How to store ArrayList in File exmaple in android

Array List stored/ synchronized with Object File instead of using Sqlite Database.

Purpose:

The Array List Object stored into file as Object File permanently. The Array List object initializes with the Object File. So for this method we are avoiding following problems.

• No needs to use the SQlite Database for the entire Array list storage.
• No need to read the Text file and parse and load into the Array list, if we are storing as normal text file.

Source Code:

package cem.net;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.text.SimpleDateFormat;

import java.util.ArrayList;

import java.util.Date;

import java.util.HashMap;

import java.util.List;

import android.app.Activity;

import android.os.Bundle;

import android.util.Log;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

public class Main extends Activity {

      final static int READ=1;

      final static int WRITE=2;

      private List<HashMap<String, String>> ListMaps=

            new ArrayList<HashMap<String, String>>();

      private String FileName="CData";

      private String F_Path="";

     

      Button add_b,save_b;

      EditText d_name_et;

      TextView dip_tv;

     

     

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        add_b =(Button)findViewById(R.id.d_add);

        d_name_et=(EditText)findViewById(R.id.d_name);

        save_b =(Button)findViewById(R.id.d_save);

        test_b=(Button)findViewById(R.id.d_test);

        add_b.setOnClickListener(ButtonClickL);

        save_b.setOnClickListener(ButtonClickL);       

        dip_tv =(TextView)findViewById(R.id.d_dip);

       // F_Path=this.getApplicationContext().getFilesDir().getParent()+"/"+FileName;

        F_Path=FileName;

        Log.d("F_Path", " File Path :"+F_Path);

        load_data();

       

    }

   

   

    public void Add_Data(){

      Log.d("Add", "Add Data Calling");        

      HashMap<String, String> map= new HashMap<String, String>();        

      map.put("Name",d_name_et.getText().toString() );

      ListMaps.add(map);

      d_name_et.setText("");

      Disp_Data();

    }

    public void Save_Data(){

      Log.d("Save", "Save Data Calling");

     

      try {

                  writeListToFile((ArrayList<HashMap<String, String>>) ListMaps);

            } catch (Exception e) {

                  Log.d("Save", "writeListToFile  call error");

            }

    }

   

    public void Disp_Data(){

      Log.d("Disp_Data()", "Disp_Data() Calling--->");

      String CurData="";

      for (int i=0; i < ListMaps.size();i++){

            HashMap<String, String> map=ListMaps.get(i);

            CurData =CurData+map.get("Name")+"\n";

      }

     

      dip_tv.setText(CurData);     

    }

   

           

    public void load_data(){

      if(loadListFromFile((ArrayList<HashMap<String, String>>) ListMaps) !=

            null){

            ListMaps = loadListFromFile((ArrayList<HashMap<String, String>>)

                        ListMaps);

      }

     

      Disp_Data();

    }

   

    public void File_Read_Write(int type){

      if (type==READ){

           

      }else if (type==WRITE){

           

      }

    }

   

    private void writeListToFile(ArrayList<HashMap<String, String>> masterlistrev){

      if(null == FileName)

          throw new RuntimeException ("FileName is null!");

        File myfile = getFileStreamPath(FileName);

        try {

            if(myfile.exists() || myfile.createNewFile()){

                FileOutputStream fos = openFileOutput(FileName, MODE_PRIVATE);

                ObjectOutputStream oos = new ObjectOutputStream(fos);

                oos.writeObject(masterlistrev);

                fos.close();

            }

        } catch (Exception e) {

         e.printStackTrace();

        }

     }

    private ArrayList<HashMap<String, String>> loadListFromFile(

         ArrayList<HashMap<String, String>> masterlistrev) {

      if(null == FileName)

          return null;

     

      File myfile = getFileStreamPath(FileName);

      try {

            if(myfile.exists()){

                  FileInputStream fis = openFileInput(FileName);

                  ObjectInputStream ois = new ObjectInputStream(fis);

                  masterlistrev = (ArrayList<HashMap<String, String>>) ois.readObject();

                  fis.close();

            }else {

                  return null;

            }

       } catch (Exception e) {

          e.printStackTrace();

       }

       return masterlistrev;

      }

   

    private OnClickListener ButtonClickL= new OnClickListener() {

      public void onClick(View v) {

            if(v==add_b){

                  Add_Data();

            }else if(v== save_b){

                  Save_Data();

            }

      }

    };

}