MD5Util.java

package tangjie.qipai.majiang.logic.weixin;

import java.security.MessageDigest;

public class MD5Util {

	 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" };  
	  
}