Android Write Text file in SD Card (Java Android)

package com.myapp;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        // editText1
        final EditText txtInput = (EditText) findViewById(R.id.editText1);
        
        // button1
        final Button btn1 = (Button) findViewById(R.id.button1);
        // Perform action on click
        btn1.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
            	
            	/*** Write Text File to SD Card ***/
					try {
						
					String path = "/mnt/sdcard/mydata/thaicreate.txt";
					File file = new File(path);
					
					/*** if exists create text file ***/
					if(!file.exists())
					{
						file.createNewFile();
					}
					
						/*** Write Text File ***/
						FileWriter writer = new FileWriter(file, true); //True = Append to file, false = Overwrite
						writer.write(txtInput.getText() + "\n");
						writer.close();
					
			 		   	Toast.makeText(MainActivity.this, "File Save!",
					 		     Toast.LENGTH_LONG).show();   
			 		   
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
			 		   Toast.makeText(MainActivity.this, "Failed! = " + e.getMessage() ,
					 		     Toast.LENGTH_LONG).show();   
				}
           

            }
        });
        

        
    }
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
	
}