New zip classes from Avalon excalibur.

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/io/trunk@140304 13f79535-47bb-0310-9956-ffa450edef68

Author: Nicola Ken Barozzi

src/java/org/apache/commons/io/compress/zip/AsiExtraField.java

@@ -0,0 +1,398 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.commons.io.compress.zip;
+
+import java.util.zip.CRC32;
+import java.util.zip.ZipException;
+
+/**
+ * Adds Unix file permission and UID/GID fields as well as symbolic link
+ * handling. <p>
+ *
+ * This class uses the ASi extra field in the format: <pre>
+ *         Value         Size            Description
+ *         -----         ----            -----------
+ * (Unix3) 0x756e        Short           tag for this extra block type
+ *         TSize         Short           total data size for this block
+ *         CRC           Long            CRC-32 of the remaining data
+ *         Mode          Short           file permissions
+ *         SizDev        Long            symlink'd size OR major/minor dev num
+ *         UID           Short           user ID
+ *         GID           Short           group ID
+ *         (var.)        variable        symbolic link filename
+ * </pre> taken from appnote.iz (Info-ZIP note, 981119) found at <a
+ * href="ftp://ftp.uu.net/pub/archiving/zip/doc/">
+ * ftp://ftp.uu.net/pub/archiving/zip/doc/</a> </p> <p>
+ *
+ * Short is two bytes and Long is four bytes in big endian byte and word order,
+ * device numbers are currently not supported.</p>
+ *
+ * @author <a href="stefan.bodewig@epost.de">Stefan Bodewig</a>
+ * @version $Revision: 1.1 $
+ */
+public class AsiExtraField
+    implements ZipExtraField, UnixStat, Cloneable
+{
+    private static final ZipShort HEADER_ID = new ZipShort( 0x756E );
+
+    /**
+     * Standard Unix stat(2) file mode.
+     *
+     * @since 1.1
+     */
+    private int m_mode;
+
+    /**
+     * User ID.
+     *
+     * @since 1.1
+     */
+    private int m_uid;
+
+    /**
+     * Group ID.
+     *
+     * @since 1.1
+     */
+    private int m_gid;
+
+    /**
+     * File this entry points to, if it is a symbolic link. <p>
+     *
+     * empty string - if entry is not a symbolic link.</p>
+     *
+     * @since 1.1
+     */
+    private String m_link = "";
+
+    /**
+     * Is this an entry for a directory?
+     *
+     * @since 1.1
+     */
+    private boolean m_dirFlag;
+
+    /**
+     * Instance used to calculate checksums.
+     *
+     * @since 1.1
+     */
+    private CRC32 m_crc = new CRC32();
+
+    /**
+     * Indicate whether this entry is a directory.
+     *
+     * @param dirFlag The new Directory value
+     * @since 1.1
+     */
+    public void setDirectory( final boolean dirFlag )
+    {
+        m_dirFlag = dirFlag;
+        m_mode = getMode( m_mode );
+    }
+
+    /**
+     * Set the group id.
+     *
+     * @param gid The new GroupId value
+     * @since 1.1
+     */
+    public void setGroupId( int gid )
+    {
+        m_gid = gid;
+    }
+
+    /**
+     * Indicate that this entry is a symbolic link to the given filename.
+     *
+     * @param name Name of the file this entry links to, empty String if it is
+     *      not a symbolic link.
+     * @since 1.1
+     */
+    public void setLinkedFile( final String name )
+    {
+        m_link = name;
+        m_mode = getMode( m_mode );
+    }
+
+    /**
+     * File mode of this file.
+     *
+     * @param mode The new Mode value
+     * @since 1.1
+     */
+    public void setMode( final int mode )
+    {
+        m_mode = getMode( mode );
+    }
+
+    /**
+     * Set the user id.
+     *
+     * @param uid The new UserId value
+     * @since 1.1
+     * @deprecated Use setUserID(int)
+     * @see #setUserID(int)
+     */
+    public void setUserId( final int uid )
+    {
+        m_uid = uid;
+    }
+
+    /**
+     * Set the user id.
+     *
+     * @param uid The new UserId value
+     */
+    public void setUserID( final int uid )
+    {
+        m_uid = uid;
+    }
+
+    /**
+     * Delegate to local file data.
+     *
+     * @return The CentralDirectoryData value
+     * @since 1.1
+     */
+    public byte[] getCentralDirectoryData()
+    {
+        return getLocalFileDataData();
+    }
+
+    /**
+     * Delegate to local file data.
+     *
+     * @return The CentralDirectoryLength value
+     * @since 1.1
+     */
+    public ZipShort getCentralDirectoryLength()
+    {
+        return getLocalFileDataLength();
+    }
+
+    /**
+     * Get the group id.
+     *
+     * @return The GroupId value
+     * @since 1.1
+     */
+    public int getGroupID()
+    {
+        return m_gid;
+    }
+
+    /**
+     * Get the group id.
+     *
+     * @return The GroupId value
+     * @since 1.1
+     * @deprecated Use getGroupID() instead
+     * @see #getGroupID()
+     */
+    public int getGroupId()
+    {
+        return m_gid;
+    }
+
+    /**
+     * The Header-ID.
+     *
+     * @return The HeaderId value
+     * @since 1.1
+     */
+    public ZipShort getHeaderID()
+    {
+        return HEADER_ID;
+    }
+
+    /**
+     * Name of linked file
+     *
+     * @return name of the file this entry links to if it is a symbolic link,
+     *      the empty string otherwise.
+     * @since 1.1
+     */
+    public String getLinkedFile()
+    {
+        return m_link;
+    }
+
+    /**
+     * The actual data to put into local file data - without Header-ID or length
+     * specifier.
+     *
+     * @return The LocalFileDataData value
+     * @since 1.1
+     */
+    public byte[] getLocalFileDataData()
+    {
+        // CRC will be added later
+        byte[] data = new byte[ getLocalFileDataLength().getValue() - 4 ];
+        System.arraycopy( ( new ZipShort( getMode() ) ).getBytes(), 0, data, 0, 2 );
+
+        byte[] linkArray = getLinkedFile().getBytes();
+        System.arraycopy( ( new ZipLong( linkArray.length ) ).getBytes(),
+                          0, data, 2, 4 );
+
+        System.arraycopy( ( new ZipShort( getUserID() ) ).getBytes(),
+                          0, data, 6, 2 );
+        System.arraycopy( ( new ZipShort( getGroupID() ) ).getBytes(),
+                          0, data, 8, 2 );
+
+        System.arraycopy( linkArray, 0, data, 10, linkArray.length );
+
+        m_crc.reset();
+        m_crc.update( data );
+        long checksum = m_crc.getValue();
+
+        byte[] result = new byte[ data.length + 4 ];
+        System.arraycopy( ( new ZipLong( checksum ) ).getBytes(), 0, result, 0, 4 );
+        System.arraycopy( data, 0, result, 4, data.length );
+        return result;
+    }
+
+    /**
+     * Length of the extra field in the local file data - without Header-ID or
+     * length specifier.
+     *
+     * @return The LocalFileDataLength value
+     * @since 1.1
+     */
+    public ZipShort getLocalFileDataLength()
+    {
+        return new ZipShort( 4 + // CRC
+                             2 + // Mode
+                             4 + // SizDev
+                             2 + // UID
+                             2 + // GID
+                             getLinkedFile().getBytes().length );
+    }
+
+    /**
+     * File mode of this file.
+     *
+     * @return The Mode value
+     * @since 1.1
+     */
+    public int getMode()
+    {
+        return m_mode;
+    }
+
+    /**
+     * Get the user id.
+     *
+     * @return The UserId value
+     * @since 1.1
+     * @deprecated Use getUserID()
+     * @see #getUserID()
+     */
+    public int getUserId()
+    {
+        return m_uid;
+    }
+
+    /**
+     * Get the user id.
+     *
+     * @return The UserID value
+     */
+    public int getUserID()
+    {
+        return m_uid;
+    }
+
+    /**
+     * Is this entry a directory?
+     *
+     * @return The Directory value
+     * @since 1.1
+     */
+    public boolean isDirectory()
+    {
+        return m_dirFlag && !isLink();
+    }
+
+    /**
+     * Is this entry a symbolic link?
+     *
+     * @return The Link value
+     * @since 1.1
+     */
+    public boolean isLink()
+    {
+        return getLinkedFile().length() != 0;
+    }
+
+    /**
+     * Populate data from this array as if it was in local file data.
+     *
+     * @param buffer the buffer
+     * @param offset the offset into buffer
+     * @param length the length of data in buffer
+     * @throws ZipException on error
+     * @since 1.1
+     */
+    public void parseFromLocalFileData( final byte[] buffer,
+                                        final int offset,
+                                        final int length )
+        throws ZipException
+    {
+
+        long givenChecksum = ( new ZipLong( buffer, offset ) ).getValue();
+        byte[] tmp = new byte[ length - 4 ];
+        System.arraycopy( buffer, offset + 4, tmp, 0, length - 4 );
+        m_crc.reset();
+        m_crc.update( tmp );
+        long realChecksum = m_crc.getValue();
+        if( givenChecksum != realChecksum )
+        {
+            throw new ZipException( "bad CRC checksum " + Long.toHexString( givenChecksum ) +
+                                    " instead of " + Long.toHexString( realChecksum ) );
+        }
+
+        int newMode = ( new ZipShort( tmp, 0 ) ).getValue();
+        byte[] linkArray = new byte[ (int)( new ZipLong( tmp, 2 ) ).getValue() ];
+        m_uid = ( new ZipShort( tmp, 6 ) ).getValue();
+        m_gid = ( new ZipShort( tmp, 8 ) ).getValue();
+
+        if( linkArray.length == 0 )
+        {
+            m_link = "";
+        }
+        else
+        {
+            System.arraycopy( tmp, 10, linkArray, 0, linkArray.length );
+            m_link = new String( linkArray );
+        }
+        setDirectory( ( newMode & DIR_FLAG ) != 0 );
+        setMode( newMode );
+    }
+
+    /**
+     * Get the file mode for given permissions with the correct file type.
+     *
+     * @param mode Description of Parameter
+     * @return The Mode value
+     * @since 1.1
+     */
+    protected int getMode( final int mode )
+    {
+        int type = FILE_FLAG;
+        if( isLink() )
+        {
+            type = LINK_FLAG;
+        }
+        else if( isDirectory() )
+        {
+            type = DIR_FLAG;
+        }
+        return type | ( mode & PERM_MASK );
+    }
+}