Can't check if file on sdcard exists

Question

I'm trying to make a simple check if the file exist. I saw similar questions here, but they didn't help. When I run my application, the app crashes and I got message "Unfortunatelly, fileCheck1 has stopped". I got this error both on emulator and smartphone.

My code:

package com.example.fileCheck1;

import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.widget.TextView;

import java.io.File;

public class MyActivity extends Activity {

    TextView msgText;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        msgText = (TextView) findViewById(R.id.textView);
        String Path = Environment.getExternalStorageDirectory().getPath()+"/ping.xml";
        File file = getBaseContext().getFileStreamPath(Path);
        if(file.exists()){
            msgText.setText("Found");
        }
        if(!file.exists()){
            msgText.setText("Not Found");
        }
    }
}

In my Manifest such permissions:

<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>

Thanks in advance.

Answer 1

I think that problem is here:

getBaseContext()

where it is assigned to NULL. You really don't need this line. You can simply achieve your goal with

String path = Environment.getExternalStorageDirectory().getPath() + "/ping.xml";
File f = new File(path);
if (f.exists()) {
   // do your stuff
}
else {
  // do your stuff
}

Update:

If you or someone else have Samsung Galaxy S3, please follow @Raghunandan's answer because in this case getExternalStorageDirectory() returns internal memory.

Answer 2

I have samsung galaxy s3 with android 4.1.2. My internal phone memory is named sdcard0 and my external card extSdCard.

Environment.getExternalStorageDirectory()

So the above returns the path of sdcard0 which is internal phone memory

So get the actual path you can use the below

String externalpath = new String();
String internalpath = new String();

public  void getExternalMounts() {
Runtime runtime = Runtime.getRuntime();
try
{
Process proc = runtime.exec("mount");
InputStream is = proc.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
String line;

BufferedReader br = new BufferedReader(isr);
while ((line = br.readLine()) != null) {
    if (line.contains("secure")) continue;
    if (line.contains("asec")) continue;

    if (line.contains("fat")) {//external card
        String columns[] = line.split(" ");
        if (columns != null && columns.length > 1) {
            externalpath = externalpath.concat("*" + columns[1] + "\n");
        }
} 
        else if (line.contains("fuse")) {//internal storage
        String columns[] = line.split(" ");
        if (columns != null && columns.length > 1) {
            internalpath = internalpath.concat(columns[1] + "\n");
        }
    }
}
}
catch(Exception e)
{
    e.printStackTrace();
}
  System.out.println("Path  of sd card external............"+externalpath);
  System.out.println("Path  of internal memory............"+internalpath);
}

Once you get the path

    File file = new File(internalpath+"/ping.xml");// internalpath or external path
    if(file.exists()){
        msgText.setText("Found");
    }
    else{
        msgText.setText("Not Found");
    }

UPDATE :

The above solution is not recommended. May not work well. Environment.getExternalStorageDirectory() will always return the path of External Storage. In most cases it is a Sdcard.

From the docs

public static File getExternalStorageDirectory ()

Added in API level 1 Return the primary external storage directory. This directory may not currently be accessible if it has been mounted by the user on their computer, has been removed from the device, or some other problem has happened. You can determine its current state with getExternalStorageState().

Note: don't be confused by the word "external" here. This directory can better be thought as media/shared storage. It is a filesystem that can hold a relatively large amount of data and that is shared across all applications (does not enforce permissions). Traditionally this is an SD card, but it may also be implemented as built-in storage in a device that is distinct from the protected internal storage and can be mounted as a filesystem on a computer.

Answer 3

check this:

    File file = new File(Environment.getExternalStorageDirectory()+"/ping.xml");
    if(file.exists()){
        msgText.setText("Found");
    }
    else{
        msgText.setText("Not Found");
    }