Android login implementation, store data to/data/data/package name/info.txt

1. A simple login interface layout code is as follows:

@1 with linear layout and relative layout

@2 linear layout with vertical arrangement

<?XML version= "1.0" encoding= "Utf-8"?><LinearLayoutxmlns:android= "Http://schemas.android.com/apk/res/android"Xmlns:tools= "Http://schemas.android.com/tools"android:orientation= "vertical"Android:layout_width= "Match_parent"Android:layout_height= "Match_parent"Tools:context= "Com.market.login.MainActivity">    <EditTextAndroid:id= "@+id/et_name"Android:layout_margintop= "150DP"Android:layout_width= "Match_parent"Android:layout_height= "Wrap_content" />    <EditTextAndroid:id= "@+id/et_pwd"Android:layout_margintop= "20DP"Android:layout_width= "Match_parent"Android:layout_height= "Wrap_content" />        <RelativelayoutAndroid:layout_width= "Match_parent"Android:layout_margintop= "20DP"Android:layout_height= "Wrap_content">            <CheckBoxAndroid:id= "@+id/cb"Android:layout_width= "Wrap_content"Android:layout_marginleft= "10DP"android:layout_centervertical= "true"Android:layout_height= "Wrap_content"Android:text= "Remember Password"/>            <ButtonAndroid:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "Login"Android:layout_marginright= "50DP"Android:layout_centerhorizontal= "true"Android:layout_alignparentright= "true"/>        </Relativelayout></LinearLayout>

The interface effect is as follows:

2. Code logic, divided into Mainactivity class and Saveuserinfo tool class

Three steps: Initializing the UI, initializing the data (loading), initializing the controller

@1 main code is as follows

 PackageCom.market.login;Importandroid.app.Activity;ImportAndroid.os.Bundle;Importandroid.text.TextUtils;ImportAndroid.util.Log;ImportAndroid.view.View;ImportAndroid.widget.Button;ImportAndroid.widget.CheckBox;ImportAndroid.widget.EditText;ImportAndroid.widget.Toast;ImportJava.util.Map;Import StaticCOM.MARKET.LOGIN.R.ID.CB; Public classMainactivityextendsActivity {PrivateButton btn; PrivateEditText Et_name; PrivateEditText et_pwd; PrivateCheckBox CB; @Overrideprotected voidonCreate (Bundle savedinstancestate) {Super. OnCreate (savedinstancestate);        Setcontentview (R.layout.activity_main);        Initview ();    LoadData (); }     Public voidLogin (View v) {String name=Et_name.gettext (). toString (). Trim (); String Password=Et_pwd.gettext (). toString (). Trim (); if(Textutils.isempty (name) | |textutils.isempty (password)) {Toast.maketext ( This, "User name and password cannot be empty", Toast.length_short). Show (); }Else{            if(Cb.ischecked ()) {//If you save your password and name//start saving, save to file, next come in and read this file firstSaveuserinfo.saveinfo (Name,password,true); //submit a user name and password to the serverLOG.V ("Maintivity", "Submit user name and password to server"); }Else{saveuserinfo.saveinfo ("","",false); //submit a user name and password directly to the serverLOG.V ("Maintivity", "Submit user name and password directly to the server"); }        }    }     Public voidInitview () {btn=(Button) Findviewbyid (R.ID.BTN); Et_name=(EditText) Findviewbyid (r.id.et_name); Et_pwd=(EditText) Findviewbyid (R.ID.ET_PWD); CB=(CheckBox) Findviewbyid (R.ID.CB); }     Public voidLoadData () {Map<string, string> info =Saveuserinfo.readinfo (); if(Info! =NULL) {Et_name.settext (Info.get ("Name")); Et_pwd.settext (Info.get ("Password")); Cb.setchecked (Info.get ("isChecked"). Equals ("true"));//If the information is saved, he checked it last time .        }    }}

@2 tool class for saving data to/data/data/package name/Next file

 PackageCom.market.login;ImportAndroid.util.Log;ImportJava.io.BufferedReader;ImportJava.io.File;ImportJava.io.FileInputStream;Importjava.io.FileNotFoundException;ImportJava.io.FileOutputStream;Importjava.io.IOException;ImportJava.io.InputStreamReader;ImportJava.util.HashMap;ImportJava.util.Map;/*** Save user information class, implement save user information to file * Created by Administrator on 2017/6/14.*/ Public classSaveuserinfo {/*Save User Information * Name: username * Password: password * isChecked: Check Save password * **/     Public Static BooleanSaveinfo (String name,string pwd,BooleanisChecked) {String Info= name+ "#" +pwd+ "#" +isChecked; File File=NewFile ("/data/data/com.market.login/info.txt"); FileOutputStream Fos=NULL; Try{fos=Newfileoutputstream (file);            Fos.write (Info.getbytes ()); return true; } Catch(FileNotFoundException e) {e.printstacktrace (); } Catch(IOException e) {e.printstacktrace (); }finally {            if(Fos! =NULL) {                Try{fos.close (); } Catch(IOException e) {e.printstacktrace (); }            }            return false; }    }    /*Read user Information*/     Public StaticMap<string,string>Readinfo () {Map<String,String> map =NULL; File File=NewFile ("/data/data/com.market.login/info.txt"); if(!file.exists ()) {            returnmap; } FileInputStream FIS=NULL; BufferedReader BR=NULL; Try{FIS=Newfileinputstream (file); BR=NewBufferedReader (NewInputStreamReader (FIS)); String Info=Br.readline (); LOG.E ("Saveuserinfo", info); String[] Split= Info.split ("#"); Map=NewHashmap<string,string>(); Map.put ("Name", Split[0]);//Save the Read user name and password into the mapMap.put ("Password", split[1]); Map.put ("IsChecked", split[2]); } Catch(FileNotFoundException e) {e.printstacktrace (); } Catch(IOException e) {e.printstacktrace (); }finally {            if(FIS! =NULL) {                Try{fis.close (); } Catch(IOException e) {e.printstacktrace (); }            }            if(BR! =NULL) {                Try{br.close (); } Catch(IOException e) {e.printstacktrace (); }            }            returnmap; }    }}

3. Operation effect, divided into three kinds of situations

@1 User name and password fill in a blank

@2 does not check the checkbox effect and log back in after exiting the effect

@3 check after effect and exit re-login effect

　　

　　

Android login implementation, store data to/data/data/package name/info.txt