GZIP压缩与解压缩

 GZIP压缩/解压

package com.hnkc.core.util;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;


public class GzipUtils {
        //压缩
	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;
	}
        //解压
	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;
	}

}

工具代码集合 

package com.hnkc.core.util;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

public class GZIPUtilsx  {
    public static final String GZIP_ENCODE_UTF_8 = "UTF-8"; 
    public static final String GZIP_ENCODE_ISO_8859_1 = "ISO-8859-1";

    
    public static byte[] compress(String str, String encoding) {
        if (str == null || str.length() == 0) {
            return null;
        }
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        GZIPOutputStream gzip;
        try {
            gzip = new GZIPOutputStream(out);
            gzip.write(str.getBytes(encoding));
            gzip.close();
        } catch ( Exception e) {
            e.printStackTrace();
        }
        return out.toByteArray();
    }
    
    public static byte[] compress(String str) throws IOException {  
        return compress(str, GZIP_ENCODE_UTF_8);  
    }
    
    public static byte[] uncompress(byte[] bytes) {
        if (bytes == null || bytes.length == 0) {
            return null;
        }
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        ByteArrayInputStream in = new ByteArrayInputStream(bytes);
        try {
            GZIPInputStream ungzip = new GZIPInputStream(in);
            byte[] buffer = new byte[256];
            int n;
            while ((n = ungzip.read(buffer)) >= 0) {
                out.write(buffer, 0, n);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return out.toByteArray();
    }
    
    public static String uncompressToString(byte[] bytes, String encoding) {  
        if (bytes == null || bytes.length == 0) {  
            return null;  
        }  
        ByteArrayOutputStream out = new ByteArrayOutputStream();  
        ByteArrayInputStream in = new ByteArrayInputStream(bytes);  
        try {
            GZIPInputStream ungzip = new GZIPInputStream(in);  
            byte[] buffer = new byte[256];  
            int n;  
            while ((n = ungzip.read(buffer)) >= 0) {  
                out.write(buffer, 0, n);  
            }  
            return out.toString(encoding);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
    
    public static String uncompressToString(byte[] bytes) {  
        return uncompressToString(bytes, GZIP_ENCODE_UTF_8);  
    } 
    
    public static void main(String[] args) throws IOException {
        String s = "method=login&userid=admin&userpwd=admin";
        System.out.println("字符串长度："+s.length());
        System.out.println("压缩后：："+compress(s).length);
        String ss = new String(compress(s));
        System.out.println(ss);
        
        System.out.println("解压后："+uncompress(compress(s)).length);
        System.out.println("解压字符串后：："+uncompressToString(compress(s)).length());
    }
}