尝试在安卓浏览器里面访问这个api

经测试，在Android中也可以正常获取到数据。

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        new Thread(){
            @Override
            public void run() {
                // TODO Auto-generated method stub
                String httpUrl = "http://apis.baidu.com/heweather/weather/free";
                String httpArg = "city=beijing";
                BufferedReader reader = null;
                String result = null;
                StringBuffer sbf = new StringBuffer();
                httpUrl = httpUrl + "?" + httpArg;

                try {
                    URL url = new URL(httpUrl);
                    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setRequestProperty("apikey","f1375c3a44007cdc331966524783f3ab");
                    connection.connect();
                    InputStream is = connection.getInputStream();
                    reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
                    String strRead = null;
                    while ((strRead = reader.readLine()) != null) {
                        sbf.append(strRead);
                        sbf.append("\r\n");
                    }
                    reader.close();
                    result = sbf.toString();
                } catch (Exception e) {
                    e.printStackTrace();
                }
                Log.d("tag",result+"-------");            
                super.run();
            }            
        }.start();

    }

Android中获取网络数据需要新开线程，另外还需要在Manifest中添加权限。