Delete file in Internal Storage

The method deleteFile() delete the given private file associated with this Context's application package.

Modify the code in last exercise "Read file from Internal Storage via FileInputStream", add OnClickListener DeleteListener called by an additional button "Delete" inside fileDialog.

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.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
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(final 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);
        
        //Delete file in Internal Storage
        OnClickListener DeleteListener = new OnClickListener(){

   @Override
   public void onClick(DialogInterface dialog, int which) {
    // TODO Auto-generated method stub
    deleteFile(file);
    Toast.makeText(
      AndroidInternalStorageActivity.this, 
      file + " deleted", 
      Toast.LENGTH_LONG).show();
    ShowSavedFiles();
   }
 
        };
  fileDialog.setNeutralButton("DELETE", DeleteListener);
        
        fileDialog.show();
    }
}

Download the files.