Cannot use winzip to unzip the zip file zipped by java.util.zip

Question

Hi all,
I use the followcode to create a zip file, and i downlaod it and try to use winzip to unzip this file but fail. The path is correct and i got the zip file. but it just cannot unzip.
pls help
thanks alot.
Kin
          int count = 0;
          count = ContentDocuments.size();
          for (int i = 0; i < bb; i++)     {
               System.out.println(filenames[i] + "");
          // Create a buffer for reading the files
          byte[] buf = new byte[10*1024*1024];
          try {      
               String outFilename = MyDir + "zipfile/" + getContentID2()+".zip";
               System.out.println("outFilename = " + outFilename);
               ZipOutputStream out = new ZipOutputStream(new FileOutputStream(outFilename));
               for (int i=0; i<filenames.length; i++) {           
                    FileInputStream in = new FileInputStream(filenames);
                    out.putNextEntry(new ZipEntry(filenames[i]));
                    int len;
                    while ((len = in.read(buf)) != -1) {               
                         out.write(buf, 0, len);
                    out.closeEntry();
                    in.close();
               out.close();
          } catch (IOException e)     {
               System.err.println("zipprocess " + e.getMessage());

Answer 1

I've written a replacement zip file creator class. Not much tested but it seems to work, however I've yet to try it with the version of WINZIP that rejected my previous attempts. Oh, and the stored dates are garbage.
* ZipOutputFile.java
* Created on 25 March 2004, 13:08
package zip;
import java.io.IOException;
import java.nio.ByteBuffer;
* <p>Creates a ZIP archive in a file which WINZIP should be able to read.</p>
* <p>Unfortunately zip archives generated by the standard Java class
* {@link java.util.zip.ZipOutputStream}, while adhering to PKZIPs format specification,
* don't appear to be readable by some versions of WinZip and similar utilities. This is
* probably because they use
* a format specified for writing to a non-seakable stream, where the length and CRC of
* a file is writen to a special block following the data. Since the length of the binary
* date is unknown this makes an archive quite complicated to read, and it looks like
* WinZip hasn't bothered.</p>
* <p>All data is Deflated. Close completes the archive, flush terminates the current entry.</p>
* @see java.util.zip.ZipOutputStream
* @author  Malcolm McMahon
public class ZipOutputFile extends java.io.OutputStream {
    byte[] oneByte = new byte[1];
    java.io.RandomAccessFile archive;
    public final static short DEFLATE_METHOD = 8;
    public final static short VERSION_CODE = 20;
    public final static short MIN_VERSION = 10;
    public final static int  ENTRY_HEADER_MAGIC = 0x04034b50;
    public final static int  CATALOG_HEADER_MAGIC = 0x02014b50;
    public final static int  CATALOG_END_MAGIC = 0x06054b50;
    private final static short DISC_NUMBER = 0;
    ByteBuffer entryHeader = ByteBuffer.wrap(new byte[30]);
    ByteBuffer entryLater = ByteBuffer.wrap(new byte[12]);
    java.util.zip.CRC32 crcAcc = new java.util.zip.CRC32();
    java.util.zip.Deflater def = new java.util.zip.Deflater(java.util.zip.Deflater.DEFLATED, true);
    int totalCompressed;
    long MSEPOCH;
    byte [] deflateBuf = new byte[2048];
    public static final long SECONDS_TO_DAYS = 60 * 60 * 24;
     * Entry stores info about each file stored
    private class Entry {
        long offset;        // position of header in file
        byte[] name;
        long crc;
        int compressedSize;
        int uncompressedSize;
        java.util.Date date;
         * Contructor also writes initial header.
         * @param fileName Name under which data is stored.
         * @param date  Date to label the file with
         * @TODO get the date stored properly
        public Entry(String fileName, java.util.Date date) throws IOException {
            name = fileName.getBytes();
            this.date = date == null ? new java.util.Date() : date;
            entryHeader.position(10);
            putDate(entryHeader);
            entryHeader.putShort(26, (short)name.length);
            offset = archive.getFilePointer();
            archive.write(entryHeader.array());
            archive.write(name);
            catalog.add(this);
            crcAcc.reset();
            totalCompressed = 0;
            def.reset();
         * Finish writing entry data. Save the lenghts & crc for catalog
         * and go back and fill them in in the entry header.
        public void close() throws IOException {
            def.finish();
            while(!def.finished())
                deflate();
            entryLater.position(0);
            crc = crcAcc.getValue();
            compressedSize = totalCompressed;
            uncompressedSize = def.getTotalIn();
            entryLater.putInt((int)crc);
            entryLater.putInt(compressedSize);
            entryLater.putInt(uncompressedSize);
            long eof = archive.getFilePointer();
            archive.seek(offset + 14);
            archive.write(entryLater.array());
            archive.seek(eof);
         * Write the catalog data relevant to this entry. Buffer is
         * preloaded with fixed data.
         * @param buf Buffer to organise fixed lenght part of header
        public void writeCatalog(ByteBuffer buf) throws IOException {
            buf.position(12);
            putDate(buf);
            buf.putInt((int)crc);
            buf.putInt(compressedSize);
            buf.putInt(uncompressedSize);
            buf.putShort((short)name.length);
            buf.putShort((short)0);  // extra field length
            buf.putShort((short)0);  // file comment length
            buf.putShort(DISC_NUMBER);  // disk number
            buf.putShort((short)0); // internal attributes
            buf.putInt(0);      // external file attributes
            buf.putInt((int)offset); // file position
            archive.write(buf.array());
            archive.write(name);
         * This writes the entries date in MSDOS format.
         * @param buf Where to write it
         * @TODO Get this generating sane dates
        public void putDate(ByteBuffer buf) {
            long msTime = (date.getTime() - MSEPOCH) / 1000;
            buf.putShort((short)(msTime % SECONDS_TO_DAYS));
            buf.putShort((short)(msTime / SECONDS_TO_DAYS));
    private Entry entryInProgress = null; // entry currently being written
    private java.util.ArrayList catalog = new java.util.ArrayList(12);  // all entries
     * Start a new output file.
     * @param name The name to store as
     * @param date Date - null indicates current time
    public java.io.OutputStream openEntry(String name, java.util.Date date) throws IOException{
        if(entryInProgress != null)
            entryInProgress.close();
        entryInProgress = new Entry(name, date);
        return this;
     * Creates a new instance of ZipOutputFile
     * @param fd The file to write to
    public ZipOutputFile(java.io.File fd) throws IOException {
        this(new java.io.RandomAccessFile(fd, "rw"));
     * Create new instance of ZipOutputFile from RandomAccessFile
     * @param archive RandomAccessFile
    public ZipOutputFile(java.io.RandomAccessFile archive) {
        this.archive = archive;
        entryHeader.order(java.nio.ByteOrder.LITTLE_ENDIAN);  // create fixed fields of header
        entryLater.order(java.nio.ByteOrder.LITTLE_ENDIAN);
        entryHeader.putInt(ENTRY_HEADER_MAGIC);
        entryHeader.putShort(MIN_VERSION);
        entryHeader.putShort((short)0);  // general purpose flag
        entryHeader.putShort(DEFLATE_METHOD);
        java.util.Calendar cal = java.util.Calendar.getInstance();
        cal.clear();
        cal.set(java.util.Calendar.YEAR, 1950);
        cal.set(java.util.Calendar.DAY_OF_MONTH, 1);
//        def.setStrategy(Deflater.HUFFMAN_ONLY);
        MSEPOCH = cal.getTimeInMillis();
     * Writes the master catalogue and postamble and closes the archive file.
    public void close() throws IOException{
        if(entryInProgress != null)
            entryInProgress.close();
        ByteBuffer catEntry = ByteBuffer.wrap(new byte[46]);
        catEntry.order(java.nio.ByteOrder.LITTLE_ENDIAN);
        catEntry.putInt(CATALOG_HEADER_MAGIC);
        catEntry.putShort(VERSION_CODE);
        catEntry.putShort(MIN_VERSION);
        catEntry.putShort((short)0);
        catEntry.putShort(DEFLATE_METHOD);
        long catStart = archive.getFilePointer();
        for(java.util.Iterator it = catalog.iterator(); it.hasNext();) {
            ((Entry)it.next()).writeCatalog(catEntry);
        catEntry.position(0);
        catEntry.putInt(CATALOG_END_MAGIC);
        catEntry.putShort(DISC_NUMBER);
        catEntry.putShort(DISC_NUMBER);
        catEntry.putShort((short)catalog.size());
        catEntry.putShort((short)catalog.size());
        catEntry.putInt((int)(archive.getFilePointer() - catStart));
        catEntry.putInt((int)catStart);
        catEntry.putShort((short)0);
        archive.write(catEntry.array(), 0, catEntry.position());
        archive.setLength(archive.getFilePointer());  // truncate if old file
        archive.close();
        def.end();
     * Closes entry in progress.
    public void flush() throws IOException{
        if(entryInProgress == null)
            throw new IllegalStateException("Must call openEntry before writing");
        entryInProgress.close();
        entryInProgress = null;
     * Standard write routine. Defined by {@link java.io.OutputStream}.
     * Can only be used once openEntry has defined the file.
     * @param b  Bytes to write
    public void write(byte[] b) throws IOException{
        if(entryInProgress == null)
            throw new IllegalStateException("Must call openEntry before writing");
        crcAcc.update(b);
        def.setInput(b);
        while(!def.needsInput())
            deflate();
     * Standard write routine. Defined by {@link java.io.OutputStream}.
     * Can only be used once openEntry has defined the file.
     * @param b  Bytes to write
    public void write(int b) throws IOException{
        oneByte[0] = (byte)b;
        crcAcc.update(b);
        write(oneByte, 0, 1);
     *  Standard write routine. Defined by {@link java.io.OutputStream}.
     * Can only be used once openEntry has defined the file.
     * @param b  Bytes to write
     * @param off Start offset
     * @param len Byte count
    public void write(byte[] b, int off, int len) throws IOException{
        if(entryInProgress == null)
            throw new IllegalStateException("Must call openEntry before writing");
        crcAcc.update(b, off, len);
        def.setInput(b, off, len);
        while(!def.needsInput())
            deflate();
    * Gets a buffer full of coded data from the deflater and writes it to archive.
    private void deflate() throws IOException {
        int len = def.deflate(deflateBuf);
        totalCompressed += len;
        if(len > 0)
            archive.write(deflateBuf, 0, len);