Form parameters methods are defined in the interface ServletRequest .These are the main methods :
getParameter(String ) - Getting the parameter from the request object for the parameter name
getParameterMap() - Getting the name value map of the parameters
getParameterNames() - Returning enumeration of parameter names
getParameterValues(String) - Returns array of values for the parameter name
parameters.html :
<!DOCTYPE
html>
<html>
<head>
<meta
http-equiv="Content-Type" content="text/html;
charset=windows-1252"/>
<title>reqparameters</title>
</head>
<body>
<form method="POST"
action="getparameters">
<table border="1"
style="width: 80%;">
<tr>
<td>First
Name</td>
<td>
<input
name="first" type="text"/>
</td>
</tr>
<tr>
<td>Last
Name</td>
<td>
<input
name="last" type="text"/>
</td>
</tr>
<tr>
<td>Login
Name</td>
<td>
<input
name="login" type="text"/>
</td>
</tr>
<tr>
<td> </td>
<td>
<input
name="Submit" type="submit"
value="SubmitPage"/>
</td>
</tr>
</table>
</form>
</body>
</html>
The servlet :
package view;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
@WebServlet(name = "GetParameters", urlPatterns = { "/getparameters" })
public class GetParameters extends HttpServlet {
private static final String CONTENT_TYPE = "text/html; charset=windows-1252";
public void init(ServletConfig config) throws ServletException {
super.init(config);
}
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType(CONTENT_TYPE);
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head><title>GetParameters</title></head>");
out.println("<body>");
out.println("<p>The servlet has received a GET. This is the reply.</p>");
Enumeration params = request.getParameterNames();
while(params.hasMoreElements()) {
String name =(String)params.nextElement();
String value = request.getParameter(name);
out.println(" Name = "+name+" : Value "+value);
}
System.out.println(" Request hash Map = "+request.getParameterMap());
out.println("</body></html>");
out.close();
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
