001: /*
002: * Copyright 2001-2004 The Apache Software Foundation
003: *
004: * Licensed under the Apache License, Version 2.0 (the "License");
005: * you may not use this file except in compliance with the License.
006: * You may obtain a copy of the License at
007: *
008: * http://www.apache.org/licenses/LICENSE-2.0
009: *
010: * Unless required by applicable law or agreed to in writing, software
011: * distributed under the License is distributed on an "AS IS" BASIS,
012: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013: * See the License for the specific language governing permissions and
014: * limitations under the License.
015: */
016: package net.jforum.util.legacy.commons.fileupload;
017:
018: import java.io.File;
019: import java.io.IOException;
020: import java.io.InputStream;
021: import java.io.OutputStream;
022: import java.io.Serializable;
023: import java.io.UnsupportedEncodingException;
024:
025: /**
026: * <p> This class represents a file or form item that was received within a
027: * <code>multipart/form-data</code> POST request.
028: *
029: * <p> After retrieving an instance of this class from a {@link
030: * org.apache.commons.fileupload.FileUpload FileUpload} instance (see
031: * {@link org.apache.commons.fileupload.FileUpload
032: * #parseRequest(javax.servlet.http.HttpServletRequest)}), you may
033: * either request all contents of the file at once using {@link #get()} or
034: * request an {@link java.io.InputStream InputStream} with
035: * {@link #getInputStream()} and process the file without attempting to load
036: * it into memory, which may come handy with large files.
037: *
038: * <p> While this interface does not extend
039: * <code>javax.activation.DataSource</code> per se (to avoid a seldom used
040: * dependency), several of the defined methods are specifically defined with
041: * the same signatures as methods in that interface. This allows an
042: * implementation of this interface to also implement
043: * <code>javax.activation.DataSource</code> with minimal additional work.
044: *
045: * @author <a href="mailto:Rafal.Krzewski@e-point.pl">Rafal Krzewski</a>
046: * @author <a href="mailto:sean@informage.net">Sean Legassick</a>
047: * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
048: * @author <a href="mailto:martinc@apache.org">Martin Cooper</a>
049: *
050: * @version $Id: FileItem.java,v 1.3 2005/07/26 03:05:01 rafaelsteil Exp $
051: */
052: public interface FileItem extends Serializable {
053:
054: // ------------------------------- Methods from javax.activation.DataSource
055:
056: /**
057: * Returns an {@link java.io.InputStream InputStream} that can be
058: * used to retrieve the contents of the file.
059: *
060: * @return An {@link java.io.InputStream InputStream} that can be
061: * used to retrieve the contents of the file.
062: *
063: * @exception IOException if an error occurs.
064: */
065: InputStream getInputStream() throws IOException;
066:
067: /**
068: * Returns the content type passed by the browser or <code>null</code> if
069: * not defined.
070: *
071: * @return The content type passed by the browser or <code>null</code> if
072: * not defined.
073: */
074: String getContentType();
075:
076: /**
077: * Returns the original filename in the client's filesystem, as provided by
078: * the browser (or other client software). In most cases, this will be the
079: * base file name, without path information. However, some clients, such as
080: * the Opera browser, do include path information.
081: *
082: * @return The original filename in the client's filesystem.
083: */
084: String getName();
085:
086: // ------------------------------------------------------- FileItem methods
087:
088: /**
089: * Provides a hint as to whether or not the file contents will be read
090: * from memory.
091: *
092: * @return <code>true</code> if the file contents will be read from memory;
093: * <code>false</code> otherwise.
094: */
095: boolean isInMemory();
096:
097: /**
098: * Returns the size of the file item.
099: *
100: * @return The size of the file item, in bytes.
101: */
102: long getSize();
103:
104: /**
105: * Returns the contents of the file item as an array of bytes.
106: *
107: * @return The contents of the file item as an array of bytes.
108: */
109: byte[] get();
110:
111: /**
112: * Returns the contents of the file item as a String, using the specified
113: * encoding. This method uses {@link #get()} to retrieve the
114: * contents of the item.
115: *
116: * @param encoding The character encoding to use.
117: *
118: * @return The contents of the item, as a string.
119: *
120: * @exception UnsupportedEncodingException if the requested character
121: * encoding is not available.
122: */
123: String getString(String encoding)
124: throws UnsupportedEncodingException;
125:
126: /**
127: * Returns the contents of the file item as a String, using the default
128: * character encoding. This method uses {@link #get()} to retrieve the
129: * contents of the item.
130: *
131: * @return The contents of the item, as a string.
132: */
133: String getString();
134:
135: /**
136: * A convenience method to write an uploaded item to disk. The client code
137: * is not concerned with whether or not the item is stored in memory, or on
138: * disk in a temporary location. They just want to write the uploaded item
139: * to a file.
140: * <p>
141: * This method is not guaranteed to succeed if called more than once for
142: * the same item. This allows a particular implementation to use, for
143: * example, file renaming, where possible, rather than copying all of the
144: * underlying data, thus gaining a significant performance benefit.
145: *
146: * @param file The <code>File</code> into which the uploaded item should
147: * be stored.
148: *
149: * @exception Exception if an error occurs.
150: */
151: void write(File file) throws Exception;
152:
153: /**
154: * Deletes the underlying storage for a file item, including deleting any
155: * associated temporary disk file. Although this storage will be deleted
156: * automatically when the <code>FileItem</code> instance is garbage
157: * collected, this method can be used to ensure that this is done at an
158: * earlier time, thus preserving system resources.
159: */
160: void delete();
161:
162: /**
163: * Returns the name of the field in the multipart form corresponding to
164: * this file item.
165: *
166: * @return The name of the form field.
167: */
168: String getFieldName();
169:
170: /**
171: * Sets the field name used to reference this file item.
172: *
173: * @param name The name of the form field.
174: */
175: void setFieldName(String name);
176:
177: /**
178: * Determines whether or not a <code>FileItem</code> instance represents
179: * a simple form field.
180: *
181: * @return <code>true</code> if the instance represents a simple form
182: * field; <code>false</code> if it represents an uploaded file.
183: */
184: boolean isFormField();
185:
186: /**
187: * Specifies whether or not a <code>FileItem</code> instance represents
188: * a simple form field.
189: *
190: * @param state <code>true</code> if the instance represents a simple form
191: * field; <code>false</code> if it represents an uploaded file.
192: */
193: void setFormField(boolean state);
194:
195: /**
196: * Returns an {@link java.io.OutputStream OutputStream} that can
197: * be used for storing the contents of the file.
198: *
199: * @return An {@link java.io.OutputStream OutputStream} that can be used
200: * for storing the contensts of the file.
201: *
202: * @exception IOException if an error occurs.
203: */
204: OutputStream getOutputStream() throws IOException;
205:
206: }
|