How to get the intended URL from a request

[Rajesh Khan]

Hi my filter is managing permissions for different pages. Is it possible to get the url destination of the request ?? If so how ??

[Bosun Bello]

If I understand you correctly, you can use getRequestURI method to get, and possibly save it for later use.

[Rajesh Khan]

Bosun Bello wrote:If I understand you correctly, you can use getRequestURI method to get, and possibly save it for later use.

It seems that method is not available in

	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException 
	{       }

[Bear Bibeault]

Sure it is. You need to cast the request instance to HttpServletRequest.

[Rajesh Khan]

Bear Bibeault wrote:Sure it is. You need to cast the request instance to HttpServletRequest.

Thanks that did the trick

[Rajesh Khan]

Okay so with a little debugging and trial and error i realized that the following works (both filter and servlet)

String username = (String) ((HttpServletRequest)request).getSession().getAttribute("uname");

But the following just throws an exception (I Wonder what the difference is)

String uname = ((HttpServletRequest)request).getSession().getAttribute("uname").toString();

Exception is

java.lang.NullPointerException
	at ims.filters.Filtername.doFilter(PermissionFilter.java:41)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:291)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
	at java.lang.Thread.run(Thread.java:722)

[Bosun Bello]

In the first case, you are casting, however in the second, you are calling a method on a variable that is null. Hence, the reason for the null pointer. With casting, if what you are casting returns null, your fast will return exactly that.

[Rajesh Khan]

Bosun Bello wrote:In the first case, you are casting, however in the second, you are calling a method on a variable that is null. Hence, the reason for the null pointer. With casting, if what you are casting returns null, your fast will return exactly that.

That makes sense.. thanks..