRunner.java:436)
at org.codehaus.groovy.grails.cli.GrailsScriptRunner.executeCommand(GrailsScriptRunner.java:308)
at org.codehaus.groovy.grails.cli.GrailsScriptRunner.executeCommand(GrailsScriptRunner.java:243)
… 37 more
Caused by: jar:file:/usr/share/ant/lib/ant.jar!/org/apache/tools/ant/antlib.xml:37: Problem: failed to create task or type componentdef
Cause: The name is undefined.
Action: Check the spelling.
Action: Check that any custom tasks/types have been declared.
Action: Check that any / declarations have taken place.
at org.apache.tools.ant.UnknownElement.getNotFoundException(UnknownElement.java:484)
at org.apache.tools.ant.UnknownElement.makeObject(UnknownElement.java:416)
at org.apache.tools.ant.UnknownElement.maybeConfigure(UnknownElement.java:160)
at org.apache.tools.ant.taskdefs.Antlib.execute(Antlib.java:146)
at org.apache.tools.ant.taskdefs.Definer.loadAntlib(Definer.java:432)
… 64 more[/code]