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*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.struts2.dispatcher.mapper;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import org.apache.struts2.StrutsConstants;
import com.opensymphony.xwork2.config.ConfigurationManager;
import com.opensymphony.xwork2.inject.Container;
import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;
/**
* <!-- START SNIPPET: description -->
*
* A composite action mapper that is capable of delegating to a series of {@link ActionMapper} if the former
* failed to obtained a valid {@link ActionMapping} or uri.
* <p/>
* It is configured through struts.properties.
* <p/>
* For example, with the following entries in struts.properties
* <p/>
* <pre>
* <bean type="org.apache.struts2.dispatcher.mapper.ActionMapper" name="struts"
* class="org.apache.struts2.dispatcher.mapper.CompositeActionMapper" />
* <constant name="struts.mapper.composite"
* value="org.apache.struts2.dispatcher.mapper.DefaultActionMapper,org.apache.struts2.dispatcher.mapper.RestfulActionMapper,org.apache.struts2.dispatcher.mapper.Restful2ActionMapper" />
* </pre>
* <p/>
* When {@link CompositeActionMapper#getMapping(HttpServletRequest, ConfigurationManager)} or
* {@link CompositeActionMapper#getUriFromActionMapping(ActionMapping)} is invoked,
* {@link CompositeActionMapper} would go through these {@link ActionMapper}s in sequence
* starting from {@link ActionMapper} identified by 'struts.mapper.composite.1', followed by
* 'struts.mapper.composite.2' and finally 'struts.mapper.composite.3' (in this case) until either
* one of the {@link ActionMapper} return a valid result (not null) or it runs out of {@link ActionMapper}
* in which case it will just return null for both
* {@link CompositeActionMapper#getMapping(HttpServletRequest, ConfigurationManager)} and
* {@link CompositeActionMapper#getUriFromActionMapping(ActionMapping)} methods.
* <p/>
*
* For example with the following in struts-*.xml :-
* <pre>
* <bean type="org.apache.struts2.dispatcher.mapper.ActionMapper" name="struts"
* class="org.apache.struts2.dispatcher.mapper.CompositeActionMapper" />
* <constant name="struts.mapper.composite"
* value="org.apache.struts2.dispatcher.mapper.DefaultActionMapper,foo.bar.MyActionMapper,foo.bar.MyAnotherActionMapper" />
* </pre>
* <p/>
* <code>CompositeActionMapper</code> will be configured with 3 ActionMapper, namely
* "DefaultActionMapper", "MyActionMapper" and "MyAnotherActionMapper".
* <code>CompositeActionMapper</code> would consult each of them in order described above.
*
* <!-- END SNIPPET: description -->
*
* @see ActionMapper
* @see ActionMapping
*
* @version $Date$ $Id$
*/
public class CompositeActionMapper implements ActionMapper {
private static final Logger LOG = LoggerFactory.getLogger(CompositeActionMapper.class);
protected Container container;
protected List<ActionMapper> actionMappers = new ArrayList<ActionMapper>();
@Inject
public void setContainer(Container container) {
this.container = container;
}
@Inject(StrutsConstants.STRUTS_MAPPER_COMPOSITE)
public void setActionMappers(String list) {
if (list != null) {
String[] arr = list.split(",");
for (String name : arr) {
Object obj = container.getInstance(ActionMapper.class, name);
if (obj != null) {
actionMappers.add((ActionMapper) obj);
}
}
}
}
public ActionMapping getMapping(HttpServletRequest request, ConfigurationManager configManager) {
for (ActionMapper actionMapper : actionMappers) {
ActionMapping actionMapping = actionMapper.getMapping(request, configManager);
if (LOG.isDebugEnabled()) {
LOG.debug("Using ActionMapper "+actionMapper);
}
if (actionMapping == null) {
if (LOG.isDebugEnabled()) {
LOG.debug("ActionMapper "+actionMapper+" failed to return an ActionMapping (null)");
}
}
else {
return actionMapping;
}
}
if (LOG.isDebugEnabled()) {
LOG.debug("exhausted from ActionMapper that could return an ActionMapping");
}
return null;
}
public ActionMapping getMappingFromActionName(String actionName) {
for (ActionMapper actionMapper : actionMappers) {
ActionMapping actionMapping = actionMapper.getMappingFromActionName(actionName);
if (LOG.isDebugEnabled()) {
LOG.debug("Using ActionMapper "+actionMapper);
}
if (actionMapping == null) {
if (LOG.isDebugEnabled()) {
LOG.debug("ActionMapper "+actionMapper+" failed to return an ActionMapping (null)");
}
}
else {
return actionMapping;
}
}
if (LOG.isDebugEnabled()) {
LOG.debug("exhausted from ActionMapper that could return an ActionMapping");
}
return null;
}
public String getUriFromActionMapping(ActionMapping mapping) {
for (ActionMapper actionMapper : actionMappers) {
String uri = actionMapper.getUriFromActionMapping(mapping);
if (LOG.isDebugEnabled()) {
LOG.debug("Using ActionMapper "+actionMapper);
}
if (uri == null) {
if (LOG.isDebugEnabled()) {
LOG.debug("ActionMapper "+actionMapper+" failed to return an ActionMapping (null)");
}
}
else {
return uri;
}
}
if (LOG.isDebugEnabled()) {
LOG.debug("exhausted from ActionMapper that could return a uri");
}
return null;
}
}