Ajax in Java JSP Servlet based web applications are very common. Recently I have written a lot about jQuery methods and how we can use them. Today we will look into one of the important jQuery functionality where we can easily execute AJAX calls and process the response in a Java Servlet JSP based web application.
I am using Eclipse IDE for creating the “Dynamic Web Project”, you can use any other IDE too. Our main focus will be towards jQuery and AJAX call from JSP to a servlet. Below image shows the final project structure.
We have a very simple servlet that gets the userName from request, create a greetings and return it as plain text.
package com.journaldev.servlets;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/GetUserServlet")
public class GetUserServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String userName = request.getParameter("userName").trim();
if(userName == null || "".equals(userName)){
userName = "Guest";
}
String greetings = "Hello " + userName;
response.setContentType("text/plain");
response.getWriter().write(greetings);
}
}
Notice that I am using Servlet-3 annotations for configuration, if you like XML based configuration then you can do it in web.xml file. We will call this servlet asynchronously using jQuery AJAX support.
Below is our JSP page code, it has an input field where we can provide user name. As soon as focus is moved out of it, jQuery AJAX method will execute and call our servlet and process the response. index.jsp code:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"https://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>jQuery, Ajax and Servlet/JSP integration example</title>
<script src="https://code.jquery.com/jquery-1.10.2.js"
type="text/javascript"></script>
<script src="js/app-ajax.js" type="text/javascript"></script>
</head>
<body>
<form>
Enter Your Name: <input type="text" id="userName" />
</form>
<br>
<br>
<strong>Ajax Response</strong>:
<div id="ajaxGetUserServletResponse"></div>
</body>
</html>
Notice that we have two JS files included in the JSP page, first one is the jQuery JS library and another one contains our JS code for ajax call. I am including jQuery JS from the code.jquery.com URL, we can also download it and keep with our JS file. JSP code is very simple, we will populate ajaxGetUserServletResponse
div content from the AJAX call response through jQuery.
Below is our javascript file code for jQuery AJAX request. app-ajax.js code:
$(document).ready(function() {
$('#userName').blur(function(event) {
var name = $('#userName').val();
$.get('GetUserServlet', {
userName : name
}, function(responseText) {
$('#ajaxGetUserServletResponse').text(responseText);
});
});
});
We can also make jQuery AJAX call using it’s ajax() method, as shown below. Above is the shorthand approach to using ajax() method.
$(document).ready(function() {
$('#userName').blur(function() {
$.ajax({
url : 'GetUserServlet',
data : {
userName : $('#userName').val()
},
success : function(responseText) {
$('#ajaxGetUserServletResponse').text(responseText);
}
});
});
});
Below is the syntax of the jQuery ajax() method, try to relate it to the above code and you will understand what’s going on here.
$.ajax({
url: url,
data: data,
success: success,
dataType: dataType
});
Our jQuery Ajax JSP Servlet Example application is ready, just build and deploy it in your favorite servlet container. Below image shows the output produced, I am using Chrome Developer tools to confirm that our servlet is getting called.
We learned the basics of jQuery AJAX support and how we can integrate it with Java web application, in next tutorials we will learn more features of jQuery that we can use in any web application. You can download the final project from the below link.
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if i have multiple value then what should i do in java controller please tell me
- hemant
I got this example working easily. Thank you very much. Some specifics about my experience: 1) I am using eclipse and tomcat. 2) To make your servlet, I right-clicked in eclipse on my project in the project explorer and chose “new - > servlet” and then used your convenient copy button to help copy-paste your servlet code into my new servlet source file. 3) I was nervous about using your code.jquery.com version of jquery since it is http and not https, but fortunately I didn’t need to use it, since my code already referred to cdnjs.cloudflare.com which is https. /Eric Osman 4-dec-2019 Feel free to reach me here: eric osman at rcn dot com
- Eric Osman
Hi, i have a request kindly tell me can i call a .net service through this ajax call, if yes then how.
- sivani sahoo
Thanks it will helpful for me
- Balakrishna
I’m trying to import your example. Usage Spring sts 3.9.6 Release. I am new to the environment and I would like to learn from your examples, but importing it as a maven project gives me a considerable number of errors. how can I do my mail is misonsan@libero.it I’m Italian and my name is Moreno
- Moreno
Hey buddy, Thank you so much for this code. You have saved my life. Last one week i was working on this ajax code but i didnt getting it.And finally i got it. Thanks again.
- Kunal bhide
Not working for me . You may be missed to write regarding web.xml
- gyana
Hello , This Example is working fine… Thanks…
- shahjad
Dear Pankaj, Thank for this program. I am not getting the desired output …when i enter the name “Guest” …I am not getting “Hello Guest” as an Ajax response. Build successfully(clean and install all). Kindly reply. thank you. Regards,
- Sidharth
There is not servlet class file in the example.There is source file but not class file.That’s why so many people were unable to run it.Actually he has correctly not compiled the file as the java versions of people would differ and they would not be able to run it.So first compile the servlet file to class file and then place it in the classes forlder and it would work
- Ath J