使用 jzlib 创建 gzip 文件

Question

我正在尝试使用开源的 jzlib 创建 gzip 文件。 Java GZIPOutputStream 有点问题，CPU 变高了却一直没有释放。

JZlib的问题是winrar无法打开文件，看起来像是缺少标头。知道如何解决吗？

Answer 1

从JZlib 1.1.0开始，它支持gzip文件格式。
尝试 com.jcraft.jzlib。 GZIPOutputStream 类

Answer 2

这是该课程的略读版本；希望它能发挥作用。
这个版本仍然保留了正确的flush()实现。

原始版本对内存内进程进行了优化（希望在删除某些部分后它仍然有效）。源代码包含来自 Apache 的 CRC32 以及对许可证的适当通知。

package bestsss.util;


import java.io.EOFException;
import java.io.IOException;
import java.io.OutputStream;
import java.util.zip.Deflater;

import com.jcraft.jzlib.JZlib;
import com.jcraft.jzlib.ZStream;

import java.util.zip.Checksum;
/**
 * GZipOutputStream replacement, faster than optimized (not any more here)
 * @author XXX XXX
 *
 */
public class JGZipOutputStream extends OutputStream{
  /*
   * GZIP header magic number.
   */
  private final static int GZIP_MAGIC = 0x8b1f;

  /*
   * Trailer size in bytes.
   *
   */
  private final static int TRAILER_SIZE = 8;

    private OutputStream out;
    private byte[] buf;
    private CRC32 crc;
    private ZStream zip;
    private boolean closed;
    private boolean finished;


    public JGZipOutputStream(OutputStream out, byte[] buf) throws IOException{
        this.out = out;
        this.buf = buf;

        if (buf==null){
                throw new NullPointerException("buf");          
        }
        this.crc = new CRC32();     
        zip = new ZStream();
        initZStream(zip);


        writeHeader();
    }

    protected int initZStream(ZStream zip) {
        return zip.deflateInit(JZlib.Z_BEST_COMPRESSION-1, true);
    }

  /*
   * Writes GZIP member header.
   */

  private final static byte[] header = {
      (byte) GZIP_MAGIC,                // Magic number (short)
      (byte)(GZIP_MAGIC >> 8),          // Magic number (short)
      Deflater.DEFLATED,                // Compression method (CM)
      0,                                // Flags (FLG)
      0,                                // Modification time MTIME (int)
      0,                                // Modification time MTIME (int)
      0,                                // Modification time MTIME (int)
      0,                                // Modification time MTIME (int)
      0,                                // Extra flags (XFLG)
      0                                 // Operating system (OS)
  };

  private void writeHeader() throws IOException {
    out.write(header);
  }

  public void write(byte[] buf, int off, int len) throws IOException{
    if (off < 0 || len < 0 || off > buf.length - len) 
        throw new ArrayIndexOutOfBoundsException();
      if (finished)
        throw new EOFException();
    zip.next_in = buf;
    zip.next_in_index = off;
    zip.avail_in = len;

    deflate(JZlib.Z_NO_FLUSH);

    crc.update(buf, off, len);
  }

    private void deflate(int flushMode) throws IOException {
        final boolean force =  JZlib.Z_NO_FLUSH!=flushMode;
        while (zip.avail_in>0 || force){
        byte[] b = this.buf;
        int remaining;
        {
            zip.next_out_index = 0;
            remaining = b.length;           
        }                   

        zip.next_out = b;
        zip.avail_out =remaining;
        deflate(zip, this.finished?JZlib.Z_FINISH:flushMode);
        int len = remaining - zip.avail_out;

            out.write(this.buf, 0, len);

        if (force)
            return;
    }
    }

    private static void deflate(ZStream z, int flushMode) throws IOException {
        int err=z.deflate(flushMode); 
    if (err!=JZlib.Z_OK){
        boolean finish = JZlib.Z_FINISH==flushMode;
        if (finish && err == JZlib.Z_STREAM_END)
            return;

        throw new IOException(String.format("Deflate exception:[%s]  msg: %s", err, z.msg));
    }
    }

    public void flush() throws IOException {
        deflate(JZlib.Z_SYNC_FLUSH);
    }

    public void fullFlush() throws IOException {
        deflate(JZlib.Z_FULL_FLUSH);
    }

    public void finish() throws IOException {
        if (!finished) {
            finished = true;
            zip.avail_in=0;              

            do{
                deflate(JZlib.Z_FINISH);
            }while(zip.avail_out==0);               

            int err = zip.deflateEnd();     
            if (JZlib.Z_OK !=   err){
                throw new IOException(String.format("Deflate exception, finish error:[%s]  msg: %s", err, zip.msg));
            }

            writeTrailer(buf, 0);
            out.write(buf, 0 , TRAILER_SIZE);

        }
    }

  /*
   * Writes GZIP member trailer to a byte array, starting at a given
   * offset.
   */
  private void writeTrailer(byte[] buf, int offset) throws IOException {
      writeInt((int)crc.getValue(), buf, offset); // CRC-32 of uncompr. data
      writeInt((int)zip.total_in, buf, offset + 4); // Number of uncompr. bytes
  }

  /*
   * Writes integer in Intel byte order to a byte array, starting at a
   * given offset.
   */
  private void writeInt(int i, byte[] buf, int offset) throws IOException {
      writeShort(i & 0xffff, buf, offset);
      writeShort((i >> 16) & 0xffff, buf, offset + 2);
  }

  /*
   * Writes short integer in Intel byte order to a byte array, starting
   * at a given offset
   */
  private void writeShort(int s, byte[] buf, int offset) throws IOException {
      buf[offset] = (byte)(s & 0xff);
      buf[offset + 1] = (byte)((s >> 8) & 0xff);
  }

  public void close() throws IOException {
    if (!closed) {
        finish();
        out.close();
        closed = true;
    }
  }

  public void reset(){
    zip.free();
    initZStream(zip);
    crc.reset();
    this.finished = false;
    this.closed = false;
  }

    @Override
    public void write(int b) throws IOException {           
        write(new byte[]{(byte) b});
    }



    /**
     * Licensed to the Apache Software Foundation (ASF) under one
     * or more contributor license agreements.  See the NOTICE file
     * distributed with this work for additional information
     * regarding copyright ownership.  The ASF licenses this file
     * to you under the Apache License, Version 2.0 (the
     * "License"); you may not use this file except in compliance
     * with the License.  You may obtain a copy of the License at
     *
     *     http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */

    //from
    //https://issues.apache.org/jira/secure/attachment/12413610/PureJavaCrc32NewLoop.java



    /**
     * A pure-java implementation of the CRC32 checksum that uses
     * the same polynomial as the built-in native CRC32.
     *
     * This is to avoid the JNI overhead for certain uses of Checksumming
     * where many small pieces of data are checksummed in succession.
     *
     * The current version is ~10x to 1.8x as fast as Sun's native
     * java.util.zip.CRC32 in Java 1.6
     *
     * @see java.util.zip.CRC32
     */
    public static class CRC32 implements Checksum {

      /** the current CRC value, bit-flipped */
      int crc;

      /** {@inheritDoc} */
      public CRC32() {
        reset();
      }

      /** {@inheritDoc} */
      public long getValue() {
        return (~crc) & 0xffffffffL;
      }

      /** {@inheritDoc} */
      public void reset() {
        crc = ~0;
      }

      /** {@inheritDoc} */
      public void update(byte[] b, int off, final int len) {
        for(final int end = off + (len & ~3); off < end; ) {
          crc = T4[((crc) ^ b[off]) & 0xFF] 
                ^ T3[((crc >>> 8) ^ b[off+1]) & 0xFF] 
                ^ T2[((crc >>> 16) ^ b[off+2]) & 0xFF] 
                ^ T1[((crc >>> 24) ^ b[off+3]) & 0xFF];
          off +=4;
        }

        for(final int end = off + (len & 3); off < end; ) {
          crc = (crc >>> 8) ^ T1[(crc ^ b[off++]) & 0xff];
        }
      }

      /** {@inheritDoc} */
      final public void update(int b) {
        crc = (crc >>> 8) ^ T1[(crc ^ b) & 0xff];
      }

      /**
       * Pre-generated lookup tables. For the code to generate these tables
       * please see HDFS-297.
       */

      /** T1[x] is ~CRC(x) */
      private static final int[] T1 = new int[] {
        0x0, 0x77073096, 0xee0e612c, 0x990951ba,
        0x76dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
        0xedb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
        0x9b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
        0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
        0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
        0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
        0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
        0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
        0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
        0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
        0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
        0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
        0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
        0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
        0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
        0x76dc4190, 0x1db7106, 0x98d220bc, 0xefd5102a,
        0x71b18589, 0x6b6b51f, 0x9fbfe4a5, 0xe8b8d433,
        0x7807c9a2, 0xf00f934, 0x9609a88e, 0xe10e9818,
        0x7f6a0dbb, 0x86d3d2d, 0x91646c97, 0xe6635c01,
        0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
        0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
        0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
        0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
        0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
        0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
        0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
        0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
        0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
        0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
        0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
        0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
        0xedb88320, 0x9abfb3b6, 0x3b6e20c, 0x74b1d29a,
        0xead54739, 0x9dd277af, 0x4db2615, 0x73dc1683,
        0xe3630b12, 0x94643b84, 0xd6d6a3e, 0x7a6a5aa8,
        0xe40ecf0b, 0x9309ff9d, 0xa00ae27, 0x7d079eb1,
        0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
        0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
        0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
        0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
        0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
        0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
        0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
        0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
        0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
        0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
        0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
        0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
        0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x26d930a,
        0x9c0906a9, 0xeb0e363f, 0x72076785, 0x5005713,
        0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0xcb61b38,
        0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0xbdbdf21,
        0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
        0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
        0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
        0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
        0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
        0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
        0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
        0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
        0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
        0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
        0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
        0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
      };

      /** T2[x] is ~CRC(x followed by one 0x00 byte) */
      private static final int[] T2 = new int[] {
        0x0, 0x191b3141, 0x32366282, 0x2b2d53c3,
        0x646cc504, 0x7d77f445, 0x565aa786, 0x4f4196c7,
        0xc8d98a08, 0xd1c2bb49, 0xfaefe88a, 0xe3f4d9cb,
        0xacb54f0c, 0xb5ae7e4d, 0x9e832d8e, 0x87981ccf,
        0x4ac21251, 0x53d92310, 0x78f470d3, 0x61ef4192,
        0x2eaed755, 0x37b5e614, 0x1c98b5d7, 0x5838496,
        0x821b9859, 0x9b00a918, 0xb02dfadb, 0xa936cb9a,
        0xe6775d5d, 0xff6c6c1c, 0xd4413fdf, 0xcd5a0e9e,
        0x958424a2, 0x8c9f15e3, 0xa7b24620, 0xbea97761,
        0xf1e8e1a6, 0xe8f3d0e7, 0xc3de8324, 0xdac5b265,
        0x5d5daeaa, 0x44469feb, 0x6f6bcc28, 0x7670fd69,
        0x39316bae, 0x202a5aef, 0xb07092c, 0x121c386d,
        0xdf4636f3, 0xc65d07b2, 0xed705471, 0xf46b6530,
        0xbb2af3f7, 0xa231c2b6, 0x891c9175, 0x9007a034,
        0x179fbcfb, 0xe848dba, 0x25a9de79, 0x3cb2ef38,
        0x73f379ff, 0x6ae848be, 0x41c51b7d, 0x58de2a3c,
        0xf0794f05, 0xe9627e44, 0xc24f2d87, 0xdb541cc6,
        0x94158a01, 0x8d0ebb40, 0xa623e883, 0xbf38d9c2,
        0x38a0c50d, 0x21bbf44c, 0xa96a78f, 0x138d96ce,
        0x5ccc0009, 0x45d73148, 0x6efa628b, 0x77e153ca,
        0xbabb5d54, 0xa3a06c15, 0x888d3fd6, 0x91960e97,
        0xded79850, 0xc7cca911, 0xece1fad2, 0xf5facb93,
        0x7262d75c, 0x6b79e61d, 0x4054b5de, 0x594f849f,
        0x160e1258, 0xf152319, 0x243870da, 0x3d23419b,
        0x65fd6ba7, 0x7ce65ae6, 0x57cb0925, 0x4ed03864,
        0x191aea3, 0x188a9fe2, 0x33a7cc21, 0x2abcfd60,
        0xad24e1af, 0xb43fd0ee, 0x9f12832d, 0x8609b26c,
        0xc94824ab, 0xd05315ea, 0xfb7e4629, 0xe2657768,
        0x2f3f79f6, 0x362448b7, 0x1d091b74, 0x4122a35,
        0x4b53bcf2, 0x52488db3, 0x7965de70, 0x607eef31,
        0xe7e6f3fe, 0xfefdc2bf, 0xd5d0917c, 0xcccba03d,
        0x838a36fa, 0x9a9107bb, 0xb1bc5478, 0xa8a76539,
        0x3b83984b, 0x2298a90a, 0x9b5fac9, 0x10aecb88,
        0x5fef5d4f, 0x46f46c0e, 0x6dd93fcd, 0x74c20e8c,
        0xf35a1243, 0xea412302, 0xc16c70c1, 0xd8774180,
        0x9736d747, 0x8e2de606, 0xa500b5c5, 0xbc1b8484,
        0x71418a1a, 0x685abb5b, 0x4377e898, 0x5a6cd9d9,
        0x152d4f1e, 0xc367e5f, 0x271b2d9c, 0x3e001cdd,
        0xb9980012, 0xa0833153, 0x8bae6290, 0x92b553d1,
        0xddf4c516, 0xc4eff457, 0xefc2a794, 0xf6d996d5,
        0xae07bce9, 0xb71c8da8, 0x9c31de6b, 0x852aef2a,
        0xca6b79ed, 0xd37048ac, 0xf85d1b6f, 0xe1462a2e,
        0x66de36e1, 0x7fc507a0, 0x54e85463, 0x4df36522,
        0x2b2f3e5, 0x1ba9c2a4, 0x30849167, 0x299fa026,
        0xe4c5aeb8, 0xfdde9ff9, 0xd6f3cc3a, 0xcfe8fd7b,
        0x80a96bbc, 0x99b25afd, 0xb29f093e, 0xab84387f,
        0x2c1c24b0, 0x350715f1, 0x1e2a4632, 0x7317773,
        0x4870e1b4, 0x516bd0f5, 0x7a468336, 0x635db277,
        0xcbfad74e, 0xd2e1e60f, 0xf9ccb5cc, 0xe0d7848d,
        0xaf96124a, 0xb68d230b, 0x9da070c8, 0x84bb4189,
        0x3235d46, 0x1a386c07, 0x31153fc4, 0x280e0e85,
        0x674f9842, 0x7e54a903, 0x5579fac0, 0x4c62cb81,
        0x8138c51f, 0x9823f45e, 0xb30ea79d, 0xaa1596dc,
        0xe554001b, 0xfc4f315a, 0xd7626299, 0xce7953d8,
        0x49e14f17, 0x50fa7e56, 0x7bd72d95, 0x62cc1cd4,
        0x2d8d8a13, 0x3496bb52, 0x1fbbe891, 0x6a0d9d0,
        0x5e7ef3ec, 0x4765c2ad, 0x6c48916e, 0x7553a02f,
        0x3a1236e8, 0x230907a9, 0x824546a, 0x113f652b,
        0x96a779e4, 0x8fbc48a5, 0xa4911b66, 0xbd8a2a27,
        0xf2cbbce0, 0xebd08da1, 0xc0fdde62, 0xd9e6ef23,
        0x14bce1bd, 0xda7d0fc, 0x268a833f, 0x3f91b27e,
        0x70d024b9, 0x69cb15f8, 0x42e6463b, 0x5bfd777a,
        0xdc656bb5, 0xc57e5af4, 0xee530937, 0xf7483876,
        0xb809aeb1, 0xa1129ff0, 0x8a3fcc33, 0x9324fd72
      };

      /** T3[x] is ~CRC(x followed by two 0x00 bytes) */
      private static final int[] T3 = new int[] {
        0x0, 0x1c26a37, 0x384d46e, 0x246be59,
        0x709a8dc, 0x6cbc2eb, 0x48d7cb2, 0x54f1685,
        0xe1351b8, 0xfd13b8f, 0xd9785d6, 0xc55efe1,
        0x91af964, 0x8d89353, 0xa9e2d0a, 0xb5c473d,
        0x1c26a370, 0x1de4c947, 0x1fa2771e, 0x1e601d29,
        0x1b2f0bac, 0x1aed619b, 0x18abdfc2, 0x1969b5f5,
        0x1235f2c8, 0x13f798ff, 0x11b126a6, 0x10734c91,
        0x153c5a14, 0x14fe3023, 0x16b88e7a, 0x177ae44d,
        0x384d46e0, 0x398f2cd7, 0x3bc9928e, 0x3a0bf8b9,
        0x3f44ee3c, 0x3e86840b, 0x3cc03a52, 0x3d025065,
        0x365e1758, 0x379c7d6f, 0x35dac336, 0x3418a901,
        0x3157bf84, 0x3095d5b3, 0x32d36bea, 0x331101dd,
        0x246be590, 0x25a98fa7, 0x27ef31fe, 0x262d5bc9,
        0x23624d4c, 0x22a0277b, 0x20e69922, 0x2124f315,
        0x2a78b428, 0x2bbade1f, 0x29fc6046, 0x283e0a71,
        0x2d711cf4, 0x2cb376c3, 0x2ef5c89a, 0x2f37a2ad,
        0x709a8dc0, 0x7158e7f7, 0x731e59ae, 0x72dc3399,
        0x7793251c, 0x76514f2b, 0x7417f172, 0x75d59b45,
        0x7e89dc78, 0x7f4bb64f, 0x7d0d0816, 0x7ccf6221,
        0x798074a4, 0x78421e93, 0x7a04a0ca, 0x7bc6cafd,
        0x6cbc2eb0, 0x6d7e4487, 0x6f38fade, 0x6efa90e9,
        0x6bb5866c, 0x6a77ec5b, 0x68315202, 0x69f33835,
        0x62af7f08, 0x636d153f, 0x612bab66, 0x60e9c151,
        0x65a6d7d4, 0x6464bde3, 0x662203ba, 0x67e0698d,
        0x48d7cb20, 0x4915a117, 0x4b531f4e, 0x4a917579,
        0x4fde63fc, 0x4e1c09cb, 0x4c5ab792, 0x4d98dda5,
        0x46c49a98, 0x4706f0af, 0x45404ef6, 0x448224c1,
        0x41cd3244, 0x400f5873, 0x4249e62a, 0x438b8c1d,
        0x54f16850, 0x55330267, 0x5775bc3e, 0x56b7d609,
        0x53f8c08c, 0x523aaabb, 0x507c14e2, 0x51be7ed5,
        0x5ae239e8, 0x5b2053df, 0x5966ed86, 0x58a487b1,
        0x5deb9134, 0x5c29fb03, 0x5e6f455a, 0x5fad2f6d,
        0xe1351b80, 0xe0f771b7, 0xe2b1cfee, 0xe373a5d9,
        0xe63cb35c, 0xe7fed96b, 0xe5b86732, 0xe47a0d05,
        0xef264a38, 0xeee4200f, 0xeca29e56, 0xed60f461,
        0xe82fe2e4, 0xe9ed88d3, 0xebab368a, 0xea695cbd,
        0xfd13b8f0, 0xfcd1d2c7, 0xfe976c9e, 0xff5506a9,
        0xfa1a102c, 0xfbd87a1b, 0xf99ec442, 0xf85cae75,
        0xf300e948, 0xf2c2837f, 0xf0843d26, 0xf1465711,
        0xf4094194, 0xf5cb2ba3, 0xf78d95fa, 0xf64fffcd,
        0xd9785d60, 0xd8ba3757, 0xdafc890e, 0xdb3ee339,
        0xde71f5bc, 0xdfb39f8b, 0xddf521d2, 0xdc374be5,
        0xd76b0cd8, 0xd6a966ef, 0xd4efd8b6, 0xd52db281,
        0xd062a404, 0xd1a0ce33, 0xd3e6706a, 0xd2241a5d,
        0xc55efe10, 0xc49c9427, 0xc6da2a7e, 0xc7184049,
        0xc25756cc, 0xc3953cfb, 0xc1d382a2, 0xc011e895,
        0xcb4dafa8, 0xca8fc59f, 0xc8c97bc6, 0xc90b11f1,
        0xcc440774, 0xcd866d43, 0xcfc0d31a, 0xce02b92d,
        0x91af9640, 0x906dfc77, 0x922b422e, 0x93e92819,
        0x96a63e9c, 0x976454ab, 0x9522eaf2, 0x94e080c5,
        0x9fbcc7f8, 0x9e7eadcf, 0x9c381396, 0x9dfa79a1,
        0x98b56f24, 0x99770513, 0x9b31bb4a, 0x9af3d17d,
        0x8d893530, 0x8c4b5f07, 0x8e0de15e, 0x8fcf8b69,
        0x8a809dec, 0x8b42f7db, 0x89044982, 0x88c623b5,
        0x839a6488, 0x82580ebf, 0x801eb0e6, 0x81dcdad1,
        0x8493cc54, 0x8551a663, 0x8717183a, 0x86d5720d,
        0xa9e2d0a0, 0xa820ba97, 0xaa6604ce, 0xaba46ef9,
        0xaeeb787c, 0xaf29124b, 0xad6fac12, 0xacadc625,
        0xa7f18118, 0xa633eb2f, 0xa4755576, 0xa5b73f41,
        0xa0f829c4, 0xa13a43f3, 0xa37cfdaa, 0xa2be979d,
        0xb5c473d0, 0xb40619e7, 0xb640a7be, 0xb782cd89,
        0xb2cddb0c, 0xb30fb13b, 0xb1490f62, 0xb08b6555,
        0xbbd72268, 0xba15485f, 0xb853f606, 0xb9919c31,
        0xbcde8ab4, 0xbd1ce083, 0xbf5a5eda, 0xbe9834ed
      };

      /** T4[x] is ~CRC(x followed by three 0x00 bytes) */
      private static final int[] T4 = new int[] {
        0x0, 0xb8bc6765, 0xaa09c88b, 0x12b5afee,
        0x8f629757, 0x37def032, 0x256b5fdc, 0x9dd738b9,
        0xc5b428ef, 0x7d084f8a, 0x6fbde064, 0xd7018701,
        0x4ad6bfb8, 0xf26ad8dd, 0xe0df7733, 0x58631056,
        0x5019579f, 0xe8a530fa, 0xfa109f14, 0x42acf871,
        0xdf7bc0c8, 0x67c7a7ad, 0x75720843, 0xcdce6f26,
        0x95ad7f70, 0x2d111815, 0x3fa4b7fb, 0x8718d09e,
        0x1acfe827, 0xa2738f42, 0xb0c620ac, 0x87a47c9,
        0xa032af3e, 0x188ec85b, 0xa3b67b5, 0xb28700d0,
        0x2f503869, 0x97ec5f0c, 0x8559f0e2, 0x3de59787,
        0x658687d1, 0xdd3ae0b4, 0xcf8f4f5a, 0x7733283f,
        0xeae41086, 0x525877e3, 0x40edd80d, 0xf851bf68,
        0xf02bf8a1, 0x48979fc4, 0x5a22302a, 0xe29e574f,
        0x7f496ff6, 0xc7f50893, 0xd540a77d, 0x6dfcc018,
        0x359fd04e, 0x8d23b72b, 0x9f9618c5, 0x272a7fa0,
        0xbafd4719, 0x241207c, 0x10f48f92, 0xa848e8f7,
        0x9b14583d, 0x23a83f58, 0x311d90b6, 0x89a1f7d3,
        0x1476cf6a, 0xaccaa80f, 0xbe7f07e1, 0x6c36084,
        0x5ea070d2, 0xe61c17b7, 0xf4a9b859, 0x4c15df3c,
        0xd1c2e785, 0x697e80e0, 0x7bcb2f0e, 0xc377486b,
        0xcb0d0fa2, 0x73b168c7, 0x6104c729, 0xd9b8a04c,
        0x446f98f5, 0xfcd3ff90, 0xee66507e, 0x56da371b,
        0xeb9274d, 0xb6054028, 0xa4b0efc6, 0x1c0c88a3,
        0x81dbb01a, 0x3967d77f, 0x2bd27891, 0x936e1ff4,
        0x3b26f703, 0x839a9066, 0x912f3f88, 0x299358ed,
        0xb4446054, 0xcf80731, 0x1e4da8df, 0xa6f1cfba,
        0xfe92dfec, 0x462eb889, 0x549b1767, 0xec277002,
        0x71f048bb, 0xc94c2fde, 0xdbf98030, 0x6345e755,
        0x6b3fa09c, 0xd383c7f9, 0xc1366817, 0x798a0f72,
        0xe45d37cb, 0x5ce150ae, 0x4e54ff40, 0xf6e89825,
        0xae8b8873, 0x1637ef16, 0x48240f8, 0xbc3e279d,
        0x21e91f24, 0x99557841, 0x8be0d7af, 0x335cb0ca,
        0xed59b63b, 0x55e5d15e, 0x47507eb0, 0xffec19d5,
        0x623b216c, 0xda874609, 0xc832e9e7, 0x708e8e82,
        0x28ed9ed4, 0x9051f9b1, 0x82e4565f, 0x3a58313a,
        0xa78f0983, 0x1f336ee6, 0xd86c108, 0xb53aa66d,
        0xbd40e1a4, 0x5fc86c1, 0x1749292f, 0xaff54e4a,
        0x322276f3, 0x8a9e1196, 0x982bbe78, 0x2097d91d,
        0x78f4c94b, 0xc048ae2e, 0xd2fd01c0, 0x6a4166a5,
        0xf7965e1c, 0x4f2a3979, 0x5d9f9697, 0xe523f1f2,
        0x4d6b1905, 0xf5d77e60, 0xe762d18e, 0x5fdeb6eb,
        0xc2098e52, 0x7ab5e937, 0x680046d9, 0xd0bc21bc,
        0x88df31ea, 0x3063568f, 0x22d6f961, 0x9a6a9e04,
        0x7bda6bd, 0xbf01c1d8, 0xadb46e36, 0x15080953,
        0x1d724e9a, 0xa5ce29ff, 0xb77b8611, 0xfc7e174,
        0x9210d9cd, 0x2aacbea8, 0x38191146, 0x80a57623,
        0xd8c66675, 0x607a0110, 0x72cfaefe, 0xca73c99b,
        0x57a4f122, 0xef189647, 0xfdad39a9, 0x45115ecc,
        0x764dee06, 0xcef18963, 0xdc44268d, 0x64f841e8,
        0xf92f7951, 0x41931e34, 0x5326b1da, 0xeb9ad6bf,
        0xb3f9c6e9, 0xb45a18c, 0x19f00e62, 0xa14c6907,
        0x3c9b51be, 0x842736db, 0x96929935, 0x2e2efe50,
        0x2654b999, 0x9ee8defc, 0x8c5d7112, 0x34e11677,
        0xa9362ece, 0x118a49ab, 0x33fe645, 0xbb838120,
        0xe3e09176, 0x5b5cf613, 0x49e959fd, 0xf1553e98,
        0x6c820621, 0xd43e6144, 0xc68bceaa, 0x7e37a9cf,
        0xd67f4138, 0x6ec3265d, 0x7c7689b3, 0xc4caeed6,
        0x591dd66f, 0xe1a1b10a, 0xf3141ee4, 0x4ba87981,
        0x13cb69d7, 0xab770eb2, 0xb9c2a15c, 0x17ec639,
        0x9ca9fe80, 0x241599e5, 0x36a0360b, 0x8e1c516e,
        0x866616a7, 0x3eda71c2, 0x2c6fde2c, 0x94d3b949,
        0x90481f0, 0xb1b8e695, 0xa30d497b, 0x1bb12e1e,
        0x43d23e48, 0xfb6e592d, 0xe9dbf6c3, 0x516791a6,
        0xccb0a91f, 0x740cce7a, 0x66b96194, 0xde0506f1
      };


    }

}

Answer 3

JZlib 不支持 Gzip 数据格式 (RFC 1952)，仅 zlib (RFC 1950) 和普通 deflate (RFC 1951 ）。

这些格式仅因标头和末尾的校验和：

• gzip 是deflate，标头包含文件元信息，末尾有 CRC32 校验和，
• zlib em> 是 deflate，带有一个微小的压缩方法标头和末尾的 Adler32 校验和。

因此，您可以围绕 jzlib 的 deflate 压缩流编写自己的包装器（使用 nowrap=true 以避免 zlib 标头），添加元数据和 CRC32 校验和。或者你看看其他人是否已经这样做了。 （看起来 bestsss 的回答就是关于这个的。）