Getting started with JSON and Java Web application


What is JSON?
JSON stands for JavaScript Object Notation. Its text-based open standard designed for human-readable data interchange. To know more about JSON read the wikipedia . Here is how JSON object holds the data.

{
    "firstName": "Vicky",
    "lastName": "Thakor",
    "age": 25,
    "address": {
        "streetAddress": "21 2nd Street",
        "city": "New York",
        "state": "NY",
        "postalCode": 10021
    },
    "phoneNumber": [
        {
            "type": "home",
            "number": "212 555-1234"
        },
        {
            "type": "fax",
            "number": "646 555-4567"
        }
    ]
}

Why use JSON in java web-application?
Its time to develop web-application that perform operation faster. Say if you want to process data without refreshing current page/content JSON is perfect solution for you. I'm going to show you quick demo with validating the email.

Download the JSON library for Java from sourceforge https://sourceforge.net/projects/javaqueryapi/files/


validateEmail.jsp
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Validate Email Address</title>
    </head>
    <body>
        <input name="email" id="email"/>
        <span id="result"></span>
        <input type="button" value="check" id="check"/>
        <script src="../staticCDN/js/jquery-1.8.2.min.js"></script>
        <script>
            $("#check").click(function(){
                var emailID = $("#email").val();
               $.get('emailJSON.jsp',{email:emailID},function(data){
                    var obj = eval ("(" + data + ")");
                    var status = obj.status;
                    if(status=="FAIL"){
                        alert(obj.notify_error);
                    }else{
                        //SUCCESS
                        $("#result").html("Email is Okay!");
                    }
               })
            });
        </script>
    </body>
</html>
emailJSON.jsp
<%@page import="org.json.JSONObject"%>
<%@page import="javaQuery.validation.validate"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%
String email = request.getParameter("email");
validate vEmail = new validate();
JSONObject status = new JSONObject();
if(vEmail.Email(email)){
    status.put("status", "SUCCESS");
    status.put("notify_error", "Email is Okay!");
    out.print(status);
}else{
    status.put("status", "FAIL");
    status.put("notify_error", "Provide valid email!");
    out.print(status);
}
%>

Hope you get proper idea of JSON by checking all above codes. If you have any problem let me know.
Output of Demo:
JSON

JSON

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