GZIPUtil 

  1 package com.jf.utils;  
  2   
  3 import java.io.ByteArrayInputStream;  
  4 import java.io.ByteArrayOutputStream;  
  5 import java.io.IOException;  
  6 import java.util.zip.GZIPInputStream;  
  7 import java.util.zip.GZIPOutputStream;  
  8   
  9   
 10   
 11 /** 
 12  *  GZIPUtils工具类
 13  */  
 14 public class GZIPUtils {  
 15   
 16     private static final String GZIP_ENCODE_UTF_8 = "UTF-8";  
 17   
 18     @SuppressWarnings("unused")
 19     private static final String GZIP_ENCODE_ISO_8859_1 = "ISO-8859-1";  
 20   
 21     /** 
 22      * 字符串压缩为GZIP字节数组 
 23      * @param str 
 24      * @return 
 25      */  
 26     public static byte[] compress(String str) {  
 27         return compress(str, GZIP_ENCODE_UTF_8);  
 28     }  
 29   
 30     /** 
 31      * 字符串压缩为GZIP字节数组 
 32      * @param str 
 33      * @param encoding 
 34      * @return 
 35      */  
 36     public static byte[] compress(String str, String encoding) {  
 37         if (str == null || str.length() == 0)  
 38             return null;  
 39         ByteArrayOutputStream out = new ByteArrayOutputStream();  
 40         GZIPOutputStream gzip;  
 41         try {  
 42             gzip = new GZIPOutputStream(out);  
 43             gzip.write(str.getBytes(encoding));  
 44             gzip.close();  
 45         } catch (IOException e) { 
 46         return null;
 47         }  
 48         return out.toByteArray();  
 49     }  
 50   
 51     /** 
 52      * GZIP解压缩 
 53      * @param bytes 
 54      * @return 
 55      */  
 56     public static byte[] uncompress(byte[] bytes) {  
 57         if (bytes == null || bytes.length == 0)   
 58             return null;  
 59         ByteArrayOutputStream out = new ByteArrayOutputStream();  
 60         ByteArrayInputStream in = new ByteArrayInputStream(bytes);  
 61         try {  
 62             GZIPInputStream ungzip = new GZIPInputStream(in);  
 63             byte[] buffer = new byte[256];  
 64             int n;  
 65             while ((n = ungzip.read(buffer)) >= 0) {  
 66                 out.write(buffer, 0, n);  
 67             }  
 68         } catch (IOException e) {  
 69         return null;
 70         }  
 71         return out.toByteArray();  
 72     }  
 73   
 74     /** 
 75      * @param bytes 
 76      * @return 
 77      */  
 78     public static String uncompressToString(byte[] bytes) {  
 79         return uncompressToString(bytes, GZIP_ENCODE_UTF_8);  
 80     }  
 81   
 82     /** 
 83      *  
 84      * @param bytes 
 85      * @param encoding 
 86      * @return 
 87      */  
 88     public static String uncompressToString(byte[] bytes, String encoding) {  
 89         if (bytes == null || bytes.length == 0)  
 90             return null;  
 91         ByteArrayOutputStream out = new ByteArrayOutputStream();  
 92         ByteArrayInputStream in = new ByteArrayInputStream(bytes);  
 93         try {  
 94             GZIPInputStream ungzip = new GZIPInputStream(in);  
 95             byte[] buffer = new byte[256];  
 96             int n;  
 97             while ((n = ungzip.read(buffer)) >= 0) {  
 98                 out.write(buffer, 0, n);  
 99             }  
100             return out.toString(encoding);  
101         } catch (IOException e) {
102         return null;  
103         }  
104     }  
105   
106     public static void main(String[] args) {  
107         String str = "xxxx";  
108         System.out.println("原长度:" + str.length());  
109         System.out.println("压缩后字符串长度:" + GZIPUtils.compress(str).toString().length());  
110         System.out.println("压缩后字符串:" + GZIPUtils.compress(str).toString());  
111 //        System.out.println("解压缩后字符串:" + StringUtils.newStringUtf8(GZIPUtils.uncompress(GZIPUtils.compress(str))));  
112         System.out.println("解压缩后字符串:" + GZIPUtils.uncompressToString(GZIPUtils.compress(str)));  
113     }  
114 }

 

posted @ 2018-09-16 22:32  面向bug编程  阅读(691)  评论(0)    收藏  举报