通过web.xml进行异常和错误处理配置

Question

I am using Apache MyFaces and need to handle ViewExpiredException differently than other internal server errors.But I find that if I include error-code, 500; then in ViewExpiredException error also it takes the path of error-code.

Below is web.xml configuration:

<error-page>
    <exception-type>javax.faces.application.ViewExpiredException</exception-type>
    <location>/login.xhtml?faces-redirect=true</location>
</error-page> 

<error-page>
    <error-code>500</error-code>
    <location>/error.xhtml</location>
</error-page>

How to ensure that i can redirect to different URL for the above two case? Referred multiple error-code configuration web.xml and I am fine to replace the location with a single servlet; but how to capture the error in servlet?

Answer 1

对于ViewExpiredException，为什么不尝试通过CustomExceptionHandler处理异常，并通过handle（）方法将用户重定向到所需的任何Page

Answer 2

I had 2 issues here:

a. Identify javax.faces.application.ViewExpiredException and redirect to /login.xhtml?faces-redirect=true. Without faces-redirect, redirecting to XHTML page will throw error

b. Ensure that other error with status code 500 is redirected to appropriate page.

These are resolved by:

1> Created a servlet which checks for HTTP code, and then checks if the error is due to ViewExpiredException or not. Based upon the error condition, the servlet forwards the request to specific URL.

 if (request.getAttribute("javax.servlet.error.status_code") == 500) { excep = (Class<? extends Exception>) request .getAttribute("javax.servlet.error.exception_type"); if (excep != null) { if (excep.getCanonicalName().equalsIgnoreCase( "javax.faces.application.ViewExpiredException")) { //you can forward to another page like /login.xhtml?faces-redirect=true } else { //you can forward to different page with error message } } } 

2> Change in web.xml to forward all 500 exception to this servlet

 <error-page> <error-code>500</error-code> <location>/error</location><!-- here error is name of servlet --> </error-page>