Read file from Internal Storage via FileInputStream

Read file from Internal Storage via FileInputStream -

The file in Internal Storage can be read using read() method of FileInputStream class.

Further work on last exercise "List the saved files in Internal Storage"; once any item in the ListView of saved files is clicked, the file will be opened using FileInputStream.read(), and the content will be displayed in a custom dialog.

package com.exercise.AndroidInternalStorage;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

public class AndroidInternalStorageActivity extends Activity {
 
 EditText edFileName, edContent;
 Button btnSave;
 ListView listSavedFiles;
 
 String[] SavedFiles;
 
   /** Called when the activity is first created. */
   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);
       edFileName = (EditText)findViewById(R.id.filename);
       edContent = (EditText)findViewById(R.id.content);
    btnSave = (Button)findViewById(R.id.save);
    listSavedFiles = (ListView)findViewById(R.id.list);
    
    ShowSavedFiles();
    
    btnSave.setOnClickListener(new Button.OnClickListener(){

   @Override
   public void onClick(View arg0) {
    // TODO Auto-generated method stub
    String fileName = edFileName.getText().toString();
    String content = edContent.getText().toString();
    
    FileOutputStream fos;
    try {
     fos = openFileOutput(fileName, Context.MODE_PRIVATE);
     fos.write(content.getBytes());
     fos.close();
     
     Toast.makeText(
       AndroidInternalStorageActivity.this,
       fileName + " saved",
       Toast.LENGTH_LONG).show();
     
    } catch (FileNotFoundException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    } catch (IOException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
    
    ShowSavedFiles();
    
   }});
    
    listSavedFiles.setOnItemClickListener(listSavedFilesOnItemClickListener);
    
   }
  
   void ShowSavedFiles(){
    SavedFiles = getApplicationContext().fileList();
    ArrayAdapter<String> adapter
    = new ArrayAdapter<String>(this,
      android.R.layout.simple_list_item_1,
      SavedFiles);

    listSavedFiles.setAdapter(adapter);
   }
  
   OnItemClickListener listSavedFilesOnItemClickListener
   = new OnItemClickListener(){

  @Override
  public void onItemClick(AdapterView<?> parent, View view, int position,
    long id) {
   // TODO Auto-generated method stub
   String clickedFile = (String) parent.getItemAtPosition(position);
   OpenFileDialog(clickedFile);
  }
    
   };
  
   void OpenFileDialog(String file){
    
    //Read file in Internal Storage
    FileInputStream fis;
    String content = "";
    try {
     fis = openFileInput(file);
     byte[] input = new byte[fis.available()];
     while (fis.read(input) != -1) {}
     content += new String(input);
    } catch (FileNotFoundException e) {
     e.printStackTrace();
    } catch (IOException e) {
     e.printStackTrace(); 
    }
    
    //Create a custom Dialog
    AlertDialog.Builder fileDialog
    = new AlertDialog.Builder(AndroidInternalStorageActivity.this);
    fileDialog.setTitle(file);
    
    TextView textContent = new TextView(AndroidInternalStorageActivity.this);
    textContent.setText(content);
       LayoutParams textViewLayoutParams
        = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
       textContent.setLayoutParams(textViewLayoutParams);
      
       fileDialog.setView(textContent);
      
       fileDialog.setPositiveButton("OK", null);
      
       fileDialog.show();
   }
}

Download the files.

next:
- Delete file in Internal Storage