1、md5新建類：

public class MD5 {public static String toMD5(String str) {    str="zgqrxlb"+str;    byte[] source = new byte[0];    try {        source = str.getBytes("ascii");    } catch (UnsupportedEncodingException e) {        e.PRintStackTrace();    }    MessageDigest md = null;    try {        md = MessageDigest.getInstance("MD5");    } catch (NoSuchAlgorithmException e) {        e.printStackTrace();    }    md.update(source);    StringBuffer buf = new StringBuffer();    for (byte b : md.digest())        buf.append(String.format("%02x", b & 0xff));//%02x    return buf.toString().toUpperCase(Locale.getDefault()).substring(0,26);}}
2、在需要加密（這里是給密碼加密）的地方調用上面的工具類
String ss= MD5.toMD5(et_register_passWord.getText().toString()); mPassWord=MD5.toMD5(ss+"a!b@c#");  Log.d("mPassWord",mPassWord);