图片解压缩

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

/** * User : Jixiaohu * Date : 2017-07-03. * Time : 16:18. */public class GzipUtils {

public static byte[] gzip(byte[] data) throws Exception {        ByteArrayOutputStream bos = new ByteArrayOutputStream();        GZIPOutputStream gzip = new GZIPOutputStream(bos);        gzip.write(data);        gzip.finish();        gzip.close();        byte[] ret = bos.toByteArray();        bos.close();        return ret;    }

public static byte[] ungzip(byte[] data) throws Exception {        ByteArrayInputStream bis = new ByteArrayInputStream(data);        GZIPInputStream gzip = new GZIPInputStream(bis);        byte[] buf = new byte[1024];        int num = -1;        ByteArrayOutputStream bos = new ByteArrayOutputStream();        while ((num = gzip.read(buf, 0, buf.length)) != -1) {            bos.write(buf, 0, num);        }        gzip.close();        bis.close();        byte[] ret = bos.toByteArray();        bos.flush();        bos.close();        return ret;    }

public static void main(String[] args) throws Exception {        //读取文件        String readPath = System.getProperty("user.dir") + File.separator                + "sources" + File.separatorChar + "006.jpg";        System.out.println(readPath);        File file = new File(readPath);        FileInputStream in = new FileInputStream(file);        byte[] data = new byte[in.available()];        in.read(data);        in.close();

System.out.println("文件原始大小：" + data.length);

//测试压缩        byte[] ret1 = GzipUtils.gzip(data);        System.out.println("压缩之后大小：" + ret1.length);

//测试解压缩        byte[] ret2 = GzipUtils.ungzip(ret1);        System.out.println("还原之后大小：" + ret2.length);

//写出文件        String writePath = System.getProperty("user.dir") + File.separatorChar                +"receive" + File.separatorChar+"006.jpg";        System.out.println(writePath);        FileOutputStream fos = new FileOutputStream(writePath);        fos.write(ret2);        fos.close();    }}