Io of Android data storage

Data storage is unavoidable in Android development, and today we talk about how to use IO streams to store data.

Here we actually operate the IO stream by simulating a small demo of the QQ landing interface.

Function Description: Click the button can save user input user name and password, when the click Remember Password, also can be opened in the application the second time, echo the user name and password

1. The code of the layout file here is not posted, see

2.mainactivity.java

 PackageCom.example.viewswitchtest;ImportJava.io.BufferedReader;ImportJava.io.File;ImportJava.io.FileInputStream;ImportJava.io.FileNotFoundException;ImportJava.io.FileOutputStream;ImportJava.io.InputStreamReader;ImportJava.util.ArrayList;ImportJava.util.List;ImportAndroid.os.Bundle;ImportAndroid.os.Environment;Importandroid.app.Activity;Importandroid.graphics.drawable.Drawable;ImportAndroid.telephony.SmsManager;ImportAndroid.util.Log;ImportAndroid.view.Menu;ImportAndroid.view.View;ImportAndroid.view.View.OnClickListener;ImportAndroid.widget.Button;ImportAndroid.widget.CheckBox;ImportAndroid.widget.EditText;ImportAndroid.widget.Toast; Public  class mainactivity extends Activity {    PrivateEditText Editaccount;PrivateEditText editpwd;PrivateButton Btnlogin;PrivateCheckBox checkbox;@Override    protected void onCreate(Bundle savedinstancestate) {Super. OnCreate (Savedinstancestate); Setcontentview (R.layout.activity_main);//Account EditEditaccount = (EditText) Findviewbyid (R.id.edit_account);//Password editEditpwd = (EditText) Findviewbyid (R.ID.EDIT_PWD);//Login buttonBtnlogin = (Button) Findviewbyid (R.id.btn_login);//Remember account number and password checkboxcheckbox = (checkbox) Findviewbyid (R.id.checkbox);//Echo account and passwordReadaccountandpwd (); Btnlogin.setonclicklistener (NewOnclicklistener () {@Override             Public void OnClick(View arg0) {if(Checkbox.ischecked ())                    {String account = Editaccount.gettext (). toString (); String pwd = Editpwd.gettext (). toString ();//Android to prevent developer handwriting path errors, the gate provides two APIs                    //Getfilesdir () and Path: data/data/Project package name/files                    //Getcachedir () and Path: data/data/Project package name/cacheFile File =NewFile (Getfilesdir (),"Info.txt");Try{FileOutputStream FOS =NewFileOutputStream (file); Fos.write (account +"-"+ pwd). GetBytes ());//Save format as "Account-password" for easy segmentationFos.close (); }Catch(Exception e)                    {E.printstacktrace (); }} toast.maketext (mainactivity. This,"Login Success", Toast.length_long). Show ();    }        }); }/** * echo user name and password */    Private void readaccountandpwd() {File File =NewFile (Getfilesdir (),"Info.txt");if(File.exists ()) {Try{FileInputStream FIS =NewFileInputStream (file); BufferedReader reader =NewBufferedReader (NewInputStreamReader (FIS));                String text = Reader.readline (); string[] Infos = Text.split ("-");//Echo InformationEditaccount.settext (infos[0]); Editpwd.settext (infos[1]);                Fis.close ();            Reader.close (); }Catch(Exception e) {//TODO auto-generated catch blockE.printstacktrace (); }        }    }}

3. Enter the account number and password, click the login button, we can see in the Ddms file explore in the saved TXT format files:

4. Export the file, open the verification through a text editor, the account password is correct:

You can see that the account and password are saved correctly and in the correct format.

5. Close the app and open it again

You can see that the data can be correctly echoed into the input box,:-D!!!

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

Io of Android data storage