java的常用 MD5 DES加密代码【转】
import java.io.UnsupportedEncodingException; import java.security.MessageDigest; import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; /** * 一般加密解密工具<br> * DESede/DES/BlowFish<br> * DES的密钥(key)长度是为8个字节,加密解密的速度是最快的<br> * DESede的密钥(key)长度是24个字节<br> * BlowFish的密钥(key)是可变的 加密最快，强度最高,密钥长度范围(1<=key<=16)<br> * * @author songdawei * @version 1.0 * @date 2008-10-20 */ public class SecretCodeUtil { public final static String DES = "DES"; public final static String DESEDE = "DESede"; public final static String BLOWFISH = "BlowFish"; public final static String MD5 = "MD5"; /** * md5加密 * * @param plainText * @return */ public static String getMD5ofStr(String plainText) { try { return getMD5ofStr(string2Bytes(plainText)); } catch (Exception e) { e.printStackTrace(); } return null; } public static String getMD5ofStr(byte str[]) { try { MessageDigest md = MessageDigest.getInstance(MD5); md.update(str); byte b[] = md.digest(); return bytes2HexString(b); } catch (Exception e) { e.printStackTrace(); } return null; } /** * 对数据源进行加密 * * @param src * 数据源 * @param key * 密钥 * @param name * 算法的名称 * @return 返回加密后的数据 * @throws Exception */ public static byte[] encrypt(byte[] src, byte[] key, String name) throws Exception { SecretKeySpec securekey = new SecretKeySpec(key, name); // Cipher对象实际完成加密操作 Cipher cipher = Cipher.getInstance(name); // 用密匙初始化Cipher对象 cipher.init(Cipher.ENCRYPT_MODE, securekey); // 现在，获取数据并加密 // 正式执行加密操作 return cipher.doFinal(src); } /** * 对加密的数据源进行解密 * * @param src * 数据源 * @param key * 密钥 * @param name * 算法的名称 * @return 返回解密后的原始数据 * @throws Exception */ public static byte[] decrypt(byte[] src, byte[] key, String name) throws Exception { SecretKeySpec securekey = new SecretKeySpec(key, name); // Cipher对象实际完成解密操作 Cipher cipher = Cipher.getInstance(name); // 用密匙初始化Cipher对象 cipher.init(Cipher.DECRYPT_MODE, securekey); // 现在，获取数据并解密 // 正式执行解密操作 return cipher.doFinal(src); } /** * 二行制转字符串 * * @param b * @return */ public static String bytes2HexString(byte[] bytes) { String hs = null; if (bytes != null) { final int size = bytes.length; if (size > 0) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < size; i++) { String tmp = (java.lang.Integer.toHexString(bytes[i] & 0XFF)); if (tmp.length() == 1) { sb.append("0" + tmp); } else { sb.append(tmp); } } hs = sb.toString().toUpperCase(); } } return hs; } public static byte[] hex2byte(byte[] b) { if ((b.length % 2) != 0) { return null; } 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; } /** * 十六进位格式字符串转二进制流。 * * @param hs String * @return byte[] */ public static byte[] hexString2Bytes (String hs) { byte[] bytes = null; if (hs != null) { final int size = (hs.length()) / 2; if (size > 0) { bytes = new byte[size]; for (int i = 0; i < size; i++) { String hsByte = hs.substring(i * 2, i * 2 + 2); byte b = 0; try { b = (byte) (Integer.parseInt(hsByte, 16)); } catch (java.lang.NumberFormatException e) { b = 0; } bytes[i] = b; } } } return bytes; } /** * 字符串解密 * * @param data * 字符串加密数据 * @param key * 密钥 * @param name * 算法名称 * @return * @throws Exception */ public static String decrypt(String data, String key, String name) { try { return new String(decrypt(hex2byte(data.getBytes()), string2Bytes(key), name)); } catch (Exception e) { } return null; } /** * 字符串解密 * * @param data * 字符串加密数据 * @param key * 密钥 * @param name * 算法名称 * @return * @throws Exception */ public static String decrypt(String data, byte[] key, String name) { try { return new String(decrypt(hex2byte(data.getBytes()),key, name)); } catch (Exception e) { } return null; } /** * 把字符串转化成 Unicode Bytes. * * @param s String * @return byte[] */ public static byte [] string2Bytes(String s) { byte[] bytes = null; if (s != null) { try { bytes = s.getBytes("utf-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } return bytes; } /** * 根据 Unicode Bytes 构造字符串. * * @param bytes byte[] * @return String */ public static String bytes2String (byte[] bytes) { String s = null; if (bytes != null) { try { s = new String(bytes, "utf-8"); } catch (Exception e) { e.printStackTrace(); } } return s; } /** * 字符串加密 * * @param data * 字符串数据 * @param key * 密钥 * @param name * 算法名称 * @throws Exception */ public static String encrypt(String data, byte[] key, String name) { try { return bytes2HexString(encrypt(data.getBytes(), key, name)); } catch (Exception e) { e.printStackTrace(); } return null; } /** * 字符串加密 * * @param data * 字符串数据 * @param key * 密钥 * @param name * 算法名称 * @throws Exception */ public static String encrypt(String data, String key, String name) { try { return bytes2HexString(encrypt(data.getBytes(), string2Bytes(key), name)); } catch (Exception e) { e.printStackTrace(); } return null; } }?