001    /* Manifest.java -- Reads, writes and manipulates jar manifest files
002       Copyright (C) 2000, 2004 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package java.util.jar;
039    
040    import gnu.java.util.jar.JarUtils;
041     
042    import java.io.IOException;
043    import java.io.InputStream;
044    import java.io.OutputStream;
045    import java.util.Hashtable;
046    import java.util.Map;
047    
048    /**
049     * Reads, writes and manipulaties jar manifest files.
050     * XXX
051     * 
052     * @since 1.2
053     * @author Mark Wielaard (mark@klomp.org)
054     */
055    public class Manifest implements Cloneable
056    {
057      // Fields
058    
059      /** The main attributes of the manifest (jar file). */
060      private final Attributes mainAttr;
061    
062      /** A map of atrributes for all entries described in this Manifest. */
063      private final Map<String, Attributes> entries;
064    
065      // Constructors
066    
067      /**
068       * Creates a new empty Manifest.
069       */
070      public Manifest()
071      {
072        mainAttr = new Attributes();
073        entries = new Hashtable<String, Attributes>();
074      }
075    
076      /**
077       * Creates a Manifest from the supplied input stream.
078       *
079       * @see #read(InputStream)
080       * @see #write(OutputStream)
081       *
082       * @param in the input stream to read the manifest from
083       * @exception IOException when an i/o exception occurs or the input stream
084       * does not describe a valid manifest
085       */
086      public Manifest(InputStream in) throws IOException
087      {
088        this();
089        read(in);
090      }
091    
092      /**
093       * Creates a Manifest from another Manifest.
094       * Makes a deep copy of the main attributes, but a shallow copy of
095       * the other entries. This means that you can freely add, change or remove
096       * the main attributes or the entries of the new manifest without effecting
097       * the original manifest, but adding, changing or removing attributes from
098       * a particular entry also changes the attributes of that entry in the
099       * original manifest.
100       *
101       * @see #clone()
102       * @param man the Manifest to copy from
103       */
104      public Manifest(Manifest man)
105      {
106        mainAttr = new Attributes(man.getMainAttributes());
107        entries = new Hashtable<String, Attributes>(man.getEntries());
108      }
109    
110      // Methods
111    
112      /**
113       * Gets the main attributes of this Manifest.
114       */
115      public Attributes getMainAttributes()
116      {
117        return mainAttr;
118      }
119    
120      /**
121       * Gets a map of entry Strings to Attributes for all the entries described
122       * in this manifest. Adding, changing or removing from this entries map
123       * changes the entries of this manifest.
124       */
125      public Map<String, Attributes> getEntries()
126      {
127        return entries;
128      }
129    
130      /**
131       * Returns the Attributes associated with the Entry.
132       * <p>
133       * Implemented as:
134       * <code>return (Attributes)getEntries().get(entryName)</code>
135       *
136       * @param entryName the name of the entry to look up
137       * @return the attributes associated with the entry or null when none
138       */
139      public Attributes getAttributes(String entryName)
140      {
141        return (Attributes) getEntries().get(entryName);
142      }
143    
144      /**
145       * Clears the main attributes and removes all the entries from the
146       * manifest.
147       */
148      public void clear()
149      {
150        mainAttr.clear();
151        entries.clear();
152      }
153    
154      /**
155       * Read and merge a <code>Manifest</code> from the designated input stream.
156       * 
157       * @param in the input stream to read from.
158       * @throws IOException if an I/O related exception occurs during the process.
159       */
160      public void read(InputStream in) throws IOException
161      {
162        JarUtils.readMFManifest(getMainAttributes(), getEntries(), in);
163      }
164    
165      /**
166       * Writes the contents of this <code>Manifest</code> to the designated
167       * output stream. Line-endings are platform-independent and consist of the
168       * 2-codepoint sequence <code>0x0D</code> and <code>0x0A</code>.
169       * 
170       * @param out the output stream to write this <code>Manifest</code> to.
171       * @throws IOException if an I/O related exception occurs during the process.
172       */
173      public void write(OutputStream out) throws IOException
174      {
175        JarUtils.writeMFManifest(getMainAttributes(), getEntries(), out);
176      }
177    
178      /**
179       * Makes a deep copy of the main attributes, but a shallow copy of
180       * the other entries. This means that you can freely add, change or remove
181       * the main attributes or the entries of the new manifest without effecting
182       * the original manifest, but adding, changing or removing attributes from
183       * a particular entry also changes the attributes of that entry in the
184       * original manifest. Calls <CODE>new Manifest(this)</CODE>.
185       */
186      public Object clone()
187      {
188        return new Manifest(this);
189      }
190    
191      /**
192       * Checks if another object is equal to this Manifest object.
193       * Another Object is equal to this Manifest object if it is an instance of
194       * Manifest and the main attributes and the entries of the other manifest
195       * are equal to this one.
196       */
197      public boolean equals(Object o)
198      {
199        return (o instanceof Manifest) &&
200          (mainAttr.equals(((Manifest) o).mainAttr)) &&
201          (entries.equals(((Manifest) o).entries));
202      }
203    
204      /**
205       * Calculates the hash code of the manifest. Implemented by a xor of the
206       * hash code of the main attributes with the hash code of the entries map.
207       */
208      public int hashCode()
209      {
210        return mainAttr.hashCode() ^ entries.hashCode();
211      }
212    
213    }