org.springframework.web.servlet.handler.SimpleMappingExceptionResolver Maven / Gradle / Ivy
/*
* Copyright 2002-2005 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.servlet.handler;
import java.util.Enumeration;
import java.util.Properties;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.Ordered;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.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 DispatcherServlet.
*
* 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
* @since 22.11.2003
*/
public class SimpleMappingExceptionResolver implements HandlerExceptionResolver, Ordered {
public static final String DEFAULT_EXCEPTION_ATTRIBUTE = "exception";
protected final Log logger = LogFactory.getLog(getClass());
private int order = Integer.MAX_VALUE; // default: same as non-Ordered
private Properties exceptionMappings;
private String defaultErrorView;
private Set mappedHandlers;
private Integer defaultStatusCode;
private String exceptionAttribute = DEFAULT_EXCEPTION_ATTRIBUTE;
public void setOrder(int order) {
this.order = order;
}
public int getOrder() {
return order;
}
/**
* 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 "ServletException" would match
* javax.servlet.ServletException 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;
if (logger.isInfoEnabled()) {
logger.info("Default error view is '" + this.defaultErrorView + "'");
}
}
/**
* 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 the default HTTP status code that this exception resolver
* will apply if it resolves an error view.
*
If not specified, no status code will be applied, either
* leaving this to the controller or view, or keeping the servlet
* engine's default of 200 (OK).
* @param defaultStatusCode HTTP status code value, for example
* 500 (SC_INTERNAL_SERVER_ERROR) or 404 (SC_NOT_FOUND)
* @see javax.servlet.http.HttpServletResponse#SC_INTERNAL_SERVER_ERROR
* @see javax.servlet.http.HttpServletResponse#SC_NOT_FOUND
*/
public void setDefaultStatusCode(int defaultStatusCode) {
this.defaultStatusCode = new Integer(defaultStatusCode);
}
/**
* 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(
HttpServletRequest request, HttpServletResponse 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;
}
String viewName = null;
// Check for specific exception mappings.
if (this.exceptionMappings != null) {
int deepest = Integer.MAX_VALUE;
for (Enumeration names = this.exceptionMappings.propertyNames(); names.hasMoreElements();) {
String exceptionMapping = (String) names.nextElement();
int depth = getDepth(exceptionMapping, ex);
if (depth >= 0 && depth < deepest) {
deepest = depth;
viewName = this.exceptionMappings.getProperty(exceptionMapping);
}
}
}
// Return default error view else, if defined.
if (viewName == null && this.defaultErrorView != null) {
viewName = this.defaultErrorView;
}
if (viewName != null) {
// Apply HTTP status code for error views, if specified.
if (this.defaultStatusCode != null) {
response.setStatus(this.defaultStatusCode.intValue());
}
return getModelAndView(viewName, ex);
}
else {
return null;
}
}
/**
* 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 RollbackRuleAttribute.
* @see org.springframework.transaction.interceptor.RollbackRuleAttribute
*/
public 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 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) {
mv.addObject(this.exceptionAttribute, ex);
}
return mv;
}
}