If you have to download images & save in SDcard.Kindly follow below code:
package com.tablet;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;
import java.net.UnknownHostException;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
/*
 * This class download & store the media in external storage 
 * */
public class DownloadActivity extends Activity {
    private static String fileName = "android.jgp";
    private Button btnDownload;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        btnDownload = (Button) findViewById(R.id.download);
        btnDownload.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                // TODO Auto-generated method stub
                download();
            }
        });
    private void download()
    {
        System.out.println("Inside Download");
        try {
            // this is the file you want to download from the remote server
            String path = "http://code.google.com/android/goodies/wallpaper/android-wallpaper5_1024x768.jpg";
            URL u = new URL(path);
            HttpURLConnection c = (HttpURLConnection) u.openConnection();
            c.setRequestMethod("GET");
            c.setDoOutput(true);
            c.connect();
            String PATH = "/data/Kamal"
                //Environment.getExternalStorageDirectory()
            // + "/download/";
                    + "/";
            Log.v("log_tag", "PATH: " + PATH);
            File file = new File(PATH);
            file.mkdirs();
            File outputFile = new File(file, fileName);
            FileOutputStream f = new FileOutputStream(outputFile);
            InputStream in = c.getInputStream();
            Log.v("log_tag"," InputStream consist of : "+in.read());
            byte[] buffer = new byte[1024];
            int len1 = 0;
            while ((len1 = in.read(buffer)) > 0) {
                //System.out.println("Reading byte : "+in.read(buffer));
                f.write(buffer, 0, len1);
            }
            Toast.makeText(this, "Download Completed Successfully @ "+PATH, Toast.LENGTH_LONG).show();
            f.close();
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            Toast.makeText(this, "MalformedURLException", Toast.LENGTH_LONG).show();
        } catch (ProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            Toast.makeText(this, "ProtocolException", Toast.LENGTH_LONG).show();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            Toast.makeText(this, "FileNotFoundException", Toast.LENGTH_LONG).show();
        }catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            Toast.makeText(this, "UnknownHostException", Toast.LENGTH_LONG).show();
        }
        catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            Toast.makeText(this, "IOException", Toast.LENGTH_LONG).show();
        }
    }
}