Request Headers In EL
Whenever an http client sends a request, it also sends the headers with it. All the headers are optional except Content-length, which is required only for POST requests. Here is the list of most commonly used headers are:
1) Accept : The MIME types the browser prefers.
2) Accept- Encoding: The types of data encodings the browser knows how to decode.
3) Accept- Charset: The character set the browser expects.
4) Content-Length: It is mostly used for POST messages, it tells how much data is attached.
5) Cookie: It is one of the most frequently used headers, it returns the cookies.
6) Accept- Language: The language the browser is expecting.
Not all the headers are specified here.
In EL we can retrieve the headers, but not as we do in scripting. To access the request headers we need a simple trick, by using that trick we will be able to access the Request Parameters.
The code of the program is given below:
<html>
<head>
<title>To retrieve a specific header</title>
</head>
<body>
<h1>By using the EL we can retrieve the request headers</h1>
<b>The Host is : ${header["host"]}</b><br>
<b>The method is : ${pageContext.request.method}</b><br>
<b>The request URI is : ${pageContext.request.requestURI}</b><br>
<b>The requested protocol is : ${pageContext.request.protocol}</b>
</body>
</html>
The output of the program is given below:
