A simple JSP for echoing the request.

echo.jsp

<%@ page import="java.io.Reader" %>
<%@ page import="java.io.Writer" %>
<%@ page import="java.util.Enumeration" %>
<%
Enumeration headerNames = request.getHeaderNames();
while(headerNames.hasMoreElements()) {
    String name = headerNames.nextElement().toString();
    response.setHeader(name, request.getHeader(name));
}
if (request.getMethod().equals("POST")) {
    Reader reader = request.getReader();
    Writer writer = response.getWriter();
    char[] buffer = new char[8192];
    int length;
    while ((length = reader.read(buffer)) > 0) {
        writer.write(buffer, 0, length);
    }
}
%>