001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.component;
018
019import java.io.ByteArrayInputStream;
020import java.io.IOException;
021import java.io.InputStream;
022
023import org.apache.camel.Component;
024import org.apache.camel.api.management.ManagedAttribute;
025import org.apache.camel.api.management.ManagedOperation;
026import org.apache.camel.api.management.ManagedResource;
027import org.apache.camel.api.management.mbean.ManagedResourceEndpointMBean;
028import org.apache.camel.converter.IOConverter;
029import org.apache.camel.impl.ProcessorEndpoint;
030import org.apache.camel.spi.Metadata;
031import org.apache.camel.spi.UriParam;
032import org.apache.camel.spi.UriPath;
033import org.apache.camel.util.IOHelper;
034import org.apache.camel.util.ResourceHelper;
035import org.slf4j.Logger;
036import org.slf4j.LoggerFactory;
037
038/**
039 * A useful base class for endpoints which depend on a resource
040 * such as things like Velocity or XQuery based components.
041 */
042@ManagedResource(description = "Managed ResourceEndpoint")
043public abstract class ResourceEndpoint extends ProcessorEndpoint implements ManagedResourceEndpointMBean {
044    protected final Logger log = LoggerFactory.getLogger(getClass());
045    private volatile byte[] buffer;
046    @UriPath(description = "Path to the resource, or a reference to lookup a bean in the Registry to use as the resource") @Metadata(required = "true")
047    private String resourceUri;
048    @UriParam(defaultValue = "false", description = "Sets whether to use resource content cache or not")
049    private boolean contentCache;
050
051    public ResourceEndpoint() {
052    }
053
054    public ResourceEndpoint(String endpointUri, Component component, String resourceUri) {
055        super(endpointUri, component);
056        this.resourceUri = resourceUri;
057    }
058
059    /**
060     * Gets the resource as an input stream considering the cache flag as well.
061     * <p/>
062     * If cache is enabled then the resource content is cached in an internal buffer and this content is
063     * returned to avoid loading the resource over and over again.
064     *
065     * @return the input stream
066     * @throws IOException is thrown if error loading the content of the resource to the local cache buffer
067     */
068    public InputStream getResourceAsInputStream() throws IOException {
069        // try to get the resource input stream
070        InputStream is;
071        if (isContentCache()) {
072            synchronized (this) {
073                if (buffer == null) {
074                    log.debug("Reading resource: {} into the content cache", resourceUri);
075                    is = getResourceAsInputStreamWithoutCache();
076                    buffer = IOConverter.toBytes(is);
077                    IOHelper.close(is, resourceUri, log);
078                }
079            }
080            log.debug("Using resource: {} from the content cache", resourceUri);
081            return new ByteArrayInputStream(buffer);
082        }
083
084        return getResourceAsInputStreamWithoutCache();
085    }
086
087    protected InputStream getResourceAsInputStreamWithoutCache() throws IOException {
088        return loadResource(resourceUri);
089    }
090
091    /**
092     * Loads the given resource.
093     *
094     * @param uri uri of the resource.
095     * @return the loaded resource
096     * @throws IOException is thrown if resource is not found or cannot be loaded
097     */
098    protected InputStream loadResource(String uri) throws IOException {
099        return ResourceHelper.resolveMandatoryResourceAsInputStream(getCamelContext(), uri);
100    }
101
102    @ManagedAttribute(description = "Whether the resource is cached")
103    public boolean isContentCache() {
104        return contentCache;
105    }
106
107    @ManagedOperation(description = "Clears the cached resource, forcing to re-load the resource on next request")
108    public void clearContentCache() {
109        log.debug("Clearing resource: {} from the content cache", resourceUri);
110        buffer = null;
111    }
112
113    public boolean isContentCacheCleared() {
114        return buffer == null;
115    }
116
117    @ManagedAttribute(description = "Camel context ID")
118    public String getCamelId() {
119        return getCamelContext().getName();
120    }
121
122    @ManagedAttribute(description = "Camel ManagementName")
123    public String getCamelManagementName() {
124        return getCamelContext().getManagementName();
125    }
126
127    @ManagedAttribute(description = "Endpoint service state")
128    public String getState() {
129        return getStatus().name();
130    }
131
132    /**
133     * Sets whether to use resource content cache or not.
134     */
135    public void setContentCache(boolean contentCache) {
136        this.contentCache = contentCache;
137    }
138
139    public String getResourceUri() {
140        return resourceUri;
141    }
142
143    /**
144     * Path to the resource, or a reference to lookup a bean in the Registry to use as the resource
145     *
146     * @param resourceUri  the resource path
147     */
148    public void setResourceUri(String resourceUri) {
149        this.resourceUri = resourceUri;
150    }
151}