java – 为什么在屏幕上显示异常而不是错误页面？

2024年1月15日 227次阅读

我在tomcat上使用
Java 6,jsf 1.2,spring,如果我在某个页面超时后执行操作,我会得到以下异常.

我的问题是为什么页面不会重定向到我的错误页面/error/error.jsf？

这是web.xml(我没有过滤器)：

<error-page>
    <exception-type>javax.faces.application.ViewExpiredException</exception-type>
    <location>/error/error.jsf</location>
</error-page>
  <error-page>
    <exception-type>java.lang.IllegalStateException</exception-type>
    <location>/error/error.jsf</location>
</error-page>
 <error-page>
    <exception-type>java.lang.Exception</exception-type>
    <location>/error/error.jsf</location>
</error-page>
<error-page>
    <exception-type>org.springframework.beans.factory.BeanCreationException</exception-type>
    <location>/error/error.jsf</location>
</error-page>

这是我页面上的错误消息：


   An Error Occurred:
    Error creating bean with name 'melaketViewHandler' defined in 
ServletContext resource [/WEB-INF/JSFViewHandlersContext.xml]: Instantiation 
of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: 
Could not instantiate bean class [com.ewave.meuhedet.view.melaketViewHandlers.MelaketViewHandler]: Constructor threw 
exception; nested exception is java.lang.NullPointerException

        - Stack Trace

        org.springframework.beans.factory.BeanCreationException: Error creating bean
     with name 'melaketViewHandler' defined in ServletContext resource 
    [/WEB-INF/JSFViewHandlersContext.xml]: Instantiation of bean failed; nested 
    exception is org.springframework.beans.BeanInstantiationException: Could not
     instantiate bean class [com.ewave.meuhedet.view.melaketViewHandlers.MelaketViewHandler]:
     Constructor threw exception; nested exception is java.lang.NullPointerException

      at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:254) 
...

最佳答案 我们正在使用一个自定义视图处理程序来捕获异常并重定向到错误页面：

public class ExceptionHandlingFaceletViewHandler extends FaceletViewHandler { 
  ...

  protected void handleRenderException( FacesContext context, Exception exception ) throws IOException, ELException, FacesException {  
    try {
      if( context.getViewRoot().getViewId().matches( ".*/error.jsf" ) ) {
        /*
         * This is to protect from infinite redirects if the error page itself is updated in the
         * future and has an error
         */
        LOG.fatal("Redirected back to ourselves, there must be a problem with the error.xhtml page", exception );
        return;
      }

      String contextPath = FacesContext.getCurrentInstance().getExternalContext().getRequestContextPath();
      getHttpResponseObject().sendRedirect( contextPath + "/error" );
    }
    catch( IOException ioe ) {
      LOG.fatal( "Could not process redirect to handle application error", ioe );
    }
  }

  private HttpServletResponse getHttpResponseObject() {
    return (HttpServletResponse)FacesContext.getCurrentInstance().getExternalContext().getResponse();
  }
}
点赞