ManifestModifier.java :  » IDE-Eclipse » pde » org » eclipse » pde » internal » build » tasks » Java Open Source

/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     IBM - Initial API and implementation
 *******************************************************************************/
package org.eclipse.pde.internal.build.tasks;

import java.io.*;
import java.util.*;
import java.util.jar.Attributes;
import java.util.jar.Manifest;
import java.util.jar.Attributes.Name;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Task;

/**
 * Internal task. 
 * Add, change or remove the keys from a manifest.mf.
 * @since 3.0 
 */
public class ManifestModifier extends Task {
  private String manifestLocation;
  private final Map newValues = new HashMap();
  private static String DELIM = "#|"; //$NON-NLS-1$
  private Manifest manifest = null;
  private boolean contentChanged = false;

  /**
   * Indicate new values to add to the manifest. The format of the parameter is key|value#key|value#...
   * If a value is specified to null, the key will be removed from the manifest. 
   * @param values
   */
  public void setKeyValue(String values) {
    StringTokenizer tokenizer = new StringTokenizer(values, DELIM, false);
    while (tokenizer.hasMoreElements()) {
      String key = tokenizer.nextToken();
      String value = tokenizer.nextToken();
      if (value.equals("null")) //$NON-NLS-1$
        value = null;
      newValues.put(key, value);
    }
  }

  public void execute() {
    loadManifest();

    applyChanges();

    writeManifest();
  }

  private void writeManifest() {
    if (!contentChanged)
      return;

    OutputStream os = null;
    try {
      os = new BufferedOutputStream(new FileOutputStream(manifestLocation));
      try {
        manifest.write(os);
        //work around bug 256787
        os.write(new byte[] {'\n'});
      } finally {
        os.close();
      }
    } catch (IOException e1) {
      new BuildException("Problem writing the content of the manifest : " + manifestLocation); //$NON-NLS-1$
    }
  }

  private void applyChanges() {
    for (Iterator iter = newValues.entrySet().iterator(); iter.hasNext();) {
      Map.Entry entry = (Map.Entry) iter.next();
      String key = (String) entry.getKey();
      String value = (String) entry.getValue();
      if (value == null) {
        removeAttribute(key);
      } else {
        changeValue(key, value);
      }
    }
    //force a manifest version if none exists
    if (!manifest.getMainAttributes().containsKey(Name.MANIFEST_VERSION)) {
      contentChanged = true;
      manifest.getMainAttributes().put(Name.MANIFEST_VERSION, "1.0"); //$NON-NLS-1$
    }

  }

  private void loadManifest() {
    try {
      //work around for bug 256787 
      InputStream is = new SequenceInputStream(new BufferedInputStream(new FileInputStream(manifestLocation)), new ByteArrayInputStream(new byte[] {'\n'}));
      try {
        manifest = new Manifest(is);
      } finally {
        is.close();
      }
    } catch (IOException e) {
      new BuildException("Problem reading the content of the manifest : " + manifestLocation); //$NON-NLS-1$
    }
  }

  private void changeValue(String key, String value) {
    Attributes attributes = manifest.getMainAttributes();
    if (attributes.containsKey(key) && attributes.getValue(key).equals(value))
      return;
    contentChanged = true;
    attributes.put(new Attributes.Name(key), value);
  }

  private void removeAttribute(String key) {
    contentChanged = true;
    manifest.getMainAttributes().remove(new Attributes.Name(key));
  }

  /**
   * 
   * @param path
   */
  public void setManifestLocation(String path) {
    manifestLocation = path;
  }
}