md5加密算法

package com.parwa.web.util;

import java.security.MessageDigest;
import java.util.Iterator;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
/**
 * MD5加密工具类
 * @author win
 *
 */
public class MD5Utils {
	
	@SuppressWarnings("rawtypes")
	public static String createSign(SortedMap<Object, Object> parameters, String key) {
		StringBuffer sb = new StringBuffer();
		Set es = parameters.entrySet();// 所有参与传参的参数按照accsii排序（升序）
		Iterator it = es.iterator();
		while (it.hasNext()) {
			Map.Entry entry = (Map.Entry) it.next();
			String k = (String) entry.getKey();
			Object v = entry.getValue();
			if (null != v && !"".equals(v) && !"sign".equals(k) && !"key".equals(k)) {
				sb.append(k + "=" + v + "&");
			}
		}
		sb.append("key=" + key);
		String sign = MD5Encode(sb.toString(), "UTF-8").toUpperCase();
		return sign;
	}

	/**
	 * MD5加密密文返回
	 * */
	public static String getMd5Value(String sSecret) {
		String result = null;
		try {
			MessageDigest bmd5 = MessageDigest.getInstance("MD5");
			bmd5.update(sSecret.getBytes());
			StringBuffer buf = new StringBuffer();
			try {
				result = byte2hex(bmd5.digest(buf.toString().getBytes("UTF-8")));
			} catch (Exception e) {
				e.printStackTrace();
			}
			return result;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * 二进制转字符串
	 */
	private static String byte2hex(byte[] b) {
		StringBuffer hs = new StringBuffer();
		String stmp = "";
		for (int n = 0; n < b.length; n++) {
			stmp = (Integer.toHexString(b[n] & 0XFF));
			if (stmp.length() == 1)
				hs.append("0").append(stmp);
			else
				hs.append(stmp);
		}
		return hs.toString().toUpperCase(Locale.ENGLISH);
	}
	
	/**
	 * **验证
	 */
	
	public static String  SmsPwdMd5(String plainText ) { 
		try { 
				MessageDigest md = MessageDigest.getInstance("MD5"); 
				md.update(plainText.getBytes()); 
				byte b[] = md.digest(); 
		
				int i; 
		
				StringBuffer buf = new StringBuffer(""); 
				for (int offset = 0; offset < b.length; offset++) { 
					i = b[offset]; 
					if(i<0) i+= 256; 
					if(i<16) 
					buf.append("0"); 
					buf.append(Integer.toHexString(i)); 
				} 
				return buf.toString();
		}
		catch (Exception e) { 
			// TODO Auto-generated catch block 
			e.printStackTrace(); 
			return "";
		} 
	}
	
	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();
	}

	private static String byteToHexString(byte b) {
		int n = b;
		if (n < 0)
			n += 256;
		int d1 = n / 16;
		int d2 = n % 16;
		return hexDigits[d1] + hexDigits[d2];
	}

	public static String MD5Encode(String origin, String charsetname) {
		String resultString = null;
		try {
			resultString = new String(origin);
			MessageDigest md = MessageDigest.getInstance("MD5");
			if (charsetname == null || "".equals(charsetname))
				resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
			else
				resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
		} catch (Exception exception) {
		}
		return resultString;
	}

	private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d",
			"e", "f" };

	public static void main(String[] args) {
		System.out.println(getMd5Value("test"));
	}

}