android=》下载图片

public class C6Demo01_DownImageActivity extends Activity {
    /** Called when the activity is first created. */
private Button btn;
private ImageView iv;
private URL url;
private InputStream input;
private FileOutputStream output;
private File path;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        btn=(Button) findViewById(R.id.btn);
        iv=(ImageView) findViewById(R.id.iv);
        btn.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
try {
url=new URL("http://wenwen.soso.com/p/20110724/20110724161153-1243191028.jpg");
   input=url.openStream();
System.out.println("input="+input);
Bitmap bitmap=BitmapFactory.decodeStream(input);
iv.setImageBitmap(bitmap);

input.close();
// writeTosdCard();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
});
       
    }
    public void writeTosdCard(){
    path=new File(Environment.getExternalStorageDirectory()+"/images");
    if(!path.exists()){
    path.mkdirs();
    }
    File file=new File(path+"/image.jpg");
    try {
output=new FileOutputStream(file);
input=url.openStream();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
   
    byte[] buffer=new byte[1024];
    int t;
    try {
while((t=input.read(buffer))!=-1){
output.write(buffer,0,t);
input.close();
output.close();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
   
    }
    
}