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.wicket.util.resource;
018
019import java.io.Closeable;
020import java.io.IOException;
021import java.io.InputStream;
022import java.util.Locale;
023
024import org.apache.wicket.util.io.IClusterable;
025import org.apache.wicket.util.lang.Bytes;
026import org.apache.wicket.util.watch.IModifiable;
027
028
029/**
030 * Interface to a streamed resource. The resource stream can be retrieved by calling
031 * getInputStream(), but the resource should later be closed by calling close() on the
032 * IResourceStream (as opposed to calling close on the InputStream returned by getInputStream()).
033 * <p>
034 * Once a resource has been closed with a call to close(), it is normally possible to call
035 * getInputStream() again to retrieve a new input stream on the same resource.
036 * <p>
037 * Implementations of this interface are typically unsafe for use from multiple threads.
038 * 
039 * @author Jonathan Locke
040 */
041public interface IResourceStream extends IModifiable, IClusterable, Closeable
042{
043        /**
044         * Gets the mime type of this resource
045         * 
046         * @return The mime type of this resource, such as "image/jpeg" or "text/html". Return null to
047         *         let ResourceStreamRequestHandler handle the Content-Type automatically
048         */
049        String getContentType();
050
051        /**
052         * Gets the size of this resource
053         * 
054         * @return The size of this resource in the number of bytes, or <code>null</code> if unknown
055         */
056        Bytes length();
057
058        /**
059         * Gets the resource stream. You should not directly close this stream. Instead call the close()
060         * method on IResourceStream.
061         * 
062         * @see IResourceStream#close()
063         * @return Returns the inputStream.
064         * @throws ResourceStreamNotFoundException
065         */
066        InputStream getInputStream() throws ResourceStreamNotFoundException;
067
068        /**
069         * Closes the resource. Normally, this includes closing any underlying input stream returned by
070         * getInputStream().
071         * 
072         * @throws IOException
073         */
074        @Override
075        void close() throws IOException;
076
077        /**
078         * @return The Locale where this stream did resolve to
079         */
080        Locale getLocale();
081
082        /**
083         * This method shouldn't be used from the outside. It is used by the Loaders to set the resolved
084         * locale.
085         * 
086         * @param locale
087         *            The Locale where this stream did resolve to.
088         */
089        void setLocale(Locale locale);
090
091        /**
092         * @return The Style where this stream did resolve to
093         */
094        String getStyle();
095
096        /**
097         * This method shouldn't be used from the outside. It is used by the Loaders to set the resolved
098         * Style.
099         * 
100         * @param style
101         *            The style where this stream did resolve to.
102         */
103        void setStyle(String style);
104
105        /**
106         * @return The Variation where this stream did resolve to
107         */
108        String getVariation();
109
110        /**
111         * This method shouldn't be used from the outside. It is used by the Loaders to set the resolved
112         * variation.
113         * 
114         * @param variation
115         *            The Variation where this stream did resolve to.
116         */
117        void setVariation(String variation);
118}