java md5 3
2011-11-09 20:17 youxin 阅读(282) 评论(0) 编辑 收藏 举报import java.security.*;
public class MD5{
//十六进制下数字到字符的映射数组
private final static String[] hexDigits =
{"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};
/**把inputString加密*/
public static String md5(String inputString){
return encodeByMD5(inputString);
}
/**
* 验证输入的密码是否正确
* @param password 真正的密码(加密后的真密码)
* @param inputString 输入的字符串
* @return 验证结果,boolean类型
*/
public static boolean compare(String md5Str,String inputString){
if(md5Str.equals(encodeByMD5(inputString))){
return true;
}else{
return false;
}
}
/**对字符串进行MD5编码*/
private static String encodeByMD5(String originString){
if(originString != null){
try{
//创建具有指定算法名称的信息摘要
MessageDigest md = MessageDigest.getInstance("MD5");
//使用指定的字节数组对摘要进行最后更新,然后完成摘要计算
byte[] results = md.digest(originString.getBytes());
//将得到的字节数组变成字符串返回
String resultString = byteArrayToHexString(results);
return resultString.toUpperCase();
}catch(Exception ex){
ex.printStackTrace();
}
}
return null;
}
/**
* 轮换字节数组为十六进制字符串
* @param b 字节数组
* @return 十六进制字符串
*/
private static String byteArrayToHexString(byte[] b){
StringBuffer resultSb = new StringBuffer();
for(int i=0;i<b.length;i++){
resultSb.append(byteToHexString(b[i]));
}
return resultSb.toString();
}
/**
* 将一个字节转化成十六进制形式的字符串
*/
private static String byteToHexString(byte b){
int n = b;
if(n<0)
n=256+n;
int d1 = n/16;
int d2 = n%16;
return hexDigits[d1] + hexDigits[d2];
}
public static void main(String[] args){
String password = MD5.md5("admin");
System.out.println("对admin用MD5摘要后的字符串:"+password);
String inputString = "tianshi0253";
System.out.println("tianshi0253与密码匹配?"+MD5.compare(password, inputString));
inputString = "admin";
System.out.println("admin与密码匹配?"+MD5.compare(password, inputString));
}
}