MD5 simple instance, md5 instance

MD5 simple instance, md5 instance

When you click the button, you will first determine whether to log on for the first time. If you log on for the first time, a pop-up window for password setting will pop up. If you log on, a pop-up window will pop up.

The entered password is encrypted with MD5.

Package com.org. demo. wangfeng. demo; import com.org. wangfeng. r; import android. app. activity; import android. app. alertDialog; import android. content. sharedPreferences; import android. OS. bundle; import android. text. textUtils; import android. view. view; import android. widget. button; import android. widget. editText; import android. widget. toast; public class HomeActivity extends Activity {private Button bbButton; pr Ivate SharedPreferences mPref; @ Override protected void onCreate (Bundle savedInstanceState) {// TODO Auto-generated method stub super. onCreate (savedInstanceState); setContentView (R. layout. homeactivity); mPref = getSharedPreferences ("config", MODE_PRIVATE); bbButton = (Button) findViewById (R. id. bb_home); bbButton. setOnClickListener (new OnclickItem ();} private class OnclickItem implements View. on ClickListener {@ Override public void onClick (View arg0) {// TODO Auto-generated method stub String savedPassword = mPref. getString ("password", null); if (! TextUtils. isEmpty (savedPassword) {// enter the password pop-up window showPasswordInputDialog ();} else {// if no password is set, the pop-up window showPasswordSetDialog ();}}} /*** pop-up window for setting the password */private void showPasswordSetDialog () {AlertDialog. builder builder = new AlertDialog. builder (this); final AlertDialog dialog = builder. create (); View view = View. inflate (this, R. layout. dialog_set_password, null); dialog. setView (view, 0, 0, 0, 0); // set the margin to 0., Ensure that in 2. final EditText edPassWord = (EditText) view. findViewById (R. id. et_password); final EditText edPassWordConfirm = (EditText) view. findViewById (R. id. et_password_confirm); Button btnOK = (Button) view. findViewById (R. id. btn_ OK); Button btnCancel = (Button) view. findViewById (R. id. btn_cancel); btnOK. setOnClickListener (new View. onClickListener () {@ Override public void onClick (View arg0) {// TODO Auto-generated method stub String password = edPassWord. getText (). toString (); String passwordConfirm = edPassWordConfirm. getText (). toString (); if (! TextUtils. isEmpty (password )&&! PasswordConfirm. isEmpty () {// when the two inputs are the same if (password. equals (passwordConfirm) {Toast. makeText (HomeActivity. this, "Login successful", Toast. LENGTH_SHORT ). show (); // Save the password as mPref. edit (). putString ("password", MD5Utils. encode (password )). commit (); dialog. dismiss ();} else {Toast. makeText (HomeActivity. this, "2 inconsistent passwords", Toast. LENGTH_SHORT ). show () ;}} else {Toast. makeText (HomeActivity. this, "the input content cannot be blank", Toast. LENGTH_SHORT ). show () ;}}); btnCancel. setOnClickListener (new View. onClickListener () {@ Override public void onClick (View arg0) {// TODO Auto-generated method stub dialog. dismiss () ;}}); dialog. show ();}/*** enter password pop-up window */private void showPasswordInputDialog () {AlertDialog. builder builder = new AlertDialog. builder (this); final AlertDialog dialog = builder. create (); View view = View. inflate (this, R. layout. dialog_input_password, null); dialog. setView (view, 0, 0, 0, 0); final EditText etPassword = (EditText) view. findViewById (R. id. et_password); Button btnOk = (Button) view. findViewById (R. id. btn_ OK); Button btnCancel = (Button) view. findViewById (R. id. btn_cancel); btnOk. setOnClickListener (new View. onClickListener () {@ Override public void onClick (View arg0) {// TODO Auto-generated method s Tub String password = etPassword. getText (). toString (); if (! TextUtils. isEmpty (password) {String savedPassword = mPref. getString ("password", null); if (MD5Utils. encode (password ). equals (savedPassword) {Toast. makeText (HomeActivity. this, "Login successful", Toast. LENGTH_SHORT ). show (); dialog. dismiss ();} else {Toast. makeText (HomeActivity. this, "Incorrect password", Toast. LENGTH_SHORT ). show () ;}} else {Toast. makeText (HomeActivity. this, "the input content cannot be blank", Toast. LENGTH_SHORT ). show () ;}}); btnCancel. setOnClickListener (new View. onClickListener () {@ Override public void onClick (View arg0) {// TODO Auto-generated method stub dialog. dismiss () ;}}); dialog. show ();}}

Package com.org. demo. wangfeng. demo; import java. security. messageDigest; import java. security. noSuchAlgorithmException; public class MD5Utils {/*** md5 encryption ** @ param password * @ return */public static String encode (String password) {try {MessageDigest instance = MessageDigest. getInstance ("MD5"); // obtain the MD5 Algorithm object byte [] digest = instance. digest (password. getBytes (); // string encryption, returns the byte array StringBuffer sb = new StringBuffer (); for (byte B: digest) {int I = B & 0xff; // get the low-byte eight-bit valid value String hexString = Integer. toHexString (I); // convert the integer to hexadecimal if (hexString. length () <2) {hexString = "0" + hexString; // if it is 1 bit, add 0} sb. append (hexString);} return sb. toString ();} catch (NoSuchAlgorithmException e) {e. printStackTrace (); // if this algorithm does not exist, an exception is thrown and the return "" ;}} is not returned here "";}}

<? Xml version = "1.0" encoding = "UTF-8"?> <LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android" android: layout_width = "match_parent" android: layout_height = "match_parent" android: background = "# fff" android: orientation = "vertical"> <TextView android: id = "@ + id/textView1" android: layout_width = "match_parent" android: layout_height = "wrap_content" android: background = "#66ff6600" android: gravity = "center" android: padding = "10dp" android: text = "set password" android: textColor = "@ android: color/black "android: textSize =" 20sp "/> <EditText android: id =" @ + id/et_password "android: layout_width =" match_parent "android: layout_height = "wrap_content" android: hint = "enter the password" android: inputType = "textPassword"> </EditText> <EditText android: id = "@ + id/et_password_confirm" android: layout_width = "match_parent" android: layout_height = "wrap_content" android: hint = "Please enter the password again" android: inputType = "textPassword"> </EditText> <LinearLayout android: layout_width = "match_parent" android: layout_height = "wrap_content"> <Button android: id = "@ + id/btn_ OK" android: layout_width = "0dp" android: layout_height = "wrap_content" android: layout_weight = "1" android: text = "OK"/> <Button android: id = "@ + id/btn_cancel" android: layout_width = "0dp" android: layout_height = "wrap_content" android: layout_weight = "1" android: text = "cancel"/> </LinearLayout>View Code

 

In android, if (text = null | text. length () = 0) is encapsulated.
In android. text. TextUtils

Public static boolean isEmpty (CharSequence str) {if (str = null | str. length () = 0) return true; else return false;} so we can use

TextUtils.isEmpty(text)

Replace

if(text == null || text.length() == 0)