GenericServlet Class in Servlet

GenericServlet class provides implementations of the basic life cycle methods for a servlet. GenericServlet implements the Servlet and ServletConfig interfaces. In addition, a method to append a string to the server log file is available. It has the following syntax:

void log(String s)
void log(String s, Throwable e)

ServletInputStream Class:

ServletInputStream class extends InputStream. It is implemented by the servlet container and provides an input stream that a servlet developer can use to read the data from a client request. It defines the default constructor.

int readLine(byte[ ] buffer, int offset, int size) throws IOException

ServletOutputStream Class:

ServletOutputStream class extends OutputStream. It is implemented by the servlet container and provides an output stream that a servlet developer can use to write data to client response. A default constructor is defined. It also defines the print( ) and println( ) methods, which output data to the stream.

Program:

import java.io.*;
import java.util.*;
import javax.servlet.*;
public class PostParametersServlet extends GenericServlet {
public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException {
PrintWriter pw = response.getWriter();
Enumeration e = request.getParameterNames();
while(e.hasMoreElements())
{
String pname = (String)e.nextElement();
pw.print(pname + " = ");
String pvalue = request.getParameter(pname);
pw.println(pvalue);
}
pw.close();
}
}