com.purplehillsbooks.web

Class JSONServlet

java.lang.Object

javax.servlet.http.HttpServlet

com.purplehillsbooks.web.JSONServlet

public abstract class JSONServlet
extends javax.servlet.http.HttpServlet

JSONServlet is an abstract base class for a standard Java J2EE servlet that sends and receives JSON formatted data. You create a concrete subclass of this, and install it into the J2EE container for execution. You provide a handler class (that extends JSONHandler). An instance of the handler is created for every request so that you can keep important intermediate data in the handler members for processing the request efficiently. You provide a session manager class (that extends SessionManager) which holds global information for the handler as well as being able to generate your unique session objects. The fourth class that is important is the WebRequest which is a final class that makes it easier for the handler to accept and set http data.

Field Summary

Fields

Modifier and Type	Field and Description
protected SessionManager	smgr

Constructor Summary

Constructors

Constructor and Description
JSONServlet()

Method Summary

Modifier and Type	Method and Description
abstract JSONHandler	constructHandler(WebRequest wr) This is the first method you must override to return your own private handler class that actually figures out what to do with the passed in JSON objects, and what JSON Objects to return.
abstract SessionManager	constructSessionManager(ServletContext sc) This is the second method you must override to return your own private handler class that actually figures out what to do with the passed in JSON objects, and what JSON Objects to return.
static JSONObject	convertModelExceptionToJSON(java.lang.Throwable e, java.lang.String context) this converts to JSON and includes some special rules for IBPM Model exceptions
void	destroy()
void	init(ServletConfig config)
void	service(HttpServletRequest req, HttpServletResponse resp)

Methods inherited from class java.lang.Object

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

Field Detail

smgr

protected SessionManager smgr

Constructor Detail

JSONServlet

public JSONServlet()

Method Detail

constructHandler

public abstract JSONHandler constructHandler(WebRequest wr)
                                      throws java.lang.Exception

This is the first method you must override to return your own private handler class that actually figures out what to do with the passed in JSON objects, and what JSON Objects to return.

Throws:

java.lang.Exception

constructSessionManager

public abstract SessionManager constructSessionManager(ServletContext sc)
                                                throws java.lang.Exception

This is the second method you must override to return your own private handler class that actually figures out what to do with the passed in JSON objects, and what JSON Objects to return. something like return SessionManager.getSessionManagerSingleton(sc);

Throws:

java.lang.Exception

init

public void init(ServletConfig config)
          throws ServletException

Throws:

ServletException

destroy

public void destroy()

service

public void service(HttpServletRequest req,
                    HttpServletResponse resp)

convertModelExceptionToJSON

public static JSONObject convertModelExceptionToJSON(java.lang.Throwable e,
                                                     java.lang.String context)
                                              throws java.lang.Exception

this converts to JSON and includes some special rules for IBPM Model exceptions

Throws:

java.lang.Exception