/**
 * 
 */
package com.manage.encrypt;

import java.security.MessageDigest;

/**
 * <p>Title:MD5 </p>
 * <p>Description: </p>
 * <p>Company: </p> 
 * @author hu
 * @date
 */
public class MD5 {
	// MD5加码。32位  
	 public static String MD5(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();  
	 }  
	  
	 // 可逆的加密算法  
	 public static String KL(String inStr) {  
	  // String s = new 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;  
	 }  
	  
	 // 加密后解密  
	 public static String JM(String inStr) {  
	  char[] a = inStr.toCharArray();  
	  for (int i = 0; i < a.length; i++) {  
	   a[i] = (char) (a[i] ^ 't');  
	  }  
	  String k = new String(a);  
	  return k;  
	 }  
	   
	 // 测试主函数  
	 public static void main(String args[]) {  
	  String s = new String("a");  
	  System.out.println("原始：" + s);  
	  System.out.println("MD5后：" + MD5(s));  
	  System.out.println("MD5后再加密：" + KL(MD5(s)));  
	  System.out.println("解密为MD5后的：" + JM(KL(MD5(s))));  
	 } 

}
