21 Different ways of gathering request header values | Adv Java Servlet programming Tutorial advanc

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Note : We must use HttpServletRequest object, so our servlet class must extend from javax.servlet.http.HttpServlet class.

Approach 1: Using getHeader(-) method
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String s1=req.getHeader("user-agent"); //gives browser software name
String s2=req.getHeader("accept"); //gives MIME type supported by browser window

Here we must supply header name to get its value in getHeader(-) method

Approach 2: Using getHeaderNames() method
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Enumeration e=req.getHeaderNames();
while(e.hasMoreElements()){
String headerName=(String)e.nextElement(); //gives each header name
String headerValue=req.getHeader(headerName); // gives header value
pw.println(headerName+" - "+headerValue);
}

#How to get browser software name using which request is given to current servlet program.

use the request header of user-agent as shown below
String s1=req.getHeader("user-agent");

In servlet API there are 2 service(-,-) methods:

1) service method 1/public service method

public void service(ServletRequest req, ServletResponse res)thorws ServletException, IOException

2) service method 2/protected service method

protected void service(HttpServletRequest res, HttpServletResponse res)throws ServletException, IOException

Identify service(-,-) method on its parameter types, but not based on its modifier type.