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.fileupload2.core; 18 19 import java.io.IOException; 20 import java.io.InputStream; 21 import java.io.OutputStream; 22 import java.io.UncheckedIOException; 23 import java.nio.charset.Charset; 24 import java.nio.file.InvalidPathException; 25 import java.nio.file.Path; 26 27 /** 28 * <p> 29 * This class represents a file or form item that was received within a {@code multipart/form-data} POST request. 30 * </p> 31 * <p> 32 * After retrieving an instance of this class from a {@link AbstractFileUpload FileUpload} instance (see 33 * {@code org.apache.commons.fileupload2.core.servlet.ServletFileUpload #parseRequest(javax.servlet.http.HttpServletRequest)}), you may either request all 34 * contents of the file at once using {@link #get()} or request an {@link InputStream} with {@link #getInputStream()} and process the file without attempting to 35 * load it into memory, which may come handy with large files. 36 * </p> 37 * <p> 38 * While this interface does not extend {@code javax.activation.DataSource} (to avoid a seldom used dependency), several of the defined methods are specifically 39 * defined with the same signatures as methods in that interface. This allows an implementation of this interface to also implement 40 * {@code javax.activation.DataSource} with minimal additional work. 41 * </p> 42 * 43 * @param <F> The FileItem type. 44 */ 45 public interface FileItem<F extends FileItem<F>> extends FileItemHeadersProvider<F> { 46 47 /** 48 * Deletes the underlying storage for a file item, including deleting any associated temporary disk file. Use this method to ensure that this is done at an 49 * earlier time, to preserve resources. 50 * 51 * @return this 52 * @throws IOException if an error occurs. 53 */ 54 F delete() throws IOException; 55 56 /** 57 * Gets the contents of the file item as a byte array. 58 * 59 * @return The contents of the file item as a byte array. 60 * 61 * @throws UncheckedIOException if an I/O error occurs 62 */ 63 byte[] get() throws UncheckedIOException; 64 65 /** 66 * Gets the content type passed by the browser or {@code null} if not defined. 67 * 68 * @return The content type passed by the browser or {@code null} if not defined. 69 */ 70 String getContentType(); 71 72 /** 73 * Gets the name of the field in the multipart form corresponding to this file item. 74 * 75 * @return The name of the form field. 76 */ 77 String getFieldName(); 78 79 /** 80 * Gets an {@link java.io.InputStream InputStream} that can be used to retrieve the contents of the file. 81 * 82 * @return An {@link java.io.InputStream InputStream} that can be used to retrieve the contents of the file. 83 * 84 * @throws IOException if an error occurs. 85 */ 86 InputStream getInputStream() throws IOException; 87 88 /** 89 * Gets the original file name in the client's file system, as provided by the browser (or other client software). In most cases, this will be the base file 90 * name, without path information. However, some clients, such as the Opera browser, do include path information. 91 * 92 * @return The original file name in the client's file system. 93 * @throws InvalidPathException The file name contains a NUL character, which might be an indicator of a security attack. If you intend to use the file name 94 * anyways, catch the exception and use InvalidFileNameException#getName(). 95 */ 96 String getName(); 97 98 /** 99 * Gets an {@link java.io.OutputStream OutputStream} that can be used for storing the contents of the file. 100 * 101 * @return An {@link java.io.OutputStream OutputStream} that can be used for storing the contents of the file. 102 * 103 * @throws IOException if an error occurs. 104 */ 105 OutputStream getOutputStream() throws IOException; 106 107 /** 108 * Gets the size of the file item. 109 * 110 * @return The size of the file item, in bytes. 111 */ 112 long getSize(); 113 114 /** 115 * Gets the contents of the file item as a String, using the default character encoding. This method uses {@link #get()} to retrieve the contents of the 116 * item. 117 * 118 * @return The contents of the item, as a string. 119 */ 120 String getString(); 121 122 /** 123 * Gets the contents of the file item as a String, using the specified encoding. This method uses {@link #get()} to retrieve the contents of the item. 124 * 125 * @param toCharset The character encoding to use. 126 * 127 * @return The contents of the item, as a string. 128 * 129 * @throws IOException if an I/O error occurs 130 */ 131 String getString(Charset toCharset) throws IOException; 132 133 /** 134 * Tests whether or not a {@code FileItem} instance represents a simple form field. 135 * 136 * @return {@code true} if the instance represents a simple form field; {@code false} if it represents an uploaded file. 137 */ 138 boolean isFormField(); 139 140 /** 141 * Tests a hint as to whether or not the file contents will be read from memory. 142 * 143 * @return {@code true} if the file contents will be read from memory; {@code false} otherwise. 144 */ 145 boolean isInMemory(); 146 147 /** 148 * Sets the field name used to reference this file item. 149 * 150 * @param name The name of the form field. 151 * @return this 152 */ 153 F setFieldName(String name); 154 155 /** 156 * Sets whether or not a {@code FileItem} instance represents a simple form field. 157 * 158 * @param state {@code true} if the instance represents a simple form field; {@code false} if it represents an uploaded file. 159 * @return this 160 */ 161 F setFormField(boolean state); 162 163 /** 164 * Writes an uploaded item to disk. 165 * <p> 166 * The client code is not concerned with whether or not the item is stored in memory, or on disk in a temporary location. They just want to write the 167 * uploaded item to a file. 168 * </p> 169 * <p> 170 * This method is not guaranteed to succeed if called more than once for the same item. This allows a particular implementation to use, for example, file 171 * renaming, where possible, rather than copying all of the underlying data, thus gaining a significant performance benefit. 172 * </p> 173 * 174 * @param file The {@code File} into which the uploaded item should be stored. 175 * @throws IOException if an error occurs. 176 * @return this 177 */ 178 F write(Path file) throws IOException; 179 180 }