Http請求接口的模板

1. 使用Apache的HttpClient
   @Controller
   public class HttpDemo {

   //接口地址
   private String url = “http://ws.webxml.com.cn/webservices/qqOnlineWebService.asmx/qqCheckOnline”;

   //GET請求

  @RequestMapping("getInfo")
   @ResponseBody
   public String getInfo(){
       HttpClient httpClient = HttpClientBuilder.create().build();
       HttpGet httpGet = new HttpGet(url + "?qqCode=222222222");
       try {
           HttpResponse response = httpClient.execute(httpGet);
           HttpEntity entity = response.getEntity();
           return EntityUtils.toString(entity, "utf-8");
       } catch (IOException e) {
           e.printStackTrace();
       }
       return "";
   }

//POST請求

   @RequestMapping("postInfo")
   @ResponseBody
   public String postInfo(){
       HttpClient httpClient = HttpClientBuilder.create().build();
       List<NameValuePair> params = new ArrayList<NameValuePair>();
       params.add(new BasicNameValuePair("qqCode","222222222"));
       UrlEncodedFormEntity entity1 = null;
       try {
           entity1 = new UrlEncodedFormEntity(params, "utf-8");
       } catch (UnsupportedEncodingException e) {
           e.printStackTrace();
       }
       HttpPost httpPost = new HttpPost(url);
       httpPost.setEntity(entity1);
       httpPost.addHeader("Content-Type","application/x-www-form-urlencoded");
       HttpResponse response = null;
       try {
           response = httpClient.execute(httpPost);
       } catch (IOException e) {
           e.printStackTrace();
       }
       HttpEntity entity2 = response.getEntity();
       String ret = "";
       try {
           ret = EntityUtils.toString(entity2, "utf-8");
       } catch (IOException e) {
           e.printStackTrace();
       }
       return ret;
   }

}

2. 使用JDK自帶的HttpUrlConnection
   @Controller
   public class HttpDemo {
   //接口地址
   private String addr = “http://ws.webxml.com.cn/webservices/qqOnlineWebService.asmx/qqCheckOnline”;

   //GET請求

   @RequestMapping("getInfo")
   @ResponseBody
   public String getInfo() {
       URL url = null;
       try {
           url = new URL(addr + "?qqCode=347635191");
       } catch (MalformedURLException e) {
           e.printStackTrace();
       }
       HttpURLConnection connection = null;
       try {
           connection = (HttpURLConnection) url.openConnection();
       } catch (IOException e) {
           e.printStackTrace();
       }
       connection.setDoOutput(true);
       connection.setDoInput(true);
       try {
           connection.setRequestMethod("GET");
       } catch (ProtocolException e) {
           e.printStackTrace();
       }
       try {
           connection.connect();
       } catch (IOException e) {
           e.printStackTrace();
       }
       BufferedReader bf = null;
       try {
           bf = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
       } catch (IOException e) {
           e.printStackTrace();
       }
       String line;
       StringBuilder sb = new StringBuilder();
       try {
           while ((line = bf.readLine()) != null) {
               sb.append(line).append(System.getProperty("line.separator"));
           }
       }catch (IOException e){
           e.printStackTrace();
       }
       try {
           bf.close();
       } catch (IOException e) {
           e.printStackTrace();
       }
       connection.disconnect();
       return sb.toString();
   }
   

   //POST請求

   @RequestMapping("postInfo")
   @ResponseBody
   public String postInfo(){
       Map<String,String> param = new HashMap<String,String>();
       param.put("qqCode","347635191");
       URL url = null;
       try {
           url = new URL(addr);
       } catch (MalformedURLException e) {
           e.printStackTrace();
       }
       HttpURLConnection connection = null;
       try {
           connection = (HttpURLConnection) url.openConnection();
       } catch (IOException e) {
           e.printStackTrace();
       }
       connection.setDoOutput(true);
       connection.setDoInput(true);
       try {
           connection.setRequestMethod("POST");
       } catch (ProtocolException e) {
           e.printStackTrace();
       }
       connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=utf-8");
       try {
           connection.connect();
       } catch (IOException e) {
           e.printStackTrace();
       }
       DataOutputStream dataout = null;
       try {
           dataout = new DataOutputStream(connection.getOutputStream());
       } catch (IOException e) {
           e.printStackTrace();
       }
       String paramStr =builderUrlParams(param);
       try {
             dataout.writeBytes(paramStr);
       } catch (IOException e) {
           e.printStackTrace();
       }
       try {
           dataout.flush();
       } catch (IOException e) {
           e.printStackTrace();
       }
       try {
           dataout.close();
       } catch (IOException e) {
           e.printStackTrace();
       }
       BufferedReader bf = null;
       try {
           bf = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
       } catch (IOException e) {
           e.printStackTrace();
       }
       String line;
       StringBuilder sb = new StringBuilder();
       try {
           while ((line = bf.readLine()) != null) {
               sb.append(line).append(System.getProperty("line.separator"));
           }
       }catch (IOException e){
           e.printStackTrace();
       }
       try {
           bf.close();
       } catch (IOException e) {
           e.printStackTrace();
       }
       connection.disconnect();
       return sb.toString();
       }
   

   //構造HttpURLConnection進行Post請求所需要的參數

 public static String builderUrlParams(Map<String, String> params){
     Set<String> keySet = params.keySet();
     List<String> keyList = new ArrayList<String>(keySet);
     Collections.sort(keyList);
     StringBuilder sb = new StringBuilder();
     for (String key : keyList) {
         String value = params.get(key);
         if (StringUtils.isEmpty(value)) {
             continue;
         }
         sb.append(key);
         sb.append("=");
         try {
             sb.append(URLEncoder.encode(params.get(key),"UTF-8"));
         } catch (UnsupportedEncodingException e) {
             e.printStackTrace();
         }
         sb.append("&");
     }
     sb.deleteCharAt(sb.length() - 1);
     return sb.toString();
 }

}