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();
}