我给你来个完整的，经过测试的！

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        executorService.execute(new downloadRun());
    }

    private ExecutorService executorService = Executors.newFixedThreadPool(4);
    private class downloadRun implements Runnable {
        @Override
        public void run() {
            InputStream inputStream = null;
            ByteArrayOutputStream byteArrayOutputStream = null;
            byte[] buff;
            int len;
            try {
                URL url = new URL("www.360ito.com");
                try {
                    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                    connection.setConnectTimeout(15 * 1000);
                    connection.setReadTimeout(10 * 1000);
                    connection.setRequestMethod("GET");
                    connection.setDoInput(true);
                    connection.connect();
                    byteArrayOutputStream = new ByteArrayOutputStream();
                    buff = new byte[1024];
                    
                    if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                        inputStream = connection.getInputStream();
                        while ((len = inputStream.read(buff)) != -1) {
                            byteArrayOutputStream.write(buff, 0, len);
                        }
                        byteArrayOutputStream.flush();
                    }
                    
                } catch (IOException e) {
                    e.printStackTrace();
                }
                finally {
                     if (null != inputStream) {
                         try {
                             inputStream.close();
                         } catch (IOException e) {
                             e.printStackTrace();
                         }
                     }
                     if (null != byteArrayOutputStream) {
                         try {
                             byteArrayOutputStream.close();
                         } catch (IOException e) {
                             e.printStackTrace();
                         }
                     }
                }
            } catch (MalformedURLException e) {
                e.printStackTrace();
            }
        }
    };

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        new Thread(downloadRun).start();
    }

    Runnable downloadRun = new Runnable(){

        @Override
        public void run() {
            // 在这里处理网络
        }
    };