Calling method onClick of Jsp form Jsp

Question

I wish to call a method in JSP onClick, the method is on the same JSP inside scriptlet.

How should I archive this?

<%@ page import="java.io.*,java.lang.*,java.util.*,java.net.*,java.util.*,java.text.*"%>
<%@ page import="javax.activation.*,javax.mail.*,org.apache.commons.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*"%>


<%!
    public String sendMail(String to, String sub, String msg) {
        String res = null;
        System.out.println("HI");       
        return res;
    }%>

<html>
<head>
<title>Send Email using JSP</title>
</head>
<body>
    <center>
        <h1>Send Email using JSP</h1>
    </center>
    <form>  
        <label>Email To</label><br />       
            <input type="text" name="to" /><br /> 
        <label>Subject</label><br />        
            <input type="text" name="sub" /><br /> 
        <label for="body">Message</label><br />
            <input type="text" name="msg" /><br /> 
        <input type="submit" onClick="sendMail( to, sub, msg )"/>
    </form>
</body>
</html>

Note

The methods name is "sendMail", It's called on submit button I want to do the whole code in JSP only.

You need to understand the difference between JSP and Javascript, those are not execute on the same environnement — AxelH, Jan 11 '17 at 10:18
Possible duplicate of [jsp scriptlet function called from button click](http://stackoverflow.com/questions/7585472/jsp-scriptlet-function-called-from-button-click) or [invoking java scriptlet in JSP using HTML](http://stackoverflow.com/questions/16032899/invoking-java-scriptlet-in-jsp-using-html?rq=1). There are plenty of questions about this already — AxelH, Jan 11 '17 at 10:20

Jad Chahine · Answer 1 · 2017-01-11T10:48:17.883

The onclick event occurs when the user clicks on an element. This attribute has the ability to call JS functions (front end)

In your case, you want to call a JAVA function (server side) so the best way is to move the java code to a servlet and use it.

Anyway if you want to keep the JAVA function in the jsp, you can do this via ajax in this way

<script type="text/javascript">
        $(document).ready(function() {
            $('#sendMailBtn').click(function (){
                $.ajax({
                    type: "post",
                    url: "/path", 
                    data: "email=" + $('#email').val() + "&subject="+$('#subject').val() + "&msg=" + $('#msg').val(),
                    success: function(msg){      
                        //
                    }
                });
            });
        });
 </script>

AJAX is a developer's dream, because you can
Update a web page without reloading the page
Request data from a server - after the page has loaded
Receive data from a server - after the page has loaded
Send data to a server - in the background

Check the full code here

<%@ page import="java.io.*,java.lang.*,java.util.*,java.net.*,java.util.*,java.text.*"%>
<%@ page import="javax.activation.*,javax.mail.*,org.apache.commons.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*"%>


<%!
    public String sendMail(String to, String sub, String msg) {
        String res = null;
        System.out.println("HI");       
        return res;
    }
%>

<html>
    <head>
        <title>Send Email using JSP</title>
        <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"></script>
    </head>

    <body>
        <center>
            <h1>Send Email using JSP</h1>
        </center>
        <form>  
            <label>Email To</label><br />       
            <input id="email" type="text" name="to" /><br /> 
            <label>Subject</label><br />        
            <input id="subject" type="text" name="sub" /><br /> 
            <label for="body">Message</label><br />
            <input id="msg" type="text" name="msg" /><br /> 
            <input id="sendMailBtn" type="submit" />
        </form>
    </body>

    <script type="text/javascript">
        $(document).ready(function() {
            $('#sendMailBtn').click(function (){
                $.ajax({
                    type: "post",
                    url: "/path", 
                    data: "email=" + $('#email').val() + "&subject="+$('#subject').val() + "&msg=" + $('#msg').val(),
                    success: function(msg){      
                        //
                    }
                });
            });
        });
    </script>
</html>

For more information check

AJAX Introduction: http://www.w3schools.com/xml/ajax_intro.asp

onclick Event: http://www.w3schools.com/tags/ev_onclick.asp

True, but OP probably won't understand why he need to use AJAX. You should add this in your answer ;) — AxelH, Jan 11 '17 at 10:38
This doesn't connect the JAVA sendMail method with the JAVASCRIPT ajax success call, though. Any advice about that? — Atticus29, Jul 22 '20 at 03:16

score 4 · Answer 2 · answered Jan 11 '17 at 10:16

4

JSP- Executes on Server.

JavaScript - executes in browser.

No you cannot call that JSP magically from JS. However you can send an Ajax request or post the form to jsp. BTW, I strongly suggest you to move the java code to a servlet and use it.

answered Jan 11 '17 at 10:16

Suresh Atta

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Abhishek Patil · Accepted Answer · 2017-01-12T05:14:30.723

This is what I ended up doing

    <%@ page import= "java.io.*,java.lang.*,java.util.*,java.net.*,java.util.*,java.text.*"%>
    <%@ page import="javax.activation.*,javax.mail.*,org.apache.commons.*"%>
    <%@ page import="javax.servlet.http.*,javax.servlet.*"%>


    <%!
          public String sendMail(String to, String sub, String msg) {
            String res = null;      
            System.out.println("HI");      
            return res;
         }
     %>

    <%        
    String a = request.getParameter("to");
    if(a != null){
        sendMail(request.getParameter("to"),request.getParameter("sub"),request.getParameter("msg"));
    }
    %>
    <html>
    <head>
    <title>Send Email using JSP</title>
    </head>
    <body><center>
        <form action="#" method="post"> 
            <label>Email To</label><br />       
                <input type="text" name="to" /><br /> <br /> 
            <label>Subject</label><br />        
                <input type="text" name="sub" /><br /> <br /> 
            <label for="body">Message</label><br />
                <input type="text" name="msg" /><br /> <br /> 
            <input type="submit"/>
        </form>
    </center></body>
    </html>

The action="#" reloads the page, and there is a if condition which calls the required method if the parameter is not blank( Please keep in mind that by default on first call the parameter will be null ).

Calling method onClick of Jsp form Jsp

Note

3 Answers3