调用接口,无非也就是打开链接 读取流 将结果以流的形式输出
将查询结果以json返回，无非就是将查询到的结果转换成jsonObject
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/***
* 将从数据中取到的结果以json的格式返回
*
* @param response
* @throws IOException
*/
@RequestMapping(value = "/getJson")
public void getJson(HttpServletResponse response) throws IOException {
List list = userService.getUsers();
JSONArray Js = JSONArray.fromObject(list);
JSONObject jsonObject = new JSONObject();
jsonObject.put("msg", "success");
jsonObject.put("data", Js.toString());
ServletOutputStream out = response.getOutputStream();
out.print(jsonObject.toString());
}
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/***
* 调用接口
* @param mm
* @param response
* @return
* @throws IOException
*/
@RequestMapping(value = "/getUser")
public String getUsers(ModelMap mm, HttpServletResponse response)
throws IOException {
String url = "http://127.0.0.1:8080/ssm/getJson";
URL postUrl = new URL(url);
HttpURLConnection connection = (HttpURLConnection) postUrl.openConnection();
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setRequestMethod("POST");
connection.setUseCaches(false);
connection.setInstanceFollowRedirects(true);
connection.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
Map<String,String> headerMap=new HashMap<String,String>();
if(!headerMap.isEmpty()){
for (Map.Entry<String, String> entry : headerMap.entrySet()) {
connection.setRequestProperty(entry.getKey(),entry.getValue());
}
}
connection.connect();
DataOutputStream out = new DataOutputStream(connection.getOutputStream());
//out.writeBytes(content);//content为方法参数
out.flush();
out.close(); // flush and close
BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream(), "utf-8"));
String line="";
line = reader.readLine();
reader.close();
connection.disconnect();
mm.addAttribute("line", line);
//mm.addAttribute("list", userService.getUsers());
return "index.jsp";
}