com.microdeveloper.servlets.io
Class PostRedirect

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          com.microdeveloper.servlets.io.PostRedirect

All Implemented Interfaces:

Serializable, Servlet, ServletConfig

public class PostRedirect
extends HttpServlet

PostRedirect will accept a request and redirect it as a post type request to another destination URL allowing the instantiated servlet to override certain parameters from the original post.

An example of usage would be to invoke a report, passing parameters such as order number, but letting a custom method determine the exact report to run for the given request or user. Another usage would be to validate or remove unwanted or unsafe parameters before invoking the target.

Finally, by using the redirection, the actual target is not visible in the URL.

Since:

1.7

Version:

1.0

Author:

Gregg Lagnese

See Also:

Serialized Form

Constructor Summary

PostRedirect()

Method Summary

void	destroy() Destroys the servlet.
protected void	doGet(HttpServletRequest request, HttpServletResponse response) Handles the HTTP GET method.
protected void	doPost(HttpServletRequest request, HttpServletResponse response) Handles the HTTP POST method.
String	getServletInfo() Returns a short description of the servlet.
void	init(ServletConfig config) Initializes the servlet.
protected void	processRequest(HttpServletRequest request, HttpServletResponse response) Processes requests for both HTTP GET and POST methods.
void	sendRedirect(HttpServletRequest request, HttpServletResponse response) Process the redirection to the destination.
protected Hashtable	setOverrideParams(Hashtable params) Overrides and potentially replaces original request parameters
protected void	setServletProperties(String paramFile) The servlet properties which defines the default protocol (scheme), server, port, and path.

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletName, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PostRedirect

public PostRedirect()

Method Detail

getServletInfo

public String getServletInfo()

Returns a short description of the servlet.

Specified by:

getServletInfo in interface Servlet

Overrides:

getServletInfo in class GenericServlet

Returns:

Short description

destroy

public void destroy()

Destroys the servlet.

Specified by:

destroy in interface Servlet

Overrides:

destroy in class GenericServlet

init

public void init(ServletConfig config)
          throws ServletException

Initializes the servlet.

Specified by:

init in interface Servlet

Overrides:

init in class GenericServlet

Parameters:

config - Configuration for the servlet

Throws:

ServletException - Standard servlet exception

sendRedirect

public void sendRedirect(HttpServletRequest request,
                         HttpServletResponse response)
                  throws ServletException,
                         IOException

Process the redirection to the destination. Uses customUrl to allow the overriding of the fetched parameters so they can be pre-processed by custom routines. This is not required however and the default method does nothing to the parameters unless overridden.

Parameters:

request - servlet request

response - servlet response

Throws:

ServletException - standard servlet exception

IOException - standard io exception

doGet

protected void doGet(HttpServletRequest request,
                     HttpServletResponse response)
              throws ServletException,
                     IOException

Handles the HTTP GET method.

Overrides:

doGet in class HttpServlet

Parameters:

request - servlet request

response - servlet response

Throws:

ServletException - standard servlet exception

IOException - standard io exception

doPost

protected void doPost(HttpServletRequest request,
                      HttpServletResponse response)
               throws ServletException,
                      IOException

Handles the HTTP POST method.

Overrides:

doPost in class HttpServlet

Parameters:

request - servlet request

response - servlet response

Throws:

ServletException - standard servlet exception

IOException - standard io exception

processRequest

protected void processRequest(HttpServletRequest request,
                              HttpServletResponse response)
                       throws ServletException,
                              IOException

Processes requests for both HTTP GET and POST methods.

Parameters:

request - servlet request

response - servlet response

Throws:

ServletException - standard servlet exception

IOException - standard io exception

setServletProperties

protected void setServletProperties(String paramFile)
                             throws ServletException,
                                    IOException

The servlet properties which defines the default protocol (scheme), server, port, and path. Only the default server must be set in the properties file. If this is not present, the servlet will not initialize. The default url would be HTTP://[server]:80

This method can be overriden to add additional properties, such as default database credentials, but must always include the following:

• defaultServer
• defaultScheme
• defaultPath
• defaultPort

These elements must be present even if they are absent from the actual parameter file itself.

You can also use the setOverrideParams method to introduce custom parameters instead of overriding this method. Just fetch additional parameters there and add them to the post variables (for logon credentials for example)

Parameters:

paramFile - full path to the parameter file

Throws:

ServletException - standard servlet exception

IOException - standard io exception

setOverrideParams

protected Hashtable setOverrideParams(Hashtable params)

Overrides and potentially replaces original request parameters

Parameters:

params - Original request parameter Hashtable

Returns:

Final parameters as a Hashtable