如何加载JSP页面并同时在json文件上写入数据？

Question

Could someone give me an example of a JSP page which will contain an array variable with some data and every time when the JSP page will be loaded, those data in the array will be written in a json file in a specific directory. Then I will process with the data in the json file using another html page.

Later, I would make a connection with my DB to the JSP page. But, firstly i have to handle it without any database. So, the idea is when my DB will be updated; JSP page will automatically update the json file (As per my expected scenario) and with every load of the JSP page (or clicking some button), I could process with different set of data every time.

I am little bit confused though.. this kind of scenario is possible or not?

And, I also tried some codes like:-

<%-- Set the content type header with the JSP directive --%>
<%@ page contentType="application/json" %>

<%-- Set the content disposition header --%>
<%
// Returns all employees (active and terminated) as json.
response.setContentType("application/json");
response.setHeader("Content-Disposition", "inline");
%>

<%@ page language="java"%>
<%@ page import="java.sql.*"%>
<%@ page import="java.util.*"%>
<%@ page import="java.text.*"%>
<%@ page import="javax.servlet.http.*"%>


[
{"label":"item 1", "value":"item 1", "id": 1},
{"label":"item 2", "value":"item 2", "id": 2},
{"label":"item 3", "value":"item 1", "id": 3}
]

But, I couldn't able to write data in a json file through any of these codes rather it shows data on the page.

Could someone give me any idea that how can I implement the scenario??

Answer 1

I have solved the problem .

Suppose you want to write some column values in a jsp page. Simply use... json.dumps() and json.load function.

Here's the exapmple

 import json data = { 'name' : 'ACME', 'shares' : 100, 'price' : 542.23 } json_str = json.dumps(data) data = json.loads(json_str) # Writing JSON data with open('data.json', 'w') as f: json.dump(data, f) # Reading data back with open('data.json', 'r') as f: data = json.load(f)