Create a simple File Explorer in Android

Many android apps need a File browser to help users work with files in their device. In this tutorial we going to create a simple File Explorer.

Here is a result of this tutorial:

This project is developed in Eclipse 4.2.0.

1. Make application interface: The main layout of this app demo is very simple layout. It have one text view, one edit text and one button.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:orientation="vertical"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    >

    <TextView android:id="@+id/textview"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="Get File Name From SDCard" 

        android:textSize="18dp"

        android:gravity="center"

        android:layout_marginTop="10dp"     

    />   

    <RelativeLayout android:id="@+id/relativeLayout1"

        android:layout_height="wrap_content"

        android:layout_width="wrap_content"> 

        <EditText

            android:layout_alignParentLeft="true"

            android:hint="EditText"

            android:id="@+id/editText"

            android:layout_width="fill_parent"

            android:layout_height="wrap_content"

            android:layout_marginLeft="5dp"

            android:layout_marginRight="5dp"

            android:layout_marginTop="15dp"

            android:ems="10"

            android:inputType="textPersonName"

            android:layout_toLeftOf="@+id/skipButton">

        </EditText>

   

        <Button android:text="Browser"

                 android:id="@+id/skipButton"

                 android:textSize="18dp"

                 android:layout_marginTop="10dp"

                 android:layout_alignParentRight="true"

                 android:layout_height="wrap_content"

                 android:layout_width="wrap_content"

                 android:onClick="getfile">

         </Button>

    </RelativeLayout>

</LinearLayout>

We show all items(folder and file) on File-explorer under a custom list view and here is the code xml layout for each row in list:

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout

  xmlns:android="http://schemas.android.com/apk/res/android"

  android:layout_height="wrap_content" android:orientation="vertical" android:layout_width="fill_parent">

<ImageView

    android:id="@+id/fd_Icon1"

    android:layout_width="50dip"

    android:layout_height="50dip" >

</ImageView>

               

<TextView android:text="@+id/TextView01"

    android:id="@+id/TextView01"

    android:layout_width="wrap_content"

    android:layout_height="wrap_content"

    android:singleLine="true"

    android:textStyle="bold"

    android:layout_toRightOf="@+id/fd_Icon1"

    android:layout_marginTop="5dip" 

    android:layout_marginLeft="5dip">

</TextView>

<TextView android:text="@+id/TextView02"

    android:id="@+id/TextView02"

    android:layout_width="wrap_content"

    android:layout_height="wrap_content"

    android:layout_toRightOf="@+id/fd_Icon1"

    android:layout_below="@+id/TextView01"

    android:layout_marginLeft="10dip">

   

</TextView>

<TextView android:text="@+id/TextViewDate"

    android:id="@+id/TextViewDate"

    android:layout_width="wrap_content"

    android:layout_height="wrap_content"

    android:layout_below="@+id/TextView01"

    android:layout_alignParentRight="true"

    android:layout_marginLeft="5dip">

</TextView>

</RelativeLayout>

Each row have three text views, the first one shows the name of item, the second text view shows the number of item if that row contains a folder and show the capacity if it is a file, the last one shows the last modifying date of this item. The result is:

2. Java Code

2.1. Code for Main Activity, when we click on the button, we will open a new activity:

package com.example.fileexplorer;

 

import android.os.Bundle;

import android.app.Activity;

import android.content.Intent;

import android.view.View;

import android.widget.EditText;

public class FileexplorerActivity extends Activity {

        private static final int REQUEST_PATH = 1;

        String curFileName;    

        EditText edittext;

        @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_fileexplorer);

        edittext = (EditText)findViewById(R.id.editText);

    }

    public void getfile(View view){

        Intent intent1 = new Intent(this, FileChooser.class);

        startActivityForResult(intent1,REQUEST_PATH);

    }

 // Listen for results.

    protected void onActivityResult(int requestCode, int resultCode, Intent data){

        // See which child activity is calling us back.

        if (requestCode == REQUEST_PATH){

                if (resultCode == RESULT_OK) {

                        curFileName = data.getStringExtra("GetFileName");

                        edittext.setText(curFileName);

                }

         }

    }

}

The result from FileChoose is a name of file.

2.2. The new activity is FileChoose extends ListActivity, here is all codes of FileChoose Activity:

package com.example.fileexplorer;

import java.io.File;

import java.sql.Date;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import java.text.DateFormat;

import android.os.Bundle;

import android.app.ListActivity;

import android.content.Intent;

import android.view.View;

import android.widget.ListView;

public class FileChooser extends ListActivity {

    private File currentDir;

    privateFileArrayAdapter adapter;

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        currentDir = new File("/sdcard/");

        fill(currentDir);

    }

    private void fill(File f)

    {

        File[]dirs = f.listFiles();

                 this.setTitle("Current Dir: "+f.getName());

                 List<Item>dir = new ArrayList<Item>();

                 List<Item>fls = new ArrayList<Item>();

                 try{

                         for(File ff: dirs)

                         {

                                Date lastModDate = new Date(ff.lastModified());

                                DateFormat formater = DateFormat.getDateTimeInstance();

                                String date_modify = formater.format(lastModDate);

                                if(ff.isDirectory()){

                                       

                                       

                                        File[] fbuf = ff.listFiles();

                                        int buf = 0;

                                        if(fbuf != null){

                                                buf = fbuf.length;

                                        }

                                        else buf = 0;

                                        String num_item = String.valueOf(buf);

                                        if(buf == 0) num_item = num_item + " item";

                                        else num_item = num_item + " items";

                                       

                                        //String formated = lastModDate.toString();

                                        dir.add(newItem(ff.getName(),num_item,date_modify,ff.getAbsolutePath(),"directory_icon"));

                                }

                                else

                                {

                                        fls.add(new Item(ff.getName(),ff.length() + " Byte", date_modify, ff.getAbsolutePath(),"file_icon"));

                                }

                         }

                 }catch(Exception e)

                 {   

                         

                 }

                 Collections.sort(dir);

                 Collections.sort(fls);

                 dir.addAll(fls);

                 if(!f.getName().equalsIgnoreCase("sdcard"))

                         dir.add(0,new Item("..","Parent Directory","",f.getParent(),"directory_up"));

                 adapter = new FileArrayAdapter(FileChooser.this,R.layout.file_view,dir);

                 this.setListAdapter(adapter);

    }

    @Override

        protected void onListItemClick(ListView l, View v, int position, long id) {

                // TODO Auto-generated method stub

                super.onListItemClick(l, v, position, id);

                Item o = adapter.getItem(position);

                if(o.getImage().equalsIgnoreCase("directory_icon")||o.getImage().equalsIgnoreCase("directory_up")){

                                currentDir = new File(o.getPath());

                                fill(currentDir);

                }

                else

                {

                        onFileClick(o);

                }

        }

    private void onFileClick(Item o)

    {

        //Toast.makeText(this, "Folder Clicked: "+ currentDir, Toast.LENGTH_SHORT).show();

        Intent intent = new Intent();

        intent.putExtra("GetPath",currentDir.toString());

        intent.putExtra("GetFileName",o.getName());

        setResult(RESULT_OK, intent);

        finish();

    }

}

2.3. Create FileArrayAdapter for Listview above:

package com.example.fileexplorer;

import java.util.List; 

import android.content.Context;

import android.graphics.drawable.Drawable;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.ArrayAdapter;

import android.widget.ImageView;

import android.widget.TextView;

public class FileArrayAdapter extends ArrayAdapter<Item>{

        private Context c;

        private int id;

        private List<Item>items;

       

        public FileArrayAdapter(Context context, int textViewResourceId,

                        List<Item> objects) {

                super(context, textViewResourceId, objects);

                c = context;

                id = textViewResourceId;

                items = objects;

        }

        public Item getItem(int i)

         {

                 return items.get(i);

         }

         @Override

       public View getView(int position, View convertView, ViewGroup parent) {

               View v = convertView;

               if (v == null) {

                   LayoutInflater vi = (LayoutInflater)c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

                   v = vi.inflate(id, null);

               }

              

               /* create a new view of my layout and inflate it in the row */

                //convertView = ( RelativeLayout ) inflater.inflate( resource, null );

               

               final Item o = items.get(position);

               if (o != null) {

                       TextView t1 = (TextView) v.findViewById(R.id.TextView01);

                       TextView t2 = (TextView) v.findViewById(R.id.TextView02);

                       TextView t3 = (TextView) v.findViewById(R.id.TextViewDate);

                       /* Take the ImageView from layout and set the city's image */

                                ImageView imageCity = (ImageView) v.findViewById(R.id.fd_Icon1);

                                String uri = "drawable/" + o.getImage();

                           int imageResource = c.getResources().getIdentifier(uri, null, c.getPackageName());

                           Drawable image = c.getResources().getDrawable(imageResource);

                           imageCity.setImageDrawable(image);

                      

                       if(t1!=null)

                       t1.setText(o.getName());

                       if(t2!=null)

                                t2.setText(o.getData());

                       if(t3!=null)

                                t3.setText(o.getDate());

               }

               return v;

       }

}

2.4. Finally we create file item.java for item object:

package com.example.fileexplorer;

public class Item implements Comparable<Item>{

        private String name;

        private String data;

        private String date;

        private String path;

        private String image;

       

        public Item(String n,String d, String dt, String p, String img)

        {

                name = n;

                data = d;

                date = dt;

                path = p;

                image = img;           

        }

        public String getName()

        {

                return name;

        }

        public String getData()

        {

                return data;

        }

        public String getDate()

        {

                return date;

        }

        public String getPath()

        {

                return path;

        }

        public String getImage() {

                return image;

        }

        public int compareTo(Item o) {

                if(this.name != null)

                        return this.name.toLowerCase().compareTo(o.getName().toLowerCase());

                else

                        throw new IllegalArgumentException();

        }

}

3.DEMO

3.1. Run application

3.2. Click on a button

3.3. After click on a file in File-explorer, show this file name on edit text on Main activity

You can download all source codes of this tutorial from here.  

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