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 */
017 package org.apache.commons.fileupload;
018
019 import java.io.IOException;
020 import java.io.InputStream;
021
022
023 /**
024 * <p> This interface provides access to a file or form item that was
025 * received within a <code>multipart/form-data</code> POST request.
026 * The items contents are retrieved by calling {@link #openStream()}.</p>
027 * <p>Instances of this class are created by accessing the
028 * iterator, returned by
029 * {@link FileUploadBase#getItemIterator(RequestContext)}.</p>
030 * <p><em>Note</em>: There is an interaction between the iterator and
031 * its associated instances of {@link FileItemStream}: By invoking
032 * {@link java.util.Iterator#hasNext()} on the iterator, you discard all data,
033 * which hasn't been read so far from the previous data.</p>
034 */
035 public interface FileItemStream extends FileItemHeadersSupport {
036 /**
037 * This exception is thrown, if an attempt is made to read
038 * data from the {@link InputStream}, which has been returned
039 * by {@link FileItemStream#openStream()}, after
040 * {@link java.util.Iterator#hasNext()} has been invoked on the
041 * iterator, which created the {@link FileItemStream}.
042 */
043 public static class ItemSkippedException extends IOException {
044 /**
045 * The exceptions serial version UID, which is being used
046 * when serializing an exception instance.
047 */
048 private static final long serialVersionUID = -7280778431581963740L;
049 }
050
051 /** Creates an {@link InputStream}, which allows to read the
052 * items contents.
053 * @return The input stream, from which the items data may
054 * be read.
055 * @throws IllegalStateException The method was already invoked on
056 * this item. It is not possible to recreate the data stream.
057 * @throws IOException An I/O error occurred.
058 * @see ItemSkippedException
059 */
060 InputStream openStream() throws IOException;
061
062 /**
063 * Returns the content type passed by the browser or <code>null</code> if
064 * not defined.
065 *
066 * @return The content type passed by the browser or <code>null</code> if
067 * not defined.
068 */
069 String getContentType();
070
071 /**
072 * Returns the original filename in the client's filesystem, as provided by
073 * the browser (or other client software). In most cases, this will be the
074 * base file name, without path information. However, some clients, such as
075 * the Opera browser, do include path information.
076 *
077 * @return The original filename in the client's filesystem.
078 */
079 String getName();
080
081 /**
082 * Returns the name of the field in the multipart form corresponding to
083 * this file item.
084 *
085 * @return The name of the form field.
086 */
087 String getFieldName();
088
089 /**
090 * Determines whether or not a <code>FileItem</code> instance represents
091 * a simple form field.
092 *
093 * @return <code>true</code> if the instance represents a simple form
094 * field; <code>false</code> if it represents an uploaded file.
095 */
096 boolean isFormField();
097 }