1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.fileupload;
18
19 import java.io.IOException;
20 import java.io.InputStream;
21
22
23 /**
24 * <p> This interface provides access to a file or form item that was
25 * received within a <code>multipart/form-data</code> POST request.
26 * The items contents are retrieved by calling {@link #openStream()}.</p>
27 * <p>Instances of this class are created by accessing the
28 * iterator, returned by
29 * {@link FileUploadBase#getItemIterator(RequestContext)}.</p>
30 * <p><em>Note</em>: There is an interaction between the iterator and
31 * its associated instances of {@link FileItemStream}: By invoking
32 * {@link java.util.Iterator#hasNext()} on the iterator, you discard all data,
33 * which hasn't been read so far from the previous data.</p>
34 */
35 public interface FileItemStream extends FileItemHeadersSupport {
36 /**
37 * This exception is thrown, if an attempt is made to read
38 * data from the {@link InputStream}, which has been returned
39 * by {@link FileItemStream#openStream()}, after
40 * {@link java.util.Iterator#hasNext()} has been invoked on the
41 * iterator, which created the {@link FileItemStream}.
42 */
43 public static class ItemSkippedException extends IOException {
44 /**
45 * The exceptions serial version UID, which is being used
46 * when serializing an exception instance.
47 */
48 private static final long serialVersionUID = -7280778431581963740L;
49 }
50
51 /** Creates an {@link InputStream}, which allows to read the
52 * items contents.
53 * @return The input stream, from which the items data may
54 * be read.
55 * @throws IllegalStateException The method was already invoked on
56 * this item. It is not possible to recreate the data stream.
57 * @throws IOException An I/O error occurred.
58 * @see ItemSkippedException
59 */
60 InputStream openStream() throws IOException;
61
62 /**
63 * Returns the content type passed by the browser or <code>null</code> if
64 * not defined.
65 *
66 * @return The content type passed by the browser or <code>null</code> if
67 * not defined.
68 */
69 String getContentType();
70
71 /**
72 * Returns the original filename in the client's filesystem, as provided by
73 * the browser (or other client software). In most cases, this will be the
74 * base file name, without path information. However, some clients, such as
75 * the Opera browser, do include path information.
76 *
77 * @return The original filename in the client's filesystem.
78 */
79 String getName();
80
81 /**
82 * Returns the name of the field in the multipart form corresponding to
83 * this file item.
84 *
85 * @return The name of the form field.
86 */
87 String getFieldName();
88
89 /**
90 * Determines whether or not a <code>FileItem</code> instance represents
91 * a simple form field.
92 *
93 * @return <code>true</code> if the instance represents a simple form
94 * field; <code>false</code> if it represents an uploaded file.
95 */
96 boolean isFormField();
97 }