在很多的時(shí)候，需要將重要信息加密，而以下類(lèi)就是在java中如何加密和解密經(jīng)常用到的代碼：
1
package cn.com.hkgt.apps.util;
2
3
4import java.security.*;
5import javax.crypto.Cipher;
6import javax.crypto.SecretKey;
7import javax.crypto.SecretKeyFactory;
8import javax.crypto.spec.DESKeySpec;
9
10
/** *//**
11
* 字符串工具集合
12
*/
13public class StringUtils 
{
14
15 private static final String PASSWORD_CRYPT_KEY = "cindaportal";
16private final static String DES = "DES";
17
18
/** *//**
19 * 加密
20 * @param src 數(shù)據(jù)源
21 * @param key 密鑰，長(zhǎng)度必須是8的倍數(shù)
22 * @return 返回加密后的數(shù)據(jù)
23 * @throws Exception
24
*/
25public static byte[] encrypt(byte[] src, byte[] key)throws Exception {
26 //DES算法要求有一個(gè)可信任的隨機(jī)數(shù)源
27 SecureRandom sr = new SecureRandom();
28 // 從原始密匙數(shù)據(jù)創(chuàng)建DESKeySpec對(duì)象
29 DESKeySpec dks = new DESKeySpec(key);
30 // 創(chuàng)建一個(gè)密匙工廠，然后用它把DESKeySpec轉(zhuǎn)換成
31 // 一個(gè)SecretKey對(duì)象
32 SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
33 SecretKey securekey = keyFactory.generateSecret(dks);
34 // Cipher對(duì)象實(shí)際完成加密操作
35 Cipher cipher = Cipher.getInstance(DES);
36 // 用密匙初始化Cipher對(duì)象
37 cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);
38 // 現(xiàn)在，獲取數(shù)據(jù)并加密
39 // 正式執(zhí)行加密操作
40 return cipher.doFinal(src);
41 }
42
43 /** *//**
44 * 解密
45 * @param src 數(shù)據(jù)源
46 * @param key 密鑰，長(zhǎng)度必須是8的倍數(shù)
47 * @return 返回解密后的原始數(shù)據(jù)
48 * @throws Exception
49 */
50 public static byte[] decrypt(byte[] src, byte[] key)throws Exception {
51 // DES算法要求有一個(gè)可信任的隨機(jī)數(shù)源
52 SecureRandom sr = new SecureRandom();
53 // 從原始密匙數(shù)據(jù)創(chuàng)建一個(gè)DESKeySpec對(duì)象
54 DESKeySpec dks = new DESKeySpec(key);
55 // 創(chuàng)建一個(gè)密匙工廠，然后用它把DESKeySpec對(duì)象轉(zhuǎn)換成
56 // 一個(gè)SecretKey對(duì)象
57 SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
58 SecretKey securekey = keyFactory.generateSecret(dks);
59 // Cipher對(duì)象實(shí)際完成解密操作
60 Cipher cipher = Cipher.getInstance(DES);
61 // 用密匙初始化Cipher對(duì)象
62 cipher.init(Cipher.DECRYPT_MODE, securekey, sr);
63 // 現(xiàn)在，獲取數(shù)據(jù)并解密
64 // 正式執(zhí)行解密操作
65 return cipher.doFinal(src);
66 }
67 /** *//**
68 * 密碼解密
69 * @param data
70 * @return
71 * @throws Exception
72 */
73 public final static String decrypt(String data){
74 try {
75 return new String(decrypt(hex2byte(data.getBytes()),PASSWORD_CRYPT_KEY.getBytes()));
76 }catch(Exception e) {
77 }
78 return null;
79 }
80 /** *//**
81 * 密碼加密
82 * @param password
83 * @return
84 * @throws Exception
85 */
86 public final static String encrypt(String password){
87 try {
88 return byte2hex(encrypt(password.getBytes(),PASSWORD_CRYPT_KEY.getBytes()));
89 }catch(Exception e) {
90 }
91 return null;
92 }
93/** *//**
94 * 二行制轉(zhuǎn)字符串
95 * @param b
96 * @return
97 */
98 public static String byte2hex(byte[] b) {
99 String hs = "";
100 String stmp = "";
101 for (int n = 0; n < b.length; n++) {
102 stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));
103 if (stmp.length() == 1)
104 hs = hs + "0" + stmp;
105 else
106 hs = hs + stmp;
107 }
108 return hs.toUpperCase();
109 }
110
111 public static byte[] hex2byte(byte[] b) {
112 if((b.length%2)!=0)
113 throw new IllegalArgumentException("長(zhǎng)度不是偶數(shù)");
114 byte[] b2 = new byte[b.length/2];
115 for (int n = 0; n < b.length; n+=2) {
116 String item = new String(b,n,2);
117 b2[n/2] = (byte)Integer.parseInt(item,16);
118 }
119 return b2;
120 }
121
122 public static void main(String[] args) {
123 String pwd = "測(cè)試dasdfaaaaaaa";
124 System.out.println("測(cè)試數(shù)據(jù)="+pwd);
125 String data = encrypt(pwd);
126 System.out.println("加密后的數(shù)據(jù)data="+data);
127 pwd = decrypt(data);
128 System.out.println("解密后="+pwd);
129
130 }
131}
132
133
134
posted on 2007-06-26 14:33
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