android获取网络图片

注意点：
1在清单文件中添加android.permission.INTERNET权限 
2网络请求需要在新的线程中进行
3将获取到的图片塞进imageview需要在主线程中进行

public class MainActivity extends Activity implements OnClickListener{

Button get;

TextView tv;

ImageView iv;

final static int IMAGE = 0;

String urlStr = "http://img.qzone.la/uploads/allimg/110629/co110629135Z1-6.jpg";

Handler handler = new Handler(){

public void handleMessage(android.os.Message msg) {

 switch (msg.what) {

case IMAGE:

Bitmap bitmap = (Bitmap) msg.obj;

iv.setImageBitmap(bitmap);

break;

}

};

};

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

get = (Button) findViewById(R.id.get);

get.setOnClickListener(this);

tv = (TextView) findViewById(R.id.tv);

iv = (ImageView)findViewById(R.id.iv); 

tv.setText(urlStr);

}

@Override

public void onClick(View v) {

switch (v.getId()) {

case R.id.get:

new Thread(new Runnable() {

@Override

public void run() {

getImage();

}

}).start();

break;

}

}

public void getImage(){

try {

URL url = new URL(urlStr);

HttpURLConnection conn =  (HttpURLConnection) url.openConnection();

conn.setRequestMethod("GET");

conn.setReadTimeout(5*1000);

conn.connect();

InputStream inputStream = conn.getInputStream();//通过输入流获得图片数据

byte[] data = readInputStream(inputStream);

Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);

Message msg = new Message();

msg.what = IMAGE;

msg.obj = bitmap;

handler.sendMessage(msg);

} catch (MalformedURLException e) {

e.printStackTrace();

} catch (Throwable e) {

e.printStackTrace();

}

}

public  byte[] readInputStream(InputStream inputStream) throws IOException {  

        byte[] buffer = new byte[1024];  

        int len = 0;  

        ByteArrayOutputStream bos = new ByteArrayOutputStream();  

        while((len = inputStream.read(buffer)) != -1) {  

            bos.write(buffer, 0, len);  

        }  

        bos.close();  

        return bos.toByteArray();  

    }  

}