从网上读取图片在本地显示

package df.util;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.widget.Button;
import android.widget.ImageView;
import com.aspire.demo.R;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

/**
* Created with IntelliJ IDEA.
* User: pdh
* Date: 13-4-26
* Time: 下午11:46
* To change this template use File | Settings | File Templates.
*/

public class ActivityMain extends Activity {
/** Called when the activity is first created. */
String imageUrl = "http://www.huway.com/d/file/2011/03/02/689803e7955dd20ab84d91ed409761d3.jpg";
Bitmap bmImg;
ImageView imView;

Button button1;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.goimg);
imView = (ImageView) findViewById(R.id.imview);
imView.setImageBitmap(returnBitMap(imageUrl));

}

public Bitmap returnBitMap(String url) {
URL myFileUrl = null;
Bitmap bitmap = null;
try {
myFileUrl = new URL(url);
} catch (MalformedURLException e) {
e.printStackTrace();
}
try {
HttpURLConnection conn = (HttpURLConnection) myFileUrl
.openConnection();
conn.setDoInput(true);
conn.connect();
InputStream is = conn.getInputStream();
bitmap = BitmapFactory.decodeStream(is);
is.close();
} catch (IOException e) {
e.printStackTrace();
}
return bitmap;
}

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ImageView android:id="@+id/imview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"/>
</LinearLayout>

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