我一直试图搬到Gradle一段时间了。我要做的一件事就是根据通常添加的内容在WAR文件中自动创建其他条目。出于性能和其他原因，我试图通过在War任务的自定义子类中自动执行此操作来完成此操作。因为我必须解决私有可见性和最终字段，这不是我想要的那么好，但它在启动之前就失败了。当我从org.apache.tools.zip包中添加对类的引用时，构建在运行时失败，并带有以下堆栈跟踪：
17:44:32.888 [ERROR] [org.gradle.BuildExceptionReporter] FAILURE: Build failed with an exception.
17:44:32.900 [ERROR] [org.gradle.BuildExceptionReporter]
17:44:32.907 [ERROR] [org.gradle.BuildExceptionReporter] * Where:
17:44:32.914 [ERROR] [org.gradle.BuildExceptionReporter] Build file '...\build.gradle' line: 92
17:44:32.921 [ERROR] [org.gradle.BuildExceptionReporter]
17:44:32.928 [ERROR] [org.gradle.BuildExceptionReporter] * What went wrong:
17:44:32.935 [ERROR] [org.gradle.BuildExceptionReporter] A problem occurred evaluating root project '...'.
17:44:32.942 [ERROR] [org.gradle.BuildExceptionReporter] > Could not generate a proxy class for class ....ProblemWarTask.
17:44:32.953 [ERROR] [org.gradle.BuildExceptionReporter]
17:44:32.960 [ERROR] [org.gradle.BuildExceptionReporter] * Exception is:
17:44:32.969 [ERROR] [org.gradle.BuildExceptionReporter] org.gradle.api.GradleScriptException: A problem occurred evaluating root project '...'.
17:44:32.976 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.groovy.scripts.internal.DefaultScriptRunnerFactory$ScriptRunnerImpl.run(DefaultScriptRunnerFactory.java:54)
17:44:32.983 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.configuration.DefaultScriptPluginFactory$ScriptPluginImpl.apply(DefaultScriptPluginFactory.java:127)
17:44:32.991 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.configuration.BuildScriptProcessor.evaluate(BuildScriptProcessor.java:38)
17:44:32.998 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.configuration.LifecycleProjectEvaluator.evaluate(LifecycleProjectEvaluator.java:44)
17:44:33.005 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.project.AbstractProject.evaluate(AbstractProject.java:464)
17:44:33.013 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.project.AbstractProject.evaluate(AbstractProject.java:77)
17:44:33.020 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.configuration.DefaultBuildConfigurer$ConfigureProject.execute(DefaultBuildConfigurer.java:38)
17:44:33.027 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.configuration.DefaultBuildConfigurer$ConfigureProject.execute(DefaultBuildConfigurer.java:36)
17:44:33.034 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.project.AbstractProject.configure(AbstractProject.java:440)
17:44:33.041 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.project.AbstractProject.allprojects(AbstractProject.java:435)
17:44:33.048 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.configuration.DefaultBuildConfigurer.configure(DefaultBuildConfigurer.java:32)
17:44:33.055 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:142)
17:44:33.062 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:113)
17:44:33.069 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:81)
17:44:33.077 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:38)
17:44:33.086 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.exec.InProcessGradleLauncherActionExecuter.execute(InProcessGradleLauncherActionExecuter.java:39)
17:44:33.095 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.exec.InProcessGradleLauncherActionExecuter.execute(InProcessGradleLauncherActionExecuter.java:25)
17:44:33.103 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:50)
17:44:33.112 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.Actions$RunnableActionAdapter.execute(Actions.java:171)
17:44:33.121 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:201)
17:44:33.130 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:174)
17:44:33.139 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:170)
17:44:33.148 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:139)
17:44:33.157 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:33)
17:44:33.166 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:22)
17:44:33.175 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.Main.doAction(Main.java:48)
17:44:33.182 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45)
17:44:33.190 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.Main.main(Main.java:39)
17:44:33.197 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBootstrap.java:50)
17:44:33.206 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.java:32)
17:44:33.216 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.launcher.GradleMain.main(GradleMain.java:26)
17:44:33.227 [ERROR] [org.gradle.BuildExceptionReporter] Caused by: org.gradle.api.GradleException: Could not generate a proxy class for class ....ProblemWarTask.
17:44:33.238 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.AbstractClassGenerator.generate(AbstractClassGenerator.java:201)
17:44:33.249 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.project.taskfactory.TaskFactory.createTaskObject(TaskFactory.java:105)
17:44:33.258 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.project.taskfactory.TaskFactory.createTask(TaskFactory.java:70)
17:44:33.266 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory.createTask(AnnotationProcessingTaskFactory.java:93)
17:44:33.276 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.project.taskfactory.DependencyAutoWireTaskFactory.createTask(DependencyAutoWireTaskFactory.java:39)
17:44:33.285 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.tasks.DefaultTaskContainer.add(DefaultTaskContainer.java:56)
17:44:33.294 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.project.AbstractProject.task(AbstractProject.java:921)
17:44:33.301 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.BeanDynamicObject$MetaClassAdapter.invokeMethod(BeanDynamicObject.java:216)
17:44:33.311 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.BeanDynamicObject.invokeMethod(BeanDynamicObject.java:122)
17:44:33.319 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.CompositeDynamicObject.invokeMethod(CompositeDynamicObject.java:147)
17:44:33.328 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.groovy.scripts.BasicScript.methodMissing(BasicScript.java:83)
17:44:33.335 [ERROR] [org.gradle.BuildExceptionReporter] at build_77lv568h8hqtuhsa63froq7bcr.run(...\build.gradle:92)
17:44:33.343 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.groovy.scripts.internal.DefaultScriptRunnerFactory$ScriptRunnerImpl.run(DefaultScriptRunnerFactory.java:52)
17:44:33.352 [ERROR] [org.gradle.BuildExceptionReporter] ... 30 more
17:44:33.362 [ERROR] [org.gradle.BuildExceptionReporter] Caused by: java.lang.NoClassDefFoundError: Lorg/apache/tools/zip/ZipOutputStream;
17:44:33.370 [ERROR] [org.gradle.BuildExceptionReporter] at org.gradle.api.internal.AbstractClassGenerator.generate(AbstractClassGenerator.java:100)
17:44:33.379 [ERROR] [org.gradle.BuildExceptionReporter] ... 42 more
17:44:33.387 [ERROR] [org.gradle.BuildExceptionReporter] Caused by: java.lang.ClassNotFoundException: org.apache.tools.zip.ZipOutputStream
17:44:33.395 [ERROR] [org.gradle.BuildExceptionReporter] ... 43 more
17:44:33.403 [ERROR] [org.gradle.BuildExceptionReporter]
17:44:33.411 [LIFECYCLE] [org.gradle.BuildResultLogger]
17:44:33.419 [LIFECYCLE] [org.gradle.BuildResultLogger] BUILD FAILED
这仍然主要是学习Gradle。我现在最大的问题实际上是不理解为什么会发生这种情况以及我一般都缺少什么（例如，当我写其他任务时）。为什么这会很好地通过编译阶段（buildSrc.jar创建得很好）但是在运行时失败了？
这里有一个稍微混淆的源代码（你会发现它主要是Gradle自己代码的副本 - 即Zip任务）：
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.lang.reflect.Constructor;
import org.apache.tools.zip.UnixStat;
import org.apache.tools.zip.ZipEntry;
import org.apache.tools.zip.ZipOutputStream;
import org.gradle.api.file.FileVisitDetails;
import org.gradle.api.GradleException;
import org.gradle.api.internal.file.archive.ZipCopyAction;
import org.gradle.api.internal.file.archive.ZipCopySpecVisitor;
import org.gradle.api.internal.file.copy.CopyAction;
import org.gradle.api.internal.file.copy.CopyActionImpl;
import org.gradle.api.internal.file.copy.CopySpecImpl;
import org.gradle.api.internal.file.copy.CopySpecVisitor;
import org.gradle.api.internal.file.copy.MappingCopySpecVisitor;
import org.gradle.api.internal.file.copy.NormalizingCopySpecVisitor;
import org.gradle.api.internal.file.copy.ReadableCopySpec;
import org.gradle.api.internal.file.copy.ZipCompressor;
import org.gradle.api.internal.file.copy.ZipDeflatedCompressor;
import org.gradle.api.internal.file.FileResolver;
import org.gradle.api.tasks.bundling.War;
import org.gradle.api.tasks.bundling.Zip;
import org.gradle.api.UncheckedIOException;
import org.gradle.internal.nativeplatform.filesystem.FileSystems;
class ProblemWarTask extends War {
private ZipCopyActionImpl copyAction = null;
public ProblemWarTask() {}
protected synchronized Zip.ZipCopyActionImpl getCopyAction() {
if (copyAction == null) {
copyAction = new ProblemWarCopyActionImpl(getServices().get(FileResolver.class));
}
return copyAction;
}
protected class ProblemWarCopyActionImpl extends Zip.ZipCopyActionImpl {
private final CopySpecVisitor visitor;
public ProblemWarCopyActionImpl(FileResolver fileResolver) {
super((FileResolver) fileResolver);
visitor = new MappingCopySpecVisitor(new NormalizingCopySpecVisitor(new ProblemWarCopySpecVisitor()), FileSystems.getDefault());
}
public void execute() {
visitor.startVisit(this);
for (ReadableCopySpec spec : getRootSpec().getAllSpecs()) {
visitor.visitSpec(spec);
spec.getSource().visit(visitor);
}
visitor.endVisit();
}
public boolean getDidWork() {
return visitor.getDidWork();
}
}
protected class ProblemWarCopySpecVisitor extends ZipCopySpecVisitor {
private ZipOutputStream zipOutStr;
private File zipFile;
public void startVisit(CopyAction action) {
ZipCopyAction archiveAction = (ZipCopyAction) action;
zipFile = archiveAction.getArchivePath();
try {
zipOutStr = archiveAction.getCompressor().createArchiveOutputStream(zipFile);
} catch (Exception e) {
throw new GradleException(String.format("Could not create ZIP '%s'.", zipFile), e);
}
}
public void endVisit() {
try {
zipOutStr.close();
} catch (IOException e) {
throw new UncheckedIOException(e);
} finally {
zipOutStr = null;
}
}
public void visitFile(FileVisitDetails fileDetails) {
try {
ZipEntry archiveEntry = new ZipEntry(fileDetails.getRelativePath().getPathString());
archiveEntry.setTime(fileDetails.getLastModified());
archiveEntry.setUnixMode(UnixStat.FILE_FLAG | fileDetails.getMode());
zipOutStr.putNextEntry(archiveEntry);
fileDetails.copyTo(zipOutStr);
zipOutStr.closeEntry();
} catch (Exception e) {
throw new GradleException(String.format("Could not add %s to ZIP '%s'.", fileDetails, zipFile), e);
}
// Now do a little more - add stuff
try {
if (...) {
byte[] buffer;
...
ZipEntry archiveEntry = new ZipEntry(secondPath);
archiveEntry.setTime(fileDetails.getLastModified());
archiveEntry.setUnixMode(UnixStat.FILE_FLAG | fileDetails.getMode());
zipOutStr.putNextEntry(archiveEntry);
zipOutStr.write(buffer, 0, buffer.length);
zipOutStr.closeEntry();
}
} catch (Exception e) {
throw new GradleException(String.format("Could not add secondary form of %s to ZIP '%s'.", fileDetails, zipFile), e);
}
}
public void visitDir(FileVisitDetails dirDetails) {
try {
// Trailing slash in name indicates that entry is a directory
ZipEntry archiveEntry = new ZipEntry(dirDetails.getRelativePath().getPathString() + '/');
archiveEntry.setTime(dirDetails.getLastModified());
archiveEntry.setUnixMode(UnixStat.DIR_FLAG | dirDetails.getMode());
zipOutStr.putNextEntry(archiveEntry);
zipOutStr.closeEntry();
} catch (Exception e) {
throw new GradleException(String.format("Could not add %s to ZIP '%s'.", dirDetails, zipFile), e);
}
}
}
}
目前，构建脚本本身没有做任何特殊的事情：
task war(type: ....ProblemWarTask) {
...
}
身体与我用于“战争”的身体相同。任务，甚至是最初的实验（ProblemWarTask）。当我添加对所指出的包的引用时，异常开始发生。让我感到困扰的是，战争是怎样的？任务运行时运行得很好，因为它最终具有与此相同的运行时依赖性集。
这是Gradle 1.5。我也尝试将以下内容添加到build.gradle但没有帮助（同样的错误）：
buildscript {
dependencies {
classpath files(".../gradle/lib/ant-1.8.4.jar")
}
}
编辑 - 尝试使用Gradle 1.6，无需更改。发表于Gradle论坛：
编辑2 - 可在以下位置找到隔离的样本文件：
答案 0 :(得分：2)
War之类的任务类型并非设计为由用户创建子类。通过编写插件（在最简单的情况下，只是使用apply from: "path/to/script.gradle"应用的另一个构建脚本），使用其公共API预配置任务，而不是子类化和使用大量内部构件，而不是更好（更容易）。例如：
tasks.withType(War) {
eachFile { FileCopyDetails details -> ... }
}
如果绝对必要，这样的配置也可以进入子类的构造函数。
那就是说，我不确定你为什么要用Ant类来解决类加载器问题。如果您可以在http://forums.gradle.org提交一个自包含的可重现示例的问题，我们将会看一下。