How to Retrieve URL Parameters in JSP?

Obtaining URL Parameters in JSP

In JavaServer Pages (JSP), retrieving parameters from a URL is a crucial task. This article explores various methods to accomplish this.

The Unified Expression Language (EL) provides several implicit objects, including "param". This object maps request parameter names to single values.

Using EL:

To extract the "accountID" parameter from the URL "www.somesite.com/Transaction_List.jsp?accountID=5", you can utilize EL as follows:

<code class="jsp">${param.accountID}</code>

This expression will evaluate to the string "5".

Using JSP Scriptlets:

While scriptlets are discouraged, you can also obtain URL parameters using them:

<code class="jsp"><%
  String accountId = request.getParameter("accountID");
%></code>

After executing this scriptlet, the "accountId" variable will store the value "5".

Additional Considerations:

EL provides additional implicit objects such as "paramValues" for accessing multiple values associated with a parameter. The "request" object also allows access to the URL parameters through its "getParameter()" and "getParameterValues()" methods.

By employing these techniques, developers can effectively retrieve and utilize URL parameters within JSP applications.

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