/*
* Copyright 2002-2014 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.integration.resource;
import java.util.Arrays;
import java.util.Collection;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.MessageSource;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.integration.endpoint.AbstractMessageSource;
import org.springframework.integration.util.CollectionFilter;
import org.springframework.messaging.MessagingException;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;
import org.springframework.util.ObjectUtils;
/**
* Implementation of {@link MessageSource} based on {@link ResourcePatternResolver} which will
* attempt to resolve {@link Resource}s based on the pattern specified.
*
* @author Oleg Zhurakousky
* @author Mark Fisher
* @author Gary Russell
* @since 2.1
*/
public class ResourceRetrievingMessageSource extends AbstractMessageSource<Resource[]>
implements ApplicationContextAware, InitializingBean {
private final String pattern;
private volatile ApplicationContext applicationContext;
private volatile ResourcePatternResolver patternResolver;
private volatile CollectionFilter<Resource> filter;
public ResourceRetrievingMessageSource(String pattern) {
Assert.hasText(pattern, "pattern must not be empty");
this.pattern = pattern;
}
public void setPatternResolver(ResourcePatternResolver patternResolver) {
this.patternResolver = patternResolver;
}
public void setFilter(CollectionFilter<Resource> filter) {
this.filter = filter;
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) {
this.applicationContext = applicationContext;
}
@Override
public String getComponentType() {
return "resource-inbound-channel-adapter";
}
@Override
public void afterPropertiesSet() throws Exception {
super.afterPropertiesSet();
if (this.patternResolver == null) {
this.patternResolver = this.applicationContext;
}
Assert.notNull(this.patternResolver, "no 'patternResolver' available");
}
@Override
protected Resource[] doReceive() {
try {
Resource[] resources = this.patternResolver.getResources(this.pattern);
if (ObjectUtils.isEmpty(resources)) {
resources = null;
}
else if (this.filter != null) {
Collection<Resource> filteredResources = this.filter.filter(Arrays.asList(resources));
if (CollectionUtils.isEmpty(filteredResources)) {
resources = null;
}
else {
resources = filteredResources.toArray(new Resource[filteredResources.size()]);
}
}
return resources;
}
catch (Exception e) {
throw new MessagingException("Attempt to retrieve Resources failed", e);
}
}
}