Android md5加密

public String md5(String s) {  
    try {  
        // Create MD5 Hash  
        MessageDigest digest = java.security.MessageDigest.getInstance("MD5");  
        digest.update(s.getBytes());  
        byte messageDigest[] = digest.digest();  

        // Create Hex String  
        StringBuffer hexString = new StringBuffer();  
        for (int i=0; i<messageDigest.length; i++)  
            hexString.append(Integer.toHexString(0xFF & messageDigest[i]));  
        return hexString.toString();  

    } catch (NoSuchAlgorithmException e) {  
        e.printStackTrace();  
    }  
    return "";  
}  
//或者部分加密  
public static String MD5_Hash(String s) { MessageDigest m = null;  

    try {  
            m = MessageDigest.getInstance("MD5");  
    } catch (NoSuchAlgorithmException e) {  
            e.printStackTrace();  
    }  

    m.update(s.getBytes(),0,s.length());  
    String hash = new BigInteger(1, m.digest()).toString(16);  
    return hash;  
}