MD5工具类代码如下
import java.security.MessageDigest;public class MD5Utils {/**** MD5加码 生成32位md5码*/ public static String string2MD5(String inStr){ MessageDigest md5 = null; try{ md5 = MessageDigest.getInstance("MD5"); }catch (Exception e){ System.out.println(e.toString()); e.printStackTrace(); return ""; } char[] charArray = inStr.toCharArray(); byte[] byteArray = new byte[charArray.length]; for (int i = 0; i < charArray.length; i++) byteArray[i] = (byte) charArray[i]; byte[] md5Bytes = md5.digest(byteArray); StringBuffer hexValue = new StringBuffer(); for (int i = 0; i < md5Bytes.length; i++){ int val = ((int) md5Bytes[i]) & 0xff; if (val < 16) hexValue.append("0"); hexValue.append(Integer.toHexString(val)); } return hexValue.toString(); } /*** 加密解密算法 执行一次加密，两次解密*/ public static String convertMD5(String inStr){ char[] a = inStr.toCharArray(); for (int i = 0; i < a.length; i++){ a[i] = (char) (a[i] ^ 't'); } String s = new String(a); return s; } // 测试主函数 public static void main(String args[]) { String s = new String("1111"); System.out.println("原始：" + s); System.out.println("MD5后：" + string2MD5(s)); System.out.println("加密的：" + convertMD5(s)); System.out.println("解密的：" + convertMD5(convertMD5(s))); } }
原始：1111
MD5后：b59c67bf196a4758191e42f76670ceba
加密的：EEEE
解密的：1111
