Java中实现DES加解密的一个类

//转byte应该要指定编码方式（不然可能会出错）//PASSWORD_CRYPT_KEY需要为八位字节 package com.global.util;import java.io.UnsupportedEncodingException;import java.security.*;import javax.crypto.Cipher;import javax.crypto.SecretKey;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.DESKeySpec;import junit.framework.TestCase;public class CodeUtil extends TestCase{private static final String PASSWORD_CRYPT_KEY = "_kong____";private final static String DES = "DES";/** * 加密 * @param src 数据源 * @param key 密钥，长度必须是8的倍数 * @return  返回加密后的数据 * @throws Exception */public static byte[] encrypt(byte[] src, byte[] key)throws Exception {//DES算法要求有一个可信任的随机数源SecureRandom sr = new SecureRandom();// 从原始密匙数据创建DESKeySpec对象DESKeySpec dks = new DESKeySpec(key);// 创建一个密匙工厂，然后用它把DESKeySpec转换成// 一个SecretKey对象SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);SecretKey securekey = keyFactory.generateSecret(dks);// Cipher对象实际完成加密操作Cipher cipher = Cipher.getInstance(DES);// 用密匙初始化Cipher对象cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);// 现在，获取数据并加密// 正式执行加密操作return cipher.doFinal(src);}/** * 解密 * @param src 数据源 * @param key 密钥，长度必须是8的倍数 * @return   返回解密后的原始数据 * @throws Exception */public static byte[] decrypt(byte[] src, byte[] key)throws Exception {// DES算法要求有一个可信任的随机数源SecureRandom sr = new SecureRandom();// 从原始密匙数据创建一个DESKeySpec对象DESKeySpec dks = new DESKeySpec(key);// 创建一个密匙工厂，然后用它把DESKeySpec对象转换成// 一个SecretKey对象SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);SecretKey securekey = keyFactory.generateSecret(dks);// Cipher对象实际完成解密操作Cipher cipher = Cipher.getInstance(DES);// 用密匙初始化Cipher对象cipher.init(Cipher.DECRYPT_MODE, securekey, sr);// 现在，获取数据并解密// 正式执行解密操作return cipher.doFinal(src);}/** * 密码解密 * @param data * @return * @throws Exception */public final static String decoder(String data){try {return new String(decrypt(hex2byte(data.getBytes("ISO-8859-1")),PASSWORD_CRYPT_KEY.getBytes("ISO-8859-1")));}catch(Exception e) {}return null;}/** * 密码加密 * @param password * @return * @throws Exception */public final static String encoder(String password){try {return byte2hex(encrypt(password.getBytes("ISO-8859-1"),PASSWORD_CRYPT_KEY.getBytes("ISO-8859-1")));}catch(Exception e) {}return null;}/** * 二行制转字符串 * @param b * @return */public static String byte2hex(byte[] b) {String hs = "";String stmp = "";for (int n = 0; n < b.length; n++) {stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));if (stmp.length() == 1)hs = hs + "0" + stmp;elsehs = hs + stmp;}return hs.toUpperCase();}public static byte[] hex2byte(byte[] b) {if((b.length%2)!=0)throw new IllegalArgumentException("长度不是偶数");byte[] b2 = new byte[b.length/2];for (int n = 0; n < b.length; n+=2) {String item = new String(b,n,2);b2[n/2] = (byte)Integer.parseInt(item,16);}return b2;}public void test() throws UnsupportedEncodingException{String a = "zhazha";String b = byte2hex(a.getBytes("ISO-8859-1"));//String c = encrypt(b);System.out.println(decoder(encoder(a)));}}