package org.jboss.seam.core;
import static org.jboss.seam.InterceptionType.NEVER;
import static org.jboss.seam.annotations.Install.BUILT_IN;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import javax.faces.application.FacesMessage;
import javax.faces.application.FacesMessage.Severity;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.jboss.seam.Component;
import org.jboss.seam.ScopeType;
import org.jboss.seam.annotations.Create;
import org.jboss.seam.annotations.Install;
import org.jboss.seam.annotations.Intercept;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Scope;
import org.jboss.seam.contexts.Contexts;
import org.jboss.seam.exceptions.AnnotationErrorHandler;
import org.jboss.seam.exceptions.AnnotationRedirectHandler;
import org.jboss.seam.exceptions.ConfigErrorHandler;
import org.jboss.seam.exceptions.ConfigRedirectHandler;
import org.jboss.seam.exceptions.DebugPageHandler;
import org.jboss.seam.exceptions.ExceptionHandler;
import org.jboss.seam.log.LogProvider;
import org.jboss.seam.log.Logging;
import org.jboss.seam.util.EJB;
import org.jboss.seam.util.Reflections;
import org.jboss.seam.util.Resources;
import org.jboss.seam.util.Strings;
import org.jboss.seam.util.XML;
/**
* Holds metadata for pages defined in pages.xml, including
* page actions and page descriptions.
*
* @author Gavin King
*/
@Scope(ScopeType.APPLICATION)
@Intercept(NEVER)
@Install(precedence=BUILT_IN)
@Name("org.jboss.seam.core.exceptions")
public class Exceptions
{
private static final LogProvider log = Logging.getLogProvider(Exceptions.class);
private List<ExceptionHandler> exceptionHandlers = new ArrayList<ExceptionHandler>();
public void handle(Exception e) throws Exception
{
if ( Contexts.isConversationContextActive() )
{
Contexts.getConversationContext().set("org.jboss.seam.exception", e);
}
//build a list of the nested exceptions
List<Exception> causes = new ArrayList<Exception>();
for (Exception cause=e; cause!=null; cause=EJB.getCause(cause))
{
causes.add(cause);
}
//try to match each handler in turn
for (ExceptionHandler eh: exceptionHandlers)
{
//Try to handle most-nested exception before least-nested
for (int i=causes.size()-1; i>=0; i--)
{
Exception cause = causes.get(i);
if ( eh.isHandler(cause) )
{
if ( Contexts.isConversationContextActive() )
{
Contexts.getConversationContext().set("org.jboss.seam.handledException", cause);
}
eh.handle(cause);
return;
}
}
}
//finally, rethrow it, since no handler was found
throw e;
}
@Create
public void initialize() throws Exception
{
ExceptionHandler anyhandler1 = parse("/WEB-INF/exceptions.xml"); //deprecated
ExceptionHandler anyhandler2 = parse("/WEB-INF/pages.xml");
exceptionHandlers.add( new AnnotationRedirectHandler() );
exceptionHandlers.add( new AnnotationErrorHandler() );
if ( Init.instance().isDebug() )
{
exceptionHandlers.add( new DebugPageHandler() );
}
if (anyhandler1!=null) exceptionHandlers.add(anyhandler1);
if (anyhandler2!=null) exceptionHandlers.add(anyhandler2);
}
private ExceptionHandler parse(String fileName) throws DocumentException, ClassNotFoundException
{
ExceptionHandler anyhandler = null;
InputStream stream = Resources.getResourceAsStream(fileName);
if (stream!=null)
{
log.debug("reading exception mappings from " + fileName);
List<Element> elements = XML.getRootElement(stream).elements("exception");
for (final Element exception: elements)
{
String className = exception.attributeValue("class");
if (className==null)
{
anyhandler = createHandler(exception, Exception.class);
}
else
{
ExceptionHandler handler = createHandler( exception, Reflections.classForName(className) );
if (handler!=null) exceptionHandlers.add(handler);
}
}
}
return anyhandler;
}
private ExceptionHandler createHandler(Element exception, final Class clazz)
{
final boolean endConversation = exception.elementIterator("end-conversation").hasNext();
Element redirect = exception.element("redirect");
if (redirect!=null)
{
final String viewId = redirect.attributeValue("view-id");
Element messageElement = redirect.element("message");
final String message = messageElement==null ? null : messageElement.getTextTrim();
String severityName = messageElement==null ? null : messageElement.attributeValue("severity");
Severity severity = severityName==null ?
FacesMessage.SEVERITY_INFO :
Pages.getFacesMessageValuesMap().get( severityName.toUpperCase() );
return new ConfigRedirectHandler(viewId, clazz, endConversation, message, severity);
}
Element error = exception.element("http-error");
if (error!=null)
{
String errorCode = error.attributeValue("error-code");
final int code = Strings.isEmpty(errorCode) ?
500 : Integer.parseInt(errorCode);
Element messageElement = error.element("message");
final String message = messageElement==null ? null : messageElement.getTextTrim();
return new ConfigErrorHandler(message, endConversation, clazz, code);
}
return null;
}
public static Exceptions instance()
{
if ( !Contexts.isApplicationContextActive() )
{
throw new IllegalStateException("No active application context");
}
return (Exceptions) Component.getInstance(Exceptions.class, ScopeType.APPLICATION);
}
}