How to call servlet from javascript

Question

Servlet Configuration in web.xml

<servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>DataEntry</servlet-name>
    <servlet-class>com.ctn.origin.connection.DataEntry</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>DataEntry</servlet-name>
    <url-pattern>/dataentry</url-pattern>
  </servlet-mapping>

Javascript :

<script type="text/javascript">
    function unloadEvt() {

        document.location.href='/test/dataentry';

    }
</script>

But using this javascript can't call my servlet.

Is there any error ? how to call servlet ?

did you try loading the servlet by typing the url into the browser's address bar? — Vincent Ramdhanie, Jun 02 '11 at 17:53
I'll assume that the double double quote on the end of the URL is just a careless typo. Please fix it in your question if true. — BalusC, Jun 02 '11 at 17:56
yes i am call while submit form and work perfetct. Now i want to call it onunload event of javascript — chetan, Jun 02 '11 at 18:06

BalusC · Answer 1 · 2011-06-02T18:16:35.807

From your original question:

document.location.href="/dataentry";

The leading slash / in the URL will take you to the domain root.

So if the JSP page containing the script is running on

http://localhost:8080/contextname/page.jsp

then your location URL will point to

http://localhost:8080/dataentry

But you actually need

http://localhost:8080/contextname/dataentry

So, fix the URL accordingly

document.location.href = 'dataentry';
// Or
document.location.href = '/contextname/dataentry';
// Or
document.location.href = '${pageContext.request.contextPath}/dataentry';

Apart from that, the function name unloadEvt() suggests that you're invoking the function during onunload or onbeforeunload. If this is true, then you should look for another solution. The request is not guaranteed to ever reach the server. This depends on among others the browser used. How to solve it properly depends on the sole functional requirement which is not clear from the question.

I want if user fill incomplete delete and close browser then that much detail enter into database. — chetan, Jun 02 '11 at 18:12
OK, then solve it accordingly so that you don't need to hack on the `onunload`. If you can't figure how to solve it properly, feel free to ask a new question with the **functional requirement clearly elaborated**. — BalusC, Jun 02 '11 at 18:12

score 1 · Answer 2 · answered Jun 03 '11 at 03:21

1

You can try this if you are using jQuery. It's simple:

<script>
    $(window).unload(function() {
        document.location.href='/test/dataentry';
    });
</script>

answered Jun 03 '11 at 03:21

bsimic

926
7
15

How exactly does this make difference as opposed to `window.onload = function() { ... }`? – BalusC Jun 03 '11 at 11:59
you are using onload. I'm referring to unload. This will capture the unload event and forward the user to /test/dataentry – bsimic Jun 03 '11 at 21:48

score 0 · Accepted Answer · answered Jun 04 '11 at 07:46

This can be done using ajax

<script type="text/javascript">
    function loadXMLDoc() {
        var xmlhttp;
        if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
            xmlhttp = new XMLHttpRequest();
        } else {// code for IE6, IE5
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        xmlhttp.onreadystatechange = function() {
            if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                document.getElementById("myDiv").innerHTML=xmlhttp.responseText;
            }
        }
        xmlhttp.open("GET", "/testmail/dataentry", true);
        xmlhttp.send();
    }
</script>

This is **not guaranteed** to work in all browsers. It also depends on the network speed between the client and the server. — BalusC, Jun 04 '11 at 13:18

How to call servlet from javascript

3 Answers3

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