java中使用MD5加密明文

        密码等重要信息入数据库的时候考虑数据的安全性，会将明文的密码加密，其中MD5就是其中的一种算法，在java中的MessageDigest类就是MD5的具体实现，在将转成的字节数组转成十六进制，起到加密的作用。

例子如下：

package MD5加密;

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

/**
 * MD5
 * @author Tms
 *
 */
public class Test {
	
	static String[] hex = {"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"};
	
	public static void main(String[] args) throws NoSuchAlgorithmException {
		String password = "tms123456";
		String passwordByMD5 = encodeByMD5(password);
		System.out.println("password:"+password);
		System.out.println("passwordByMD5:"+passwordByMD5);
	}

	private static String encodeByMD5(String password) throws NoSuchAlgorithmException {
		MessageDigest digest = MessageDigest.getInstance("md5");
		byte[] results = digest.digest(password.getBytes());
		return byteArrayToString(results);
	}

	private static String byteArrayToString(byte[] results) {
		StringBuffer sb = new StringBuffer();
		for(int i=0;i<results.length;i++) {
			//per byte to string
			sb.append(byteToString(results[i]));
		}
		return sb.toString();
	}

	//per byte to String (Algorithms)
	private static Object byteToString(byte b) {
		int n = b;
		if(n<0) {
			n = 256+n;
		}
		int d1 = n/16;
		int d2 = n%16;		
		return hex[d1]+hex[d2];
	}
}

   

     运行结果：

     

password:tms123456
passwordByMD5:B76CDA5AEBD39488E8F15CE1599BEC83