Difference between request parameter and request attribute

[Akhilesh Murthy]

Hi,

What are the key differences between request parameter and request attribute?

Thanks

[Frits Walraven]

Hi,

What are the key differences between request parameter and request attribute?

Parameter:

Read only

Contains submitted data

Strings

Attribute:

Read/Write

Doesn't contain submitted data

Can be any Object

Regards,
Frits

[Sharad Kharya]

Request Parameter are submitted with request URL and you can get thos parameter values using getParameter(String name)

Later if you want, you can set parameters in request scope, which will be accessed in other included/forwarded servlet/JSP while using RequestDispatcher mechanism.


java.lang.String getParameter(java.lang.String name) ----- Returns the value of a request parameter as a String, or null if the parameter does not exist.

java.lang.Object getAttribute(java.lang.String name) ------- Returns the value of the named attribute as an Object, or null if no attribute of the given name exists.

[Frits Walraven]

Later if you want, you can set parameters in request scope, which will be accessed in other included/forwarded servlet/JSP while using RequestDispatcher mechanism.

Be careful here: there is no ServletRequest.setParameter() or HttpServletRequest.setParameter() method, nor is there a RequestDispatcher.addParameter() of RequestDispatcher.setParameter() method.

What you are describing is a mechanism in a JSP where you can use the <jsp:param> in following tag:

<jsp:forward page="animalHouse.jsp">
      <jsp:param name="animaltypes" value="cat" />
</jsp:forward>

These additional parameters are added to the request, but only for the duration of the include or forward.

Regards,
Frits