java code for Generate errors

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ErrorGen extends HttpServlet {

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException {

//check the servlet exception
Throwable throwable = (Throwable) request
.getAttribute("javax.servlet.error.exception");
String servletName = (String) request
.getAttribute("javax.servlet.error.servlet_name");
if (servletName == null)
servletName = "Unknown";

String requestUri = (String) request
.getAttribute("javax.servlet.error.request_uri");
if (requestUri == null)
requestUri = "Unknown";

response.setContentType("text/html");
java.io.PrintWriter out = response.getWriter();
out.println("");
out.println("");
out.println("");
out.println("");
out.println("");
if (throwable == null) {
out.println("

The error information is not available

");
out.println("Please return to the + response.encodeURL("http://www.java2s.com")
+ "\">home page");
} else {
out.println("

Here is the error information

");

out
.println("The servlet name associated with throwing the exception: "
+ servletName + "

");
out.println("The type of exception: "
+ throwable.getClass().getName() + "

");
out.println("The request URI: " + requestUri + "

");
out.println("The exception message: " + throwable.getMessage());
}
out.println("");
out.println("");
out.close();
}

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException {

doPost(request, response);
}
}