Gradle issue files: Custom gradle task extending the 'War' task does not see some required classes http://stackoverflow.com/questions/16408102/custom-gradle-task-extending-the-war-task-does-not-see-some-required-classes

build.gradle

// Just a standard War task
task okWar(type: War) {
  from("buildSrc")
  archiveName = "sample-ok.war"
}

// Custom subclass of War task that cannot find ZipOutputStream class in classpath
// Uncomment *after* you try others because nothing will work while this is here.
/*
task badWar(type: sample.ProblemWarTask) {
  from("buildSrc")
  archiveName = "sample-bad.war"
}
*/

// This is using a DummyWarTask which is the same ProblemWarTask with all references
// to missing classes removed (and, thus, won't actually create any wars, here just
// to illustrate that the classpath issue is restricted to those classes 
task dummyWar(type: sample.DummyWarTask) {
  from("buildSrc")
  archiveName = "sample-dummy.war"
}

buildSrc-src-main-java-sample-DummyWarCopySpecVisitor.java

package sample;

import org.gradle.api.GradleException;
import org.gradle.api.UncheckedIOException;

import org.gradle.api.tasks.bundling.War;
import org.gradle.api.tasks.bundling.Zip;

import org.gradle.api.internal.file.FileResolver;
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.ZipDeflatedCompressor;
import org.gradle.api.internal.file.copy.ZipCompressor;
import org.gradle.api.file.FileVisitDetails;

import org.gradle.api.internal.file.copy.MappingCopySpecVisitor;
import org.gradle.api.internal.file.copy.NormalizingCopySpecVisitor;
import org.gradle.api.internal.file.copy.CopySpecVisitor;
import org.gradle.api.internal.file.copy.ReadableCopySpec;

import org.gradle.internal.nativeplatform.filesystem.FileSystems;

import java.io.File;
import java.io.IOException;

public class DummyWarCopySpecVisitor extends ZipCopySpecVisitor {

  public void startVisit(CopyAction action) {
    // Do nothing - this a dummy
  }

  public void endVisit() {
    // Do nothing - this a dummy
  }

  public void visitFile(FileVisitDetails fileDetails) {
    // Do nothing - this a dummy
  }

  public void visitDir(FileVisitDetails dirDetails) {
    // Do nothing - this a dummy
  }
}

buildSrc-src-main-java-sample-DummyWarTask.java

package sample;

import org.gradle.api.GradleException;
import org.gradle.api.UncheckedIOException;

import org.gradle.api.tasks.bundling.War;
import org.gradle.api.tasks.bundling.Zip;

import org.gradle.api.internal.file.FileResolver;
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.ZipDeflatedCompressor;
import org.gradle.api.internal.file.copy.ZipCompressor;
import org.gradle.api.file.FileVisitDetails;

import org.gradle.api.internal.file.copy.MappingCopySpecVisitor;
import org.gradle.api.internal.file.copy.NormalizingCopySpecVisitor;
import org.gradle.api.internal.file.copy.CopySpecVisitor;
import org.gradle.api.internal.file.copy.ReadableCopySpec;

import org.gradle.internal.nativeplatform.filesystem.FileSystems;

import java.io.File;
import java.io.IOException;

class DummyWarTask extends War {

  private ZipCopyActionImpl copyAction = null;

  public DummyWarTask() {}

  protected synchronized Zip.ZipCopyActionImpl getCopyAction() {
    if (copyAction == null) {
      copyAction = new DummyWarCopyActionImpl(getServices().get(FileResolver.class));
    }
    return copyAction;
  }

  protected class DummyWarCopyActionImpl extends Zip.ZipCopyActionImpl {
    private final CopySpecVisitor visitor;
    
    public DummyWarCopyActionImpl(FileResolver fileResolver) {
      super((FileResolver) fileResolver);
      visitor = new MappingCopySpecVisitor(new NormalizingCopySpecVisitor(new DummyWarCopySpecVisitor()), 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();
    }
  }
}

buildSrc-src-main-java-sample-ProblemWarCopySpecVisitor.java

package sample;

import org.apache.tools.zip.ZipEntry;
import org.apache.tools.zip.ZipOutputStream;
import org.apache.tools.zip.UnixStat;
import org.gradle.api.GradleException;
import org.gradle.api.UncheckedIOException;

import org.gradle.api.tasks.bundling.War;
import org.gradle.api.tasks.bundling.Zip;

import org.gradle.api.internal.file.FileResolver;
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.ZipDeflatedCompressor;
import org.gradle.api.internal.file.copy.ZipCompressor;
import org.gradle.api.file.FileVisitDetails;

import org.gradle.api.internal.file.copy.MappingCopySpecVisitor;
import org.gradle.api.internal.file.copy.NormalizingCopySpecVisitor;
import org.gradle.api.internal.file.copy.CopySpecVisitor;
import org.gradle.api.internal.file.copy.ReadableCopySpec;

import org.gradle.internal.nativeplatform.filesystem.FileSystems;

import java.io.File;
import java.io.IOException;

public class ProblemWarCopySpecVisitor extends ZipCopySpecVisitor {
  private ZipOutputStream zipOutStr;
  private File zipFile;

  public void startVisit(CopyAction action) {
    // Copy of code from ZipCopySpecVisitor.startVisit()
    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() {
    // Copy of code from ZipCopySpecVisitor.endVisit()
    try {
      zipOutStr.close();
    } catch (IOException e) {
      throw new UncheckedIOException(e);
    } finally {
      zipOutStr = null;
    }
  }

  public void visitFile(FileVisitDetails fileDetails) {
    // Copy of code from ZipCopySpecVisitor.visitFile()
    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);
    }
    // Other stuff from here not needed for the example
  }

  public void visitDir(FileVisitDetails dirDetails) {
    // Copy of code from ZipCopySpecVisitor.visitDir()
    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);
    }
  }
}

buildSrc-src-main-java-sample-ProblemWarTask.java

package sample;

import org.apache.tools.zip.ZipEntry;
import org.apache.tools.zip.ZipOutputStream;
import org.apache.tools.zip.UnixStat;
import org.gradle.api.GradleException;
import org.gradle.api.UncheckedIOException;

import org.gradle.api.tasks.bundling.War;
import org.gradle.api.tasks.bundling.Zip;

import org.gradle.api.internal.file.FileResolver;
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.ZipDeflatedCompressor;
import org.gradle.api.internal.file.copy.ZipCompressor;
import org.gradle.api.file.FileVisitDetails;

import org.gradle.api.internal.file.copy.MappingCopySpecVisitor;
import org.gradle.api.internal.file.copy.NormalizingCopySpecVisitor;
import org.gradle.api.internal.file.copy.CopySpecVisitor;
import org.gradle.api.internal.file.copy.ReadableCopySpec;

import org.gradle.internal.nativeplatform.filesystem.FileSystems;

import java.io.File;
import java.io.IOException;

import java.lang.reflect.Constructor;

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() {
      // Copy of code from CopyActionImpl.execute()
      visitor.startVisit(this);
      for (ReadableCopySpec spec : getRootSpec().getAllSpecs()) {
        visitor.visitSpec(spec);
        spec.getSource().visit(visitor);
      }
     visitor.endVisit();
    }

    public boolean getDidWork() {
        return visitor.getDidWork();
    }
  }
}