org.springframework.web.portlet.handler.SimpleMappingExceptionResolver Maven / Gradle / Ivy
/*
* Copyright 2002-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.web.portlet.handler;
import java.util.Enumeration;
import java.util.Properties;
import java.util.Set;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;
import javax.portlet.WindowState;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.Ordered;
import org.springframework.web.portlet.HandlerExceptionResolver;
import org.springframework.web.portlet.ModelAndView;
/**
* Exception resolver that allows for mapping exception class names to view names,
* either for a list of given handlers or for all handlers in the DispatcherPortlet.
*
* Error views are analogous to error page JSPs, but can be used with any
* kind of exception including any checked one, with fine-granular mappings for
* specific handlers.
*
* @author Juergen Hoeller
* @author John A. Lewis
* @since 2.0
*/
public class SimpleMappingExceptionResolver implements HandlerExceptionResolver, Ordered {
/**
* The default name of the exception attribute: "exception".
*/
public static final String DEFAULT_EXCEPTION_ATTRIBUTE = "exception";
/** Logger available to subclasses */
protected final Log logger = LogFactory.getLog(getClass());
private int order = Integer.MAX_VALUE; // default: same as non-Ordered
private Set mappedHandlers;
private boolean renderWhenMinimized = false;
private Log warnLogger;
private Properties exceptionMappings;
private String defaultErrorView;
private String exceptionAttribute = DEFAULT_EXCEPTION_ATTRIBUTE;
public void setOrder(int order) {
this.order = order;
}
public int getOrder() {
return this.order;
}
/**
* Specify the set of handlers that this exception resolver should map.
* The exception mappings and the default error view will only apply
* to the specified handlers.
*
If no handlers set, both the exception mappings and the default error
* view will apply to all handlers. This means that a specified default
* error view will be used as fallback for all exceptions; any further
* HandlerExceptionResolvers in the chain will be ignored in this case.
*/
public void setMappedHandlers(Set mappedHandlers) {
this.mappedHandlers = mappedHandlers;
}
/**
* Set if the resolver should render a view when the portlet is in
* a minimized window. The default is "false".
* @see javax.portlet.RenderRequest#getWindowState()
* @see javax.portlet.WindowState#MINIMIZED
*/
public void setRenderWhenMinimized(boolean renderWhenMinimized) {
this.renderWhenMinimized = renderWhenMinimized;
}
/**
* Set the log category for warn logging. The name will be passed to the
* underlying logger implementation through Commons Logging, getting
* interpreted as log category according to the logger's configuration.
*
Default is no warn logging. Specify this setting to activate
* warn logging into a specific category. Alternatively, override
* the {@link #logException} method for custom logging.
* @see org.apache.commons.logging.LogFactory#getLog(String)
* @see org.apache.log4j.Logger#getLogger(String)
* @see java.util.logging.Logger#getLogger(String)
*/
public void setWarnLogCategory(String loggerName) {
this.warnLogger = LogFactory.getLog(loggerName);
}
/**
* Set the mappings between exception class names and error view names.
* The exception class name can be a substring, with no wildcard support
* at present. A value of "PortletException" would match
* javax.portet.PortletException and subclasses, for example.
*
NB: Consider carefully how specific the pattern is, and whether
* to include package information (which isn't mandatory). For example,
* "Exception" will match nearly anything, and will probably hide other rules.
* "java.lang.Exception" would be correct if "Exception" was meant to define
* a rule for all checked exceptions. With more unusual exception names such
* as "BaseBusinessException" there's no need to use a FQN.
*
Follows the same matching algorithm as RuleBasedTransactionAttribute
* and RollbackRuleAttribute.
* @param mappings exception patterns (can also be fully qualified class names)
* as keys, and error view names as values
* @see org.springframework.transaction.interceptor.RuleBasedTransactionAttribute
* @see org.springframework.transaction.interceptor.RollbackRuleAttribute
*/
public void setExceptionMappings(Properties mappings) {
this.exceptionMappings = mappings;
}
/**
* Set the name of the default error view.
* This view will be returned if no specific mapping was found.
*
Default is none.
*/
public void setDefaultErrorView(String defaultErrorView) {
this.defaultErrorView = defaultErrorView;
}
/**
* Set the name of the model attribute as which the exception should
* be exposed. Default is "exception".
* @see #DEFAULT_EXCEPTION_ATTRIBUTE
*/
public void setExceptionAttribute(String exceptionAttribute) {
this.exceptionAttribute = exceptionAttribute;
}
public ModelAndView resolveException(RenderRequest request, RenderResponse response, Object handler, Exception ex) {
// Check whether we're supposed to apply to the given handler.
if (this.mappedHandlers != null && !this.mappedHandlers.contains(handler)) {
return null;
}
// If the portlet is minimized and we don't want to render then return null.
if (WindowState.MINIMIZED.equals(request.getWindowState()) && !this.renderWhenMinimized) {
return null;
}
// Log exception, both at debug log level and at warn level, if desired.
if (logger.isDebugEnabled()) {
logger.debug("Resolving exception from handler [" + handler + "]: " + ex);
}
logException(ex, request);
// Expose ModelAndView for chosen error view.
String viewName = determineViewName(ex, request);
if (viewName != null) {
return getModelAndView(viewName, ex, request);
}
else {
return null;
}
}
/**
* Log the given exception at warn level, provided that warn logging has been
* activated through the {@link #setWarnLogCategory "warnLogCategory"} property.
*
Calls {@link #buildLogMessage} in order to determine the concrete message
* to log. Always passes the full exception to the logger.
* @param ex the exception that got thrown during handler execution
* @param request current portlet request (useful for obtaining metadata)
* @see #setWarnLogCategory
* @see #buildLogMessage
* @see org.apache.commons.logging.Log#warn(Object, Throwable)
*/
protected void logException(Exception ex, RenderRequest request) {
if (this.warnLogger != null && this.warnLogger.isWarnEnabled()) {
this.warnLogger.warn(buildLogMessage(ex, request), ex);
}
}
/**
* Build a log message for the given exception, occured during processing
* the given request.
* @param ex the exception that got thrown during handler execution
* @param request current portlet request (useful for obtaining metadata)
* @return the log message to use
*/
protected String buildLogMessage(Exception ex, RenderRequest request) {
return "Handler execution resulted in exception";
}
/**
* Determine the view name for the given exception, searching the
* {@link #setExceptionMappings "exceptionMappings"}, using the
* {@link #setDefaultErrorView "defaultErrorView"} as fallback.
* @param ex the exception that got thrown during handler execution
* @param request current portlet request (useful for obtaining metadata)
* @return the resolved view name, or null if none found
*/
protected String determineViewName(Exception ex, RenderRequest request) {
String viewName = null;
// Check for specific exception mappings.
if (this.exceptionMappings != null) {
viewName = findMatchingViewName(this.exceptionMappings, ex);
}
// Return default error view else, if defined.
if (viewName == null && this.defaultErrorView != null) {
if (logger.isDebugEnabled()) {
logger.debug("Resolving to default view '" + this.defaultErrorView +
"' for exception of type [" + ex.getClass().getName() + "]");
}
viewName = this.defaultErrorView;
}
return viewName;
}
/**
* Find a matching view name in the given exception mappings
* @param exceptionMappings mappings between exception class names and error view names
* @param ex the exception that got thrown during handler execution
* @return the view name, or null if none found
* @see #setExceptionMappings
*/
protected String findMatchingViewName(Properties exceptionMappings, Exception ex) {
String viewName = null;
String dominantMapping = null;
int deepest = Integer.MAX_VALUE;
for (Enumeration names = exceptionMappings.propertyNames(); names.hasMoreElements();) {
String exceptionMapping = (String) names.nextElement();
int depth = getDepth(exceptionMapping, ex);
if (depth >= 0 && depth < deepest) {
deepest = depth;
dominantMapping = exceptionMapping;
viewName = exceptionMappings.getProperty(exceptionMapping);
}
}
if (viewName != null && logger.isDebugEnabled()) {
logger.debug("Resolving to view '" + viewName + "' for exception of type [" + ex.getClass().getName() +
"], based on exception mapping [" + dominantMapping + "]");
}
return viewName;
}
/**
* Return the depth to the superclass matching.
*
0 means ex matches exactly. Returns -1 if there's no match.
* Otherwise, returns depth. Lowest depth wins.
*
Follows the same algorithm as
* {@link org.springframework.transaction.interceptor.RollbackRuleAttribute}.
*/
protected int getDepth(String exceptionMapping, Exception ex) {
return getDepth(exceptionMapping, ex.getClass(), 0);
}
private int getDepth(String exceptionMapping, Class exceptionClass, int depth) {
if (exceptionClass.getName().indexOf(exceptionMapping) != -1) {
// Found it!
return depth;
}
// If we've gone as far as we can go and haven't found it...
if (exceptionClass.equals(Throwable.class)) {
return -1;
}
return getDepth(exceptionMapping, exceptionClass.getSuperclass(), depth + 1);
}
/**
* Return a ModelAndView for the given request, view name and exception.
* Default implementation delegates to getModelAndView(viewName, ex).
* @param viewName the name of the error view
* @param ex the exception that got thrown during handler execution
* @param request current portlet request (useful for obtaining metadata)
* @return the ModelAndView instance
* @see #getModelAndView(String, Exception)
*/
protected ModelAndView getModelAndView(String viewName, Exception ex, RenderRequest request) {
return getModelAndView(viewName, ex);
}
/**
* Return a ModelAndView for the given view name and exception.
* Default implementation adds the specified exception attribute.
* Can be overridden in subclasses.
* @param viewName the name of the error view
* @param ex the exception that got thrown during handler execution
* @return the ModelAndView instance
* @see #setExceptionAttribute
*/
protected ModelAndView getModelAndView(String viewName, Exception ex) {
ModelAndView mv = new ModelAndView(viewName);
if (this.exceptionAttribute != null) {
if (logger.isDebugEnabled()) {
logger.debug("Exposing Exception as model attribute '" + this.exceptionAttribute + "'");
}
mv.addObject(this.exceptionAttribute, ex);
}
return mv;
}
}