CodeShowSDCard

package com.example.hhh;

import java.io.File;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final File folder = new File("/sdcard");
        listFilesForFolder(folder);

    }

    public void listFilesForFolder(final File folder) {
        for (final File fileEntry : folder.listFiles()) {
            if (fileEntry.isDirectory()) {
                listFilesForFolder(fileEntry);
            } else {
                if (fileEntry.getName().endsWith(".png")
                        || fileEntry.getName().endsWith(".jpg")
                        || fileEntry.getName().endsWith(".jpeg")
                        || fileEntry.getName().endsWith(".gif")) {
                    System.out.println(fileEntry.getPath());
                }
            }
        }
    }

}