src/org/mxchange/jcoreee/exceptions/CustomExceptionHandler.java

   1 /*
   2  * Copyright (C) 2016 Roland Haeder
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17 package org.mxchange.jcoreee.exceptions;
  18
  19 import java.text.MessageFormat;
  20 import java.util.Iterator;
  21 import java.util.Map;
  22 import javax.faces.FacesException;
  23 import javax.faces.application.NavigationHandler;
  24 import javax.faces.context.ExceptionHandler;
  25 import javax.faces.context.ExceptionHandlerWrapper;
  26 import javax.faces.context.FacesContext;
  27 import javax.faces.event.ExceptionQueuedEvent;
  28 import javax.faces.event.ExceptionQueuedEventContext;
  29 import javax.naming.Context;
  30 import javax.naming.InitialContext;
  31 import javax.naming.NamingException;
  32 import org.mxchange.jcoreeelogger.beans.local.logger.Log;
  33 import org.mxchange.jcoreeelogger.beans.local.logger.LoggerBeanLocal;
  34
  35 /**
  36  * A custom exception handler for nice output. This code is heavily based on
  37  * this [1] example.
  38  * <p>
  39  * 1: https://wmarkito.wordpress.com/2012/04/05/adding-global-exception-handling-using-jsf-2-x-exceptionhandler/
  40  * <p>
  41  * @author Roland Haeder<roland@mxchange.org>
  42  */
  43 public class CustomExceptionHandler extends ExceptionHandlerWrapper {
  44
  45         /**
  46          * Logger instance
  47          */
  48         @Log
  49         private LoggerBeanLocal loggerBeanLocal;
  50
  51         /**
  52          * Exception handler
  53          */
  54         private ExceptionHandler wrapped = null;
  55
  56         /**
  57          * Constructor with exception handler to be wrapped
  58          * <p>
  59          * @param exceptionHandler Wrapped exception handler
  60          */
  61         public CustomExceptionHandler (final ExceptionHandler exceptionHandler) {
  62                 // Call default constructor
  63                 this();
  64
  65                 // Set handler here
  66                 this.wrapped = exceptionHandler;
  67         }
  68
  69         /**
  70          * Default constructor
  71          */
  72         public CustomExceptionHandler () {
  73                 try {
  74                         // Get initial context
  75                         Context context = new InitialContext();
  76
  77                         // Lookup logger
  78                         this.loggerBeanLocal = (LoggerBeanLocal) context.lookup("java:global/jcore-logger-ejb/logger!org.mxchange.jcoreeelogger.beans.local.logger.LoggerBeanLocal"); //NOI18N
  79                 } catch (final NamingException ex) {
  80                         // Continue to throw
  81                         throw new RuntimeException(MessageFormat.format("context.lookup() failed: {0}", ex.getMessage()), ex); //NOI18N
  82                 }
  83         }
  84
  85         @Override
  86         public ExceptionHandler getWrapped () {
  87                 return this.wrapped;
  88         }
  89
  90         @Override
  91         public void handle () throws FacesException {
  92
  93                 final Iterator<ExceptionQueuedEvent> iterator = this.getUnhandledExceptionQueuedEvents().iterator();
  94
  95                 while (iterator.hasNext()) {
  96                         ExceptionQueuedEvent event = iterator.next();
  97                         ExceptionQueuedEventContext context = (ExceptionQueuedEventContext) event.getSource();
  98
  99                         // get the exception from context
 100                         Throwable t = context.getException();
 101
 102                         final FacesContext facesContext = FacesContext.getCurrentInstance();
 103                         final Map<String, Object> requestMap = facesContext.getExternalContext().getRequestMap();
 104                         final NavigationHandler nav = facesContext.getApplication().getNavigationHandler();
 105
 106                         //here you do what ever you want with exception
 107                         try {
 108
 109                                 //log error ?
 110                                 this.loggerBeanLocal.logFatal("Critical Exception.", t); //NOI18N
 111
 112                                 //redirect error page
 113                                 requestMap.put("exceptionMessage", t.getMessage()); //NOI18N
 114                                 nav.handleNavigation(facesContext, null, "exception"); //NOI18N
 115                                 facesContext.renderResponse();
 116
 117                                 // remove the comment below if you want to report the error in a jsf error message
 118                                 // @TODO: JsfUtil.addErrorMessage(t.getMessage());
 119                         } finally {
 120                                 //remove it from queue
 121                                 iterator.remove();
 122                         }
 123                 }
 124
 125                 //parent hanle
 126                 this.getWrapped().handle();
 127         }
 128
 129 }