package com.pb;import java.io.UnsupportedEncodingException;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;import java.util.Scanner;/* * 驗證MD5 * 1.初始化MessageDigest信息摘要對象 * 2.傳入需要計算的字符串更新摘要信息 * 3.計算信息摘要 * 4.將byte[] 轉換為找度為32位的16進制字符串 */public class MD5 {  /*   * 生成md5 有傳入參數字符串   */  public void generateMD5(String input){        try {      //1.初始化MessageDigest信息摘要對象,并指定為MD5不分大小寫都可以      MessageDigest md=MessageDigest.getInstance("md5");       //2.傳入需要計算的字符串更新摘要信息，傳入的為字節數組byte[],      //將字符串轉換為字節數組使用getBytes()方法完成      //指定時其字符編碼 為utf-8      md.update(input.getBytes("utf-8"));       //3.計算信息摘要digest()方法      //返回值為字節數組      byte [] hashCode=md.digest();       //4.將byte[] 轉換為找度為32位的16進制字符串        //聲明StringBuffer對象來存放最后的值      StringBuffer sb=new StringBuffer();      //遍歷字節數組      for(byte b:hashCode){        //對數組內容轉化為16進制，        sb.append(Character.forDigit(b>>4&0xf, 16));        //換2次為32位的16進制        sb.append(Character.forDigit(b&0xf, 16));      }      System.out.println("加密后的結果是:"+sb.toString());    } catch (NoSuchAlgorithmException e) {      // TODO Auto-generated catch block      e.printStackTrace();    } catch (UnsupportedEncodingException e) {      // TODO Auto-generated catch block      e.printStackTrace();    }  }  public static void main(String[] args) {    //聲明加密MD5類的對象    MD5 md5=new MD5();    //使用Scanner來輸入一個字符    Scanner scanner=new Scanner(System.in);    System.out.println("請輸入要加密的內容:");    String input = scanner.nextLine();    //調用加密方法    md5.generateMD5(input);  }  }

package test.md5;import java.security.MessageDigest;public class MD5Util {  public final static String MD5(String s) {    char hexDigits[]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};        try {      byte[] btInput = s.getBytes();      // 獲得MD5摘要算法的 MessageDigest 對象      MessageDigest mdInst = MessageDigest.getInstance("MD5");      // 使用指定的字節更新摘要      mdInst.update(btInput);      // 獲得密文      byte[] md = mdInst.digest();      // 把密文轉換成十六進制的字符串形式      int j = md.length;      char str[] = new char[j * 2];      int k = 0;      for (int i = 0; i < j; i++) {        byte byte0 = md[i];        str[k++] = hexDigits[byte0 >>> 4 & 0xf];        str[k++] = hexDigits[byte0 & 0xf];      }      return new String(str);    } catch (Exception e) {      e.printStackTrace();      return null;    }  }  public static void main(String[] args) {    System.out.println(MD5Util.MD5("20121221"));    System.out.println(MD5Util.MD5("加密"));  }}

package other;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;/* * MD5 算法*/public class MD5 {    // 全局數組  private final static String[] strDigits = { "0", "1", "2", "3", "4", "5",      "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };  public MD5() {  }  // 返回形式為數字跟字符串  private static String byteToArrayString(byte bByte) {    int iRet = bByte;    // System.out.println("iRet="+iRet);    if (iRet < 0) {      iRet += 256;    }    int iD1 = iRet / 16;    int iD2 = iRet % 16;    return strDigits[iD1] + strDigits[iD2];  }  // 返回形式只為數字  private static String byteToNum(byte bByte) {    int iRet = bByte;    System.out.println("iRet1=" + iRet);    if (iRet < 0) {      iRet += 256;    }    return String.valueOf(iRet);  }  // 轉換字節數組為16進制字串  private static String byteToString(byte[] bByte) {    StringBuffer sBuffer = new StringBuffer();    for (int i = 0; i < bByte.length; i++) {      sBuffer.append(byteToArrayString(bByte[i]));    }    return sBuffer.toString();  }  public static String GetMD5Code(String strObj) {    String resultString = null;    try {      resultString = new String(strObj);      MessageDigest md = MessageDigest.getInstance("MD5");      // md.digest() 該函數返回值為存放哈希值結果的byte數組      resultString = byteToString(md.digest(strObj.getBytes()));    } catch (NoSuchAlgorithmException ex) {      ex.printStackTrace();    }    return resultString;  }  public static void main(String[] args) {    MD5 getMD5 = new MD5();    System.out.println(getMD5.GetMD5Code("000000"));  }}