Solved

Java Servlet to AJAX return value

Posted on 2006-11-15
6
665 Views
Last Modified: 2013-11-24
I have some JS Call that is sending 2 values to a servlet.  

 testAdd: function(a, b){
     debugAPI("testAdd: " + a + ", " + b);
     var myAjax = new Ajax.Request(
     'myServlet.do?dispatch=add&aVal=' + a + '&bVal=' + b,  
     {
        method: 'get',
        onComplete: function(response) {$F("result") = response.responseText;}
     });
   }

1.  What would the basic servlet code look like that adds these numbers?

2.  How does the servlet return the result back to the JavaScript?
0
Comment
Question by:tmonteit
  • 3
  • 2
6 Comments
 
LVL 86

Expert Comment

by:CEHJ
ID: 17947659
in doGet

out.println(Integer.parseInt(req.getParameter("a") + Integer.parseInt(req.getParameter("b"));

1. See above
2. See above
0
 

Author Comment

by:tmonteit
ID: 17947974

I want to capture the output in a JS var.

What does the JS Code look like that captures that?
0
 
LVL 13

Accepted Solution

by:
kawas earned 500 total points
ID: 17948090
var theURL = your_url_to_servlet_with_parameters;
var request = getXMLhttp(); // assuming that this gets the XMLHttpRequest object for you
request.open("GET", theURL, true);
request.onreadystatechange = function() {
    if (mc.request.readyState == 4 && mc.request.status == 200) {
          // s contains the number
          var s = mc.request.responseText;
    }
}; // end function()
request.send(null);
0
Resolve Critical IT Incidents Fast

If your data, services or processes become compromised, your organization can suffer damage in just minutes and how fast you communicate during a major IT incident is everything. Learn how to immediately identify incidents & best practices to resolve them quickly and effectively.

 
LVL 13

Expert Comment

by:kawas
ID: 17948095
should read:
if (request.readyState == 4 && request.status == 200) {
          // s contains the number
          var s = request.responseText;
}
0
 

Author Comment

by:tmonteit
ID: 17948180
I'm using the 'prototype' js library does that make a difference?

how do I integrate it into my existing js function?
0
 
LVL 13

Expert Comment

by:kawas
ID: 17948213
It does of course. you will have to see how they use ajax. most likely, its just a method call and you wont have to use the code that i wrote. The code I wrote assumed that you were writing your own javascript methods.
0

Featured Post

Webinar: Aligning, Automating, Winning

Join Dan Russo, Senior Manager of Operations Intelligence, for an in-depth discussion on how Dealertrack, leading provider of integrated digital solutions for the automotive industry, transformed their DevOps processes to increase collaboration and move with greater velocity.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Best practices for sharing large amounts of data 9 96
javap bin 2 41
MySqlDump not dumping triggers 1 43
Error in @AspectJ Based AOP with Spring 2 18
Most ColdFusion developers get confused between the CFSet, Duplicate, and Structcopy methods of copying a Structure, especially which one to use when. This Article will explain the differences in the approaches with examples; therefore, after readin…
Go is an acronym of golang, is a programming language developed Google in 2007. Go is a new language that is mostly in the C family, with significant input from Pascal/Modula/Oberon family. Hence Go arisen as low-level language with fast compilation…
Viewers learn about the scanner class in this video and are introduced to receiving user input for their programs. Additionally, objects, conditional statements, and loops are used to help reinforce the concepts. Introduce Scanner class: Importing…
The viewer will learn how to implement Singleton Design Pattern in Java.

829 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question