Question

I have two text boxes in my jsp page. After entering data on first text box when user will press TAB key, then automatically control will call a servlet(in javascript) then will fill the 2nd textbox. Any help is appreciated.

Answer 1

You could subscribe to the .keydown() event of the first textbox and if the key was TAB trigger an AJAX request to the servlet:

$(function() {
    // subscribe to the keydown event
    $('#text1').keydown(function(e) {
        // when a key is pressed check if its code was 9 (TAB)
        if (e.which == 9) {
            // if TAB was pressed send an AJAX request
            // to the server passing it the currently 
            // entered value in the first textbox
            $.ajax({
                url: '/someservlet/',
                type: 'POST',
                data: { value: $(this).val() },
                success: function(result) {
                    // when the AJAX succeeds update the value of the 
                    // second textbox using the result returned by the server
                    // In this example we suppose that the servlet returns
                    // the following JSON: {"foo":"bar"}
                    $('#text2').val(result.foo);
                }
            });    
        }
    });
});

Here’s a live demo.