描述:利用Gzip进行文件压缩

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package com.util;

import java.io.*;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

public class GZipUtils {

public static final int BUFFER = 1024;
public static final String EXT = ".gz";

public static void main(String[] args) throws Exception {
String userHome = System.getProperties().getProperty("user.home"); // 用户目录,如:C:\Users\chushiyun
String fileName = userHome+"/01.jpg"; // 用户目录下的01.jpg 会被压缩成01.jpg.gz
compress(new File(fileName));
}
/**
* 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);
}
}