Java加密算法

来源：互联网发布：学生成绩管理c语言代码编辑：程序博客网时间：2024/04/30 02:48

package sort;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MessageCheck {

public static String hasString(byte[] b){
   String has = "", tmp = "";
   for (int i = 0; i < b.length; i++){
     // 以十六进制的无符号整数形式返回一个整数参数的字符串表示形式
     tmp=(java.lang.Integer.toHexString(b[i] & 0XFF));
     if (tmp.length() == 1)    has = has + "0" + tmp;   else    has = has + tmp;   if (i < b.length - 1) has = has + ":";
     }
   return has.toUpperCase();
}

public static void main(String[] args) {
   String info1 = "admin";
   //String info1 = "Hello World!";
   String info2 = "Hello World!";
         try {
     // 生成 MessageDigest 实例，确定计算方法
     //MessageDigest md1 = MessageDigest.getInstance("SHA-1");
     MessageDigest md1 = MessageDigest.getInstance("MD5");

     // 添加要计算的摘要信息
    md1.update(info1.getBytes()); // transform parameter to byte[]
    // 完成哈希计算,返回计算得到的摘要(对于MD5是16位,SHA是20位)
    byte[] digA = md1.digest();
    MessageDigest md2 = MessageDigest.getInstance("SHA-1");
    md2.update(info2.getBytes());
    byte[] digB = md2.digest();      // 比较两信息是否相等
     if (md2.isEqual(digA, digB)){
      System.out.println("两信息相等，检查正常！");
     System.out.println(hasString(digA) + "/n" + hasString(digB));
    }else {
     System.out.println("两信息不相等，摘要不相同！");
     System.out.println(hasString(digA) + "/n" + hasString(digB));
    }
   }catch (NoSuchAlgorithmException e) {
     System.out.println("非法摘要算法！");
     e.printStackTrace();
     }
  }

}