org.utgenome.gwt.utgb.server
Class RequestDispatcher

java.lang.Object
  org.utgenome.gwt.utgb.server.RequestDispatcher

All Implemented Interfaces:

javax.servlet.Filter

public class RequestDispatcher
extends Object
implements javax.servlet.Filter

RequestDispatcher dispatches HTTP GET/POST request to appropriate action handlers. see also http://trac.utgenome.org/project/UTGB/wiki/UTGBCore/RequestDispatcher

UTGB Request Dispatcher Mechanism

web.xml setting

Add the following description into your web.xml.

The lines param-name=base-package, param-value=(application base) specifies the location (base package name) where the RequestDispatcher? searches recursively for RequestHandler? implementations.

With the following setting, an HTTP request, e.g., http://localhost:8989/hello.action, is mapped to the request handler org.utgenome.gwt.utgb.server.app.Hello class. The upper letters are converted into the lower letters when mapping the request, e.g., Hello action can be accecced via hello.action URL.

Another example using hierarchies of actions: http://localhost:8989/admin/login.action is mapped to org.utgenome.gwt.utgb.server.Login class.

  <servlet>
  <servlet-name>dispatcher</servlet-name>
  <servlet-class>org.utgenome.gwt.utgb.server.RequestDispatcher</servlet-class>
  <init-param>
  <param-name>base-package</param-name>
  <param-value>(your web application request handler base package. e.g. org.utgenome.gwt.utgb.server.app)</param-value>
  </init-param>
  </servlet>
 
  <servlet-mapping>
  <servlet-name>dispatcher</servlet-name>
  <url-pattern>*.action</url-pattern>
  </servlet-mapping>
 

Automatic Data Binding to Request Handler

Hello.java class has serveral parameter values name and year:

 public class Hello implements RequestHandler {
        private String name = "";
        private int year = 2000;
 
        public void handle(HttpServletRequest request, HttpServletResponse response) {
                PrintWriter out = response.getWriter().println("Hello " + name + "(" + year + ")");
        }
 
        public void setName(String name) {
                this.name = name;
        }
 
        public void setYear(int year) {
                this.year = year;
        }
 }
 

Our RequestDispatcher automatically set these parameter values from a given HTTP request. For example, an HTTP request http://localhost:8989/hello.action?name=leo&year=2007 will invoke setName("leo") and setYear(2007) methods. Note that, although the query string in the HTTP request consists of string values, our BeanUtil library detects the data type to which the string should be translated by analysing the class definition. In this example, the string value "2007" is translated into an integer, 2007. The web page result of the avobe request looks like as this:

  Hello leo(2007)
 

Alternate access method: http://localhost:8989/dispathcer?actionClass=org.utgenome .gwt.utgb.server.app.hello&

Author:

leo

Constructor Summary

RequestDispatcher()

Method Summary

void	addRequestMap(RequestMap map)
void	destroy()
void	dispatchRequest(RequestURI requestURI, javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse resp, javax.servlet.FilterChain filterChain)
void	doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain filterChain)
static String	getExtension(String path)
void	init(javax.servlet.FilterConfig config)
void	initRequestMap()
static boolean	isGWTHostedMode()
static String	removeGWTModuleNamePart(String requestURI)
static void	setRequestParametersToHandler(RequestHandler handler, javax.servlet.http.HttpServletRequest req)
static String	toInternetDateFormat(long time) Converts a file-style date/time into a string form that is compatible with HTTP.

Methods inherited from class java.lang.Object

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

Constructor Detail

RequestDispatcher

public RequestDispatcher()

Method Detail

removeGWTModuleNamePart

public static String removeGWTModuleNamePart(String requestURI)

setRequestParametersToHandler

public static void setRequestParametersToHandler(RequestHandler handler,
                                                 javax.servlet.http.HttpServletRequest req)

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Filter

getExtension

public static String getExtension(String path)

doFilter

public void doFilter(javax.servlet.ServletRequest request,
                     javax.servlet.ServletResponse response,
                     javax.servlet.FilterChain filterChain)
              throws IOException,
                     javax.servlet.ServletException

Specified by:

doFilter in interface javax.servlet.Filter

Throws:

IOException

javax.servlet.ServletException

dispatchRequest

public void dispatchRequest(RequestURI requestURI,
                            javax.servlet.http.HttpServletRequest req,
                            javax.servlet.http.HttpServletResponse resp,
                            javax.servlet.FilterChain filterChain)
                     throws IOException,
                            javax.servlet.ServletException

Throws:

IOException

javax.servlet.ServletException

toInternetDateFormat

public static String toInternetDateFormat(long time)

Converts a file-style date/time into a string form that is compatible with HTTP.

isGWTHostedMode

public static boolean isGWTHostedMode()

init

public void init(javax.servlet.FilterConfig config)
          throws javax.servlet.ServletException

Specified by:

init in interface javax.servlet.Filter

Throws:

javax.servlet.ServletException

initRequestMap

public void initRequestMap()

addRequestMap

public void addRequestMap(RequestMap map)