Android网络编程之HttpURLConnection应用-快递查询案例

前言

HttpURLConnection是一种多用途、轻量极的HTTP客户端。它的API简单，体积较小，因而非常适用于Android项目，压缩和缓存机制可以有效地减少网络访问的流量，在提升速度和省电方面也起到了较大的作用，使用它来进行HTTP操作可以适用于大多数的应用程序。HttpUrlConnection是Android SDK的标准实现，直接支持系统级连接池，即打开的连接不会直接关闭，在一段时间内所有程序可共用；直接在系统层面做了缓存策略处理，加快重复请求的速度

本文将以一个查询快递信息的案例来介绍，包括GET，POST两中方式请求网络资源，解析JSON数据，Handler异步消息处理机制等应用~

部分代码

• 主界面
• 这里主要介绍GET和POST两种网络请求方式private void doGet(final String params) { //子线程执行网络操作 new Thread(new Runnable() { @Override public void run() { try { URL url = new URL(URL_Source+"?type="+URLEncoder.encode(Param_DHL,"UTF-8")+"&postid="+URLEncoder.encode(params,"UTF-8")); HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection(); httpURLConnection.setRequestMethod("GET");//设置请求方式为GET httpURLConnection.setReadTimeout(3000);//设置连接超时时间 if(httpURLConnection.getResponseCode() == 200){ InputStream is = httpURLConnection.getInputStream(); BufferedReader br = new BufferedReader(new InputStreamReader(is)); String line =""; StringBuffer result= new StringBuffer(); while((line = br.readLine()) != null){ result.append(line); } is.close(); br.close(); httpURLConnection.disconnect();//关闭连接 Message message =new Message();//创建消息体 message.what = 1; message.obj = parseData(result.toString()); handler.sendMessage(message);//发送消息体，添加到消息队列中 } } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } }).start(); }

private void doPost(final String params) {
       new Thread(new Runnable() {
           @Override
           public void run() {
               try {
                   URL url = new URL(URL_Source);
                   HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                   httpURLConnection.setConnectTimeout(3000);     //设置连接超时时间
                   httpURLConnection.setDoInput(true);            //打开输入流，以便从服务器获取数据
                   httpURLConnection.setDoOutput(true);           //打开输出流，以便向服务器提交数据
                   httpURLConnection.setUseCaches(false);         //禁用缓存
                   httpURLConnection.setRequestMethod("POST");
                   httpURLConnection.setRequestProperty("Content-Type","application/x-www-form-urlencoded");//设置数据编码方式
                   String param ="type="+URLEncoder.encode(Param_DHL,"UTF-8") +"&postid="+URLEncoder.encode(params,"UTF-8");

                   OutputStream os = httpURLConnection.getOutputStream();
                   os.write(param.getBytes());

                   if(httpURLConnection.getResponseCode() == 200){
                       InputStream is = httpURLConnection.getInputStream();
                       BufferedReader br = new BufferedReader(new InputStreamReader(is));
                       String line ="";
                       StringBuffer result= new StringBuffer();
                       while((line = br.readLine()) != null){
                           result.append(line);
                       }
                       is.close();
                       br.close();

                       httpURLConnection.disconnect();//关闭连接
                       Message message =new Message();
                       message.what = 2;
                       message.obj = parseData(result.toString());
                       handler.sendMessage(message);

                   }
               } catch (MalformedURLException e) {
                   e.printStackTrace();
               } catch (IOException e) {
                   e.printStackTrace();
               }


           }
       }).start();
   }

• JSON数据的解析 private String parseData(String json){ String result = ""; try { JSONObject jsonObject = new JSONObject(json); JSONArray data = jsonObject.getJSONArray("data"); //这里只取最新的一条数据显示 if(data.length()>0){ result="更新时间: "+data.getJSONObject(0).getString("time")+ "\n状态: "+data.getJSONObject(0).getString("context"); }else{ result = "该单号暂无物流进展,请稍后再试,或检查公司和单号是否有误"; } } catch (JSONException e) { e.printStackTrace(); } return result; }
• 使用Handler更新UI

private Handler handler = new Handler(){
    @Override
    public void handleMessage(Message msg) {
       if(msg.what == 1){
           message.setText("最新状态 (GET方式)");
           info.setText(msg.obj+"");
       }else if (msg.what == 2){
           message.setText("最新状态 (POST方式)");
           info.setText(msg.obj+"");
       }
    }
};

项目源码

等待上传中~