How to get file extension using java code

To get extension, we can use the following java code:

int dotposition= file.lastIndexOf(".");
filename_Without_Ext = file.substring(0,dotposition);
ext = file.substring(dotposition + 1, file.length());

Modify last exercise "More for Pick a file using Intent.ACTION_GET_CONTENT", a new class filename is implemented to get file extention and filename without extention.



main.xml

<?xml version="1.0" encoding="utf-8"?>
<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:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:text="@string/hello"
  />
<Button
  android:id="@+id/buttonpick"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:text="- PICK a file -"
  />
<TextView
  android:id="@+id/textfile"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  />
<TextView
  android:id="@+id/textfolder"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  />
<TextView
  android:id="@+id/textfilename"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  />
<TextView
  android:id="@+id/textfilename_withoutext"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  />
<TextView
  android:id="@+id/textfilename_ext"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  />
</LinearLayout>

main code

package com.exercise.AndroidPick_a_File;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class AndroidPick_a_File extends Activity {

TextView textFile, textFileName, textFolder;
TextView textFileName_WithoutExt, textFileName_Ext;

private static final int PICKFILE_RESULT_CODE = 1;

  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
    
      Button buttonPick = (Button)findViewById(R.id.buttonpick);
      textFile = (TextView)findViewById(R.id.textfile);
      textFolder = (TextView)findViewById(R.id.textfolder);
      textFileName = (TextView)findViewById(R.id.textfilename);
    
      textFileName_WithoutExt = (TextView)findViewById(R.id.textfilename_withoutext);
      textFileName_Ext = (TextView)findViewById(R.id.textfilename_ext);
    
      buttonPick.setOnClickListener(new Button.OnClickListener(){

  @Override
  public void onClick(View arg0) {
   // TODO Auto-generated method stub

   Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
            intent.setType("file/*");
      startActivityForResult(intent,PICKFILE_RESULT_CODE);
  
  }});
  }

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
 // TODO Auto-generated method stub
 switch(requestCode){
 case PICKFILE_RESULT_CODE:
  if(resultCode==RESULT_OK){
  
   String FilePath = data.getData().getPath();
   String FileName = data.getData().getLastPathSegment();
   int lastPos = FilePath.length() - FileName.length();
   String Folder = FilePath.substring(0, lastPos);
  
   textFile.setText("Full Path: \n" + FilePath + "\n");
   textFolder.setText("Folder: \n" + Folder + "\n");
   textFileName.setText("File Name: \n" + FileName + "\n");
  
   filename thisFile = new filename(FileName);
   textFileName_WithoutExt.setText("Filename without Ext: " + thisFile.getFilename_Without_Ext());
         textFileName_Ext.setText("Ext: " + thisFile.getExt());
  
  }
  break;
 
 }
}

private class filename{

 String filename_Without_Ext = "";
 String ext = "";

 filename(String file){
     int dotposition= file.lastIndexOf(".");
     filename_Without_Ext = file.substring(0,dotposition);
     ext = file.substring(dotposition + 1, file.length());
 }

 String getFilename_Without_Ext(){
  return filename_Without_Ext;
 }

 String getExt(){
  return ext;
 }
}

}

Download the files.

Related:
- Unzip compressed file, using java.util.zip