Passing data between jQuery and Servlet

jquery html ajax forms servlets

30,423

Solution 1

Here,

$.ajax({
    type: "POST",
    url: "CurrencyConverter",
    success: function(data) {
        $('#results').show();
        $('#results').html(data);
    }
});

you have 2 problems:

Your servlet is mapped on /CurrencyConverter.do, but yet you're trying to invoke it on /CurrencyConverter. You need to fix the URL.
You are not passing the query string dataString at all. You need to pass it as data option.

So, this should do:

$.ajax({
    type: "POST",
    url: "CurrencyConverter.do",
    data: dataString,
    success: function(data) {
        $('#results').show();
        $('#results').html(data);
    }
});

Note that although cobbling the query string together yourself may work in most cases, it will fail whenever the input values contain special characters. You want to pass a JS object along instead as shown in Akhil's answer. But much better is to just use a <form> and jQuery.serialize(). See also Simple calculator with JSP/Servlet and Ajax for a kickoff example.

Solution 2

/*
 Hi ,

just try changing the following code in javascript 

*/

  var dataString ={"amount":amount,"from":from,"to":to};

  $.ajax({
                type: "POST",
                data:dataString,
                url: "CurrencyConverter",
                success: function(data){
                //pairno ta dedomena
                $('#results').show();

                //vazo ta dedomena sto results div tag.
                $('#results').html(data);
            }
         });

30,423

Author by

Mpampinos Holmens

PLease delete my account

Updated on July 09, 2022

Comments

Mpampinos Holmens almost 2 years

I have a HTML form:

<head>

    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.5.1/jquery.js"></script>
    <script type="text/javascript">

        $(document).ready(function() {

            $('#convert').click(function(){

                //pairno tis times ap tin forma
                var amount = $('#amount').val();
                var from = $('#from').val();
                var to = $('#to').val();

                //kano ta dedomena ena koino string
                var dataString = "amount=" + amount + "&from=" + from + "&to=" + to;

                $.ajax({
                type: "POST",
                url: "CurrencyConverter",
                success: function(data){
                //pairno ta dedomena
                $('#results').show();

                //vazo ta dedomena sto results div tag.
                $('#results').html(data);
            }
         });
        });

        $('#swap').click(function() { 
            
            s1=$('#to').val();  
            s0=$('#from').val();  
            $('#to').val(s0);  
            $('#from').val(s1); 
        });
});

</script>


</head>
<body>
    <div class="data">
        <label for="from">Μετάτρεψε:</label>
        <input type="text" name="amount" id="amount" value="1" />
    </div>

    <div class="data">
        <label for="fromCurrency">από:</label>
        <select name="from" id="from">
          <option selected="" value="EUR">Euro - EUR</option>
          <option value="USD">United States Dollars - USD</option>
          <option value="GBP">United Kingdom Pounds - GBP</option>
          <option value="CAD">Canada Dollars - CAD</option>
        </select>
    </div>

    <div class="data">
        <label for="to">σε:</label>
        <select name="to" id="to">
          <option value="USD">United States Dollars - USD</option>
          <option value="GBP">United Kingdom Pounds - GBP</option>
          <option value="CAD">Canada Dollars - CAD</option>
          <option value="AUD">Australia Dollars - AUD</option>
          <option value="JPY">Japan Yen - JPY</option>
        </select>
    </div>
    <div class="data">
        <input type="submit" value="Μετατροπή">
        <input type="submit" name="swap" id="swap" value="αντάλλαξέ τα!">
    </div>
</div>

<div id="results"></div>
</body>
</html>

I want to extract the data from that form using the script on the top and send them to my servlet.

Here is my servlet code:

package com.example.web;
import com.example.model.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.lang.*;
import java.util.*;

public class CurrencySelect extends HttpServlet{

        public void doPost(HttpServletRequest request,HttpServletResponse response)throws IOException, ServletException{

            //response.setContentType("text/html;charset=UTF-8");

            String from = request.getParameter("from");

            String to = request.getParameter("to");

            String amount = request.getParameter("amount");

            CurrencyGenerator curr = new CurrencyGenerator();

            String res = curr.GetCurrency(from,to,amount);  

            out.println(res);

}

}

And here is my web.xml file:

    <?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
    Version="2.4">
    <servlet>
        <servlet-name>CurrencyConverter</servlet-name>
        <servlet-class>com.example.web.CurrencySelect</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>CodeReturn</servlet-name>
        <servlet-class>com.example.web.CodeReturn</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>Redirect</servlet-name>
        <servlet-class>com.example.web.Redirect</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>ListenerTester</servlet-name>
        <servlet-class>com.example.web.ListenerTester</servlet-class>
    </servlet>


    <servlet-mapping>
        <servlet-name>CurrencyConverter</servlet-name>
        <url-pattern>/CurrencyConverter.do</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>CodeReturn</servlet-name>
        <url-pattern>/CodeReturn.do</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>Redirect</servlet-name>
        <url-pattern>/Redirect.do</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>ListenerTester</servlet-name>
        <url-pattern>/ListenTest.do</url-pattern>
    </servlet-mapping>

    <context-param>
        <param-name>report</param-name>
        <param-value>report.html</param-value>
    </context-param> 

    <listener>
        <listener-class>com.example.model.MyServletContextListener</listener-class>
    </listener> 

</web-app>

I want to print the result in my html form page in a div I have in the end called results. I had the same script made with php and everything was working fine but with servlets. I can get my results in a new page, but I cannot take them in the same HTML page. How can I solve it?