Shulou(Shulou.com)06/02 Report--

This article mainly explains "Android how to achieve file storage", the content of the article is simple and clear, easy to learn and understand, the following please follow the editor's ideas slowly in depth, together to study and learn "Android how to achieve file storage" bar!

1. File storage case

Public class TestActivity extends AppCompatActivity {private EditText mFileEdit; @ Override protected void onCreate (Bundle savedInstanceState) {super.onCreate (savedInstanceState); setContentView (R.layout.activity_test); initView ();} private void initView () {mFileEdit = findViewById (R.id.fileEdit); String inputText = load (); if (! TextUtils.isEmpty (inputText)) {mFileEdit.setText (inputText) MFileEdit.setSelection (inputText.length ()); Toast.makeText (this, "Restoring succeeded", Toast.LENGTH_SHORT). Show ();} @ Override protected void onDestroy () {super.onDestroy (); String inputText = mFileEdit.getText () .toString (); save (inputText) } / / read data from file public void save (String inputText) {FileOutputStream outputStream = null; BufferedWriter writer = null; try {outputStream = openFileOutput ("data", Context.MODE_PRIVATE); writer = new BufferedWriter (new OutputStreamWriter (outputStream)); writer.write (inputText);} catch (IOException e) {e.printStackTrace () } finally {try {if (writer! = null) {writer.close ();}} catch (IOException e) {e.printStackTrace () Store the file in a file public String load () {FileInputStream inputStream = null; BufferedReader reader = null; StringBuilder builder = new StringBuilder (); try {inputStream = openFileInput ("data"); reader = new BufferedReader (new InputStreamReader (inputStream)); String line = "" While ((line = reader.readLine ())! = null) {builder.append (line);}} catch (IOException e) {e.printStackTrace ();} finally {if (reader! = null) {try {reader.close () } catch (IOException e) {e.printStackTrace ();} return builder.toString ();}}

Running result, Pass

2. SharePreferences storage case

Public class SharePfsActivity extends AppCompatActivity implements View.OnClickListener {private static final String TAG = "SharePfsActivity"; private Button mSharedData; private Button mRestoreData; @ Override protected void onCreate (Bundle savedInstanceState) {super.onCreate (savedInstanceState); setContentView (R.layout.activity_shared_pfs); initView ();} private void initView () {mSharedData = findViewById (R.id.sharedBtn); mSharedData.setOnClickListener (this) MRestoreData = findViewById (R.id.restoreBtn); mRestoreData.setOnClickListener (this);} @ Override public void onClick (View view) {switch (view.getId ()) {case R.id.sharedBtn: sharedData (); break; case R.id.restoreBtn: restoreData (); break Default: break;}} private void sharedData () {SharedPreferences.Editor editor = getSharedPreferences ("shareData", MODE_PRIVATE). Edit (); editor.putString ("name", "meritorious"); editor.putString ("type", "Movie"); editor.apply () } private void restoreData () {SharedPreferences preferences = getSharedPreferences ("shareData", MODE_PRIVATE); String name = preferences.getString ("name", ""); String type = preferences.getString ("type", ""); Log.d (TAG, "name:" + name + ", type:" + type);}}

Running result, Pass

3. Log in to the page to remember username and pwd

Activity_login.xml file

LoginActivity .class

Public class LoginActivity extends AppCompatActivity {private static final String TAG = "LoginActivity"; private Button mLogin; private CheckBox mRemember; private EditText mUsername; private EditText mPwd; private SharedPreferences mSharedPs; private SharedPreferences.Editor mEditor; @ Override protected void onCreate (Bundle savedInstanceState) {super.onCreate (savedInstanceState); setContentView (R.layout.activity_login); initView ();} private void initView () {mSharedPs = PreferenceManager.getDefaultSharedPreferences (this) MUsername = findViewById (R.id.username); mPwd = findViewById (R.id.pwd); mRemember = findViewById (R.id.remember); mLogin = findViewById (R.id.login); boolean isRemember = mSharedPs.getBoolean ("remember_pwd", false) If (isRemember) {/ / set the account and password to the text box mUsername.setText (mSharedPs.getString ("username", ")); mPwd.setText (mSharedPs.getString (" pwd ",")); mRemember.setChecked (true) } mLogin.setOnClickListener (new View.OnClickListener () {@ Override public void onClick (View v) {String username = mUsername.getText () .toString (); String pwd = mPwd.getText () .toString () / / if the account: admin and password: 123456, the login is considered successful if (username.equals ("admin") & & pwd.equals ("123456")) {mEditor = mSharedPs.edit () / / check whether the check box is selected if (mRemember.isChecked ()) {mEditor.putString ("username", username); mEditor.putString ("pwd", pwd); mEditor.putBoolean ("remember_pwd", true) } else {mEditor.clear ();} mEditor.apply (); Intent intent = new Intent (LoginActivity.this, MainActivity.class); startActivity (intent); finish () } else {Log.d (TAG, "user name or password entered incorrectly, please re-enter");});}}

Running result, Pass

Thank you for reading, the above is the content of "how to achieve file storage in Android". After the study of this article, I believe you have a deeper understanding of how to achieve file storage in Android, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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