activity_main.xmlMainActivity.java
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.codinginflow.internalstorageexample.MainActivity"> <EditText android:id="@+id/edit_text" android:layout_width="match_parent" android:layout_height="200dp" /> <Button android:id="@+id/button_save" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@+id/edit_text" android:layout_centerHorizontal="true" android:layout_marginTop="16dp" android:text="save" android:onClick="save"/> <Button android:id="@+id/button_load" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignStart="@+id/button_save" android:layout_below="@+id/button_save" android:layout_marginTop="17dp" android:text="load" android:onClick="load"/> </RelativeLayout>
package com.codinginflow.internalstorageexample; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.EditText; import android.widget.Toast; import java.io.BufferedReader; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStreamReader; public class MainActivity extends AppCompatActivity { private static final String FILE_NAME = "example.txt"; EditText mEditText; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mEditText = findViewById(R.id.edit_text); } public void save(View v) { String text = mEditText.getText().toString(); FileOutputStream fos = null; try { fos = openFileOutput(FILE_NAME, MODE_PRIVATE); fos.write(text.getBytes()); mEditText.getText().clear(); Toast.makeText(this, "Saved to " + getFilesDir() + "/" + FILE_NAME, Toast.LENGTH_LONG).show(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { if (fos != null) { try { fos.close(); } catch (IOException e) { e.printStackTrace(); } } } } public void load(View v) { FileInputStream fis = null; try { fis = openFileInput(FILE_NAME); InputStreamReader isr = new InputStreamReader(fis); BufferedReader br = new BufferedReader(isr); StringBuilder sb = new StringBuilder(); String text; while ((text = br.readLine()) != null) { sb.append(text).append("\n"); } mEditText.setText(sb.toString()); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { if (fis != null) { try { fis.close(); } catch (IOException e) { e.printStackTrace(); } } } } }