在解压gz文件时，如果直接用java.util.zip.GZIPInputStream来处理问题只能解压很少一部分内容，通过类MultiMemberGZIPInputStream 可以完全解压一个gz文件。

在解压gz文件时，如果直接用java.util.zip.GZIPInputStream来处理问题只能解压很少一部分内容，通过类MultiMemberGZIPInputStream 可以完全解压一个gz文件。

import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream;
import java.util.zip.GZIPInputStream;

public class MultiMemberGZIPInputStream extends GZIPInputStream {

public MultiMemberGZIPInputStream(InputStream in, int size)
    throws IOException {
   // Wrap the stream in a PushbackInputStream...
   super(new PushbackInputStream(in, size), size);
   this.size = size;
}

public MultiMemberGZIPInputStream(InputStream in) throws IOException {
   // Wrap the stream in a PushbackInputStream...
   super(new PushbackInputStream(in, 1024));
   this.size = -1;
}

private MultiMemberGZIPInputStream(MultiMemberGZIPInputStream parent)
    throws IOException {
   super(parent.in);
   this.size = -1;
   this.parent = parent.parent == null ? parent : parent.parent;
   this.parent.child = this;
}

private MultiMemberGZIPInputStream(MultiMemberGZIPInputStream parent,
    int size) throws IOException {
   super(parent.in, size);
   this.size = size;
   this.parent = parent.parent == null ? parent : parent.parent;
   this.parent.child = this;
}

private MultiMemberGZIPInputStream parent;

private MultiMemberGZIPInputStream child;

private int size;

private boolean eos;

public int read(byte[] inputBuffer, int inputBufferOffset,
    int inputBufferLen) throws IOException {

   if (eos) {
    return -1;
   }
   if (this.child != null)
    return this.child.read(inputBuffer, inputBufferOffset,
      inputBufferLen);

   int charsRead = super.read(inputBuffer, inputBufferOffset,
     inputBufferLen);
   if (charsRead == -1) {
    // Push any remaining buffered data back onto the stream
    // If the stream is then not empty, use it to construct
    // a new instance of this class and delegate this and any
    // future calls to it...
    int n = inf.getRemaining() - 8;
    if (n > 0) {
     // More than 8 bytes remaining in deflater
     // First 8 are gzip trailer. Add the rest to
     // any un-read data...
     ((PushbackInputStream) this.in).unread(buf, len - n, n);
    } else {
     // Nothing in the buffer. We need to know whether or not
     // there is unread data available in the underlying stream
     // since the base class will not handle an empty file.
     // Read a byte to see if there is data and if so,
     // push it back onto the stream...
     byte[] b = new byte[1];
     int ret = in.read(b, 0, 1);
     if (ret == -1) {
      eos = true;
      return -1;
     } else
      ((PushbackInputStream) this.in).unread(b, 0, 1);
    }

    MultiMemberGZIPInputStream child;
    if (this.size == -1)
     child = new MultiMemberGZIPInputStream(this);
    else
     child = new MultiMemberGZIPInputStream(this, this.size);
    return child.read(inputBuffer, inputBufferOffset, inputBufferLen);
   } else
    return charsRead;
}

}

 

 

应用示例：

try {
    int nnumber;

    FileInputStream fin = new FileInputStream(gzPath);

    MultiMemberGZIPInputStream MmGz = new MultiMemberGZIPInputStream(fin);
    FileOutputStream fout = new FileOutputStream(topath);

    byte[] buf = new byte[1024];

    nnumber = MmGz.read(buf, 0, buf.length);

    while (nnumber != -1) {

         fout.write(buf, 0, nnumber);
         nnumber = MmGz.read(buf, 0, buf.length);

}
    MmGz.close();
    fout.close();
    fin.close();

   } catch (Exception e) {
    e.printStackTrace();
   }