数字摘要(MD5)

package com.test;

import java.security.MessageDigest;

public class MD5 {

	/**
	 * @param args
	 */
	public static void main(String[] args) throws Exception {
		String md5 = md5("测试数据");
		System.out.println(md5);
		
	}
	
	public static String md5(String data) throws Exception{
		String md5 = "";
		MessageDigest md = MessageDigest.getInstance("MD5");
		md.update(data.getBytes());
		byte[] rs = md.digest();
		md5 = toHex(rs);
		return md5;
	}
	
	public static String toHex(byte[] rs){
		StringBuilder sb = new StringBuilder("");
		for (int i = 0; i < rs.length; i++) {
			int h = ((rs[i]>>4) & 0x0f);
			int l = rs[i] & 0x0f;

			sb.append(h > 9 ? (char)((h - 10) + 'a') : (char)(h + '0'));
			sb.append(l > 9 ? (char)((l - 10) + 'a') : (char)(l + '0'));
		}
		return sb.toString();
	}

}