CODEWITHSUNDEEP
javajavascripthtmljsp
Anand
Anand

Reputation: 21320

On browser refresh, java method in JSP scriptlet is getting called

I have a requirement where on clicking a button, I have to empty the text area, which is populated from a file, and need to empty the file contents also.

My jsp page looks like this

<%@page import="com.hcentive.rule.DisplayLog"%>
<%@ page import="java.lang.*" import="java.util.Scanner"  
    import="java.io.FileReader" import="java.net.*"%>  

<%  
DisplayLog log = new DisplayLog();  
log.display();  
%>  

<html>   
    <body>  
     <script>
        function validate() {
           alert("clear clicked");
           document.getElementById("rule").value = "";
           <%
                log.clear(); 
           %>
        }
        </script>   
      <br><br>
        <FORM>
            <textarea rows="20" cols="162" wrap="off" id="rule" ><%=log.getFileOutput()%></textarea>  
            <br><br>
            <input type="button" value="Clear" onclick="validate();" >
        </FORM>  
    </body> 
</html>

In above code, DisplayLog is a java class. display method is used to read file contents and write in the text area and clear method is used to empty the file contents.

It is working fine when i click the clear button it empties the text area.The problem that i am facing is that on browser refresh, log.clear() is also getting called which i don't understand.

Please someone help.

Upvotes: 0

Views: 1459

Answers (2)

Abubakkar
Abubakkar

Reputation: 15644

First, you should avoid using scriplets in JSP.

Second, instead use Ajax :

  1. Create a servlet that can do the clearing part for the file
  2. Use ajax in the onClick of your button and make a call to the servlet. Then the servlet will clear up the content on server side.

Upvotes: 1

Mark Chorley
Mark Chorley

Reputation: 2107

The fact that the call to log.clear is in a JavaScript function which is not being invoked is irrelevant here. When the page is rendered on refresh, all the scriptlets are evaluated, including this one. It is probably appropriate to clear the file contents when you submit the form rather than when the user clears the form. However if you do want to do it when the user clears the form then you could use AJAX to call out to the server and clear the log there.

Upvotes: 0

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