Question

I would like to know what is the best way to read a text input on a jsp page?
Could anyone tell what is the difference between the two java code separated by VS?

  <input type=text id=myInput value="myInput">
  <%
        String data = request.getParameter("myinput");
   //VS
        request.setAttribute("myInput", data);  

  %>

Answer 1

I think you want the difference between a request attribute and parameter.

A request parameter is always a String (i.e. they are always represented by a String even integers, booleans, floats etc like for eg: “1”, “1.1”, “true”) and in a certain URL like: http://google.com/search?q=question&cat=images q and cat are called parameters or query parameters and their value is question and images respectively. This is an example of GET request.
POST request parameters would be those which are submitted through an html <form>.

Now request attributes are objects as opposed to parameters. And their value can only be set by using request.setAttribute("myInput", data); here data can be a String, instance or object of a Person class etc, in short data is an object.

And one more difference is you don’t have a method request.setParameter("myinput", data); there is no such method, so request parameters are only set when a html <form> is submitted or the URL contains parameters as explained above.

Now with parameters you can get them as:

String data = request.getParameter("myinput");`

even if value of "myInput" may be an int or boolean.

For an attribute you can get them as:

String data = (String) request.getAttribute("myInput");` // if "myInput" is a String
Person data = (Person) request.getAttribute("myInput");`  // if "myInput" is an instance of Person class
Long data = (Long) request.getAttribute("myInput");`  // if "myInput" is a Long

So now you know what is the different between the two codes, one reads the value from a request parameter (request.getParameter()) and other from request attribute (request.getAttribute()).

Let me know if this is not what you wanted.