java使用gzip实现文件解压缩示例

package com.cjonline.foundation.cpe.action;

import java.io.bytearrayinputstream;
import java.io.bytearrayoutputstream;
import java.io.file;
import java.io.fileinputstream;
import java.io.fileoutputstream;
import java.io.inputstream;
import java.io.outputstream;
import java.util.zip.gzipinputstream;
import java.util.zip.gzipoutputstream;

public abstract class gziputils { 

    public static final int buffer = 1024; 
    public static final string ext = ".gz"; 

    /**
     * 数据压缩
     * 
     * @param data
     * @return
     * @throws exception
     */ 
    public static byte[] compress(byte[] data) throws exception { 
        bytearrayinputstream bais = new bytearrayinputstream(data); 
        bytearrayoutputstream baos = new bytearrayoutputstream(); 

        // 压缩 
        compress(bais, baos); 

        byte[] output = baos.tobytearray(); 

        baos.flush(); 
        baos.close(); 

        bais.close(); 

        return output; 
    } 

    /**
     * 文件压缩
     * 
     * @param file
     * @throws exception
     */ 
    public static void compress(file file) throws exception { 
        compress(file, true); 
    } 

    /**
     * 文件压缩
     * 
     * @param file
     * @param delete
     *            是否删除原始文件
     * @throws exception
     */ 
    public static void compress(file file, boolean delete) throws exception { 
        fileinputstream fis = new fileinputstream(file); 
        fileoutputstream fos = new fileoutputstream(file.getpath() + ext); 

        compress(fis, fos); 

        fis.close(); 
        fos.flush(); 
        fos.close(); 

        if (delete) { 
            file.delete(); 
        } 
    } 

    /**
     * 数据压缩
     * 
     * @param is
     * @param os
     * @throws exception
     */ 
    public static void compress(inputstream is, outputstream os) 
            throws exception { 

        gzipoutputstream gos = new gzipoutputstream(os); 

        int count; 
        byte data[] = new byte[buffer]; 
        while ((count = is.read(data, 0, buffer)) != -1) { 
            gos.write(data, 0, count); 
        } 

        gos.finish(); 

        gos.flush(); 
        gos.close(); 
    } 

    /**
     * 文件压缩
     * 
     * @param path
     * @throws exception
     */ 
    public static void compress(string path) throws exception { 
        compress(path, true); 
    } 

    /**
     * 文件压缩
     * 
     * @param path
     * @param delete
     *            是否删除原始文件
     * @throws exception
     */ 
    public static void compress(string path, boolean delete) throws exception { 
        file file = new file(path); 
        compress(file, delete); 
    } 

    /**
     * 数据解压缩
     * 
     * @param data
     * @return
     * @throws exception
     */ 
    public static byte[] decompress(byte[] data) throws exception { 
        bytearrayinputstream bais = new bytearrayinputstream(data); 
        bytearrayoutputstream baos = new bytearrayoutputstream(); 

        // 解压缩 

        decompress(bais, baos); 

        data = baos.tobytearray(); 

        baos.flush(); 
        baos.close(); 

        bais.close(); 

        return data; 
    } 

    /**
     * 文件解压缩
     * 
     * @param file
     * @throws exception
     */ 
    public static void decompress(file file) throws exception { 
        decompress(file, true); 
    } 

    /**
     * 文件解压缩
     * 
     * @param file
     * @param delete
     *            是否删除原始文件
     * @throws exception
     */ 
    public static void decompress(file file, boolean delete) throws exception { 
        fileinputstream fis = new fileinputstream(file); 
        fileoutputstream fos = new fileoutputstream(file.getpath().replace(ext, 
                "")); 
        decompress(fis, fos); 
        fis.close(); 
        fos.flush(); 
        fos.close(); 

        if (delete) { 
            file.delete(); 
        } 
    } 

    /**
     * 数据解压缩
     * 
     * @param is
     * @param os
     * @throws exception
     */ 
    public static void decompress(inputstream is, outputstream os) 
            throws exception { 

        gzipinputstream gis = new gzipinputstream(is); 

        int count; 
        byte data[] = new byte[buffer]; 
        while ((count = gis.read(data, 0, buffer)) != -1) { 
            os.write(data, 0, count); 
        } 

        gis.close(); 
    } 

    /**
     * 文件解压缩
     * 
     * @param path
     * @throws exception
     */ 
    public static void decompress(string path) throws exception { 
        decompress(path, true); 
    } 

    /**
     * 文件解压缩
     * 
     * @param path
     * @param delete
     *            是否删除原始文件
     * @throws exception
     */ 
    public static void decompress(string path, boolean delete) throws exception { 
        file file = new file(path); 
        decompress(file, delete); 
    } 
}