001/* 002 * Copyright 2002-2019 the original author or authors. 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 * https://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 017package org.springframework.core.io; 018 019import java.io.File; 020import java.io.FileNotFoundException; 021import java.io.IOException; 022import java.io.InputStream; 023import java.io.OutputStream; 024import java.net.URI; 025import java.net.URL; 026import java.nio.channels.FileChannel; 027import java.nio.channels.ReadableByteChannel; 028import java.nio.channels.WritableByteChannel; 029import java.nio.file.FileSystem; 030import java.nio.file.Files; 031import java.nio.file.NoSuchFileException; 032import java.nio.file.Path; 033import java.nio.file.StandardOpenOption; 034 035import org.springframework.lang.Nullable; 036import org.springframework.util.Assert; 037import org.springframework.util.StringUtils; 038 039/** 040 * {@link Resource} implementation for {@code java.io.File} and 041 * {@code java.nio.file.Path} handles with a file system target. 042 * Supports resolution as a {@code File} and also as a {@code URL}. 043 * Implements the extended {@link WritableResource} interface. 044 * 045 * <p>Note: As of Spring Framework 5.0, this {@link Resource} implementation uses 046 * NIO.2 API for read/write interactions. As of 5.1, it may be constructed with a 047 * {@link java.nio.file.Path} handle in which case it will perform all file system 048 * interactions via NIO.2, only resorting to {@link File} on {@link #getFile()}. 049 * 050 * @author Juergen Hoeller 051 * @since 28.12.2003 052 * @see #FileSystemResource(String) 053 * @see #FileSystemResource(File) 054 * @see #FileSystemResource(Path) 055 * @see java.io.File 056 * @see java.nio.file.Files 057 */ 058public class FileSystemResource extends AbstractResource implements WritableResource { 059 060 private final String path; 061 062 @Nullable 063 private final File file; 064 065 private final Path filePath; 066 067 068 /** 069 * Create a new {@code FileSystemResource} from a file path. 070 * <p>Note: When building relative resources via {@link #createRelative}, 071 * it makes a difference whether the specified resource base path here 072 * ends with a slash or not. In the case of "C:/dir1/", relative paths 073 * will be built underneath that root: e.g. relative path "dir2" -> 074 * "C:/dir1/dir2". In the case of "C:/dir1", relative paths will apply 075 * at the same directory level: relative path "dir2" -> "C:/dir2". 076 * @param path a file path 077 * @see #FileSystemResource(Path) 078 */ 079 public FileSystemResource(String path) { 080 Assert.notNull(path, "Path must not be null"); 081 this.path = StringUtils.cleanPath(path); 082 this.file = new File(path); 083 this.filePath = this.file.toPath(); 084 } 085 086 /** 087 * Create a new {@code FileSystemResource} from a {@link File} handle. 088 * <p>Note: When building relative resources via {@link #createRelative}, 089 * the relative path will apply <i>at the same directory level</i>: 090 * e.g. new File("C:/dir1"), relative path "dir2" -> "C:/dir2"! 091 * If you prefer to have relative paths built underneath the given root directory, 092 * use the {@link #FileSystemResource(String) constructor with a file path} 093 * to append a trailing slash to the root path: "C:/dir1/", which indicates 094 * this directory as root for all relative paths. 095 * @param file a File handle 096 * @see #FileSystemResource(Path) 097 * @see #getFile() 098 */ 099 public FileSystemResource(File file) { 100 Assert.notNull(file, "File must not be null"); 101 this.path = StringUtils.cleanPath(file.getPath()); 102 this.file = file; 103 this.filePath = file.toPath(); 104 } 105 106 /** 107 * Create a new {@code FileSystemResource} from a {@link Path} handle, 108 * performing all file system interactions via NIO.2 instead of {@link File}. 109 * <p>In contrast to {@link PathResource}, this variant strictly follows the 110 * general {@link FileSystemResource} conventions, in particular in terms of 111 * path cleaning and {@link #createRelative(String)} handling. 112 * <p>Note: When building relative resources via {@link #createRelative}, 113 * the relative path will apply <i>at the same directory level</i>: 114 * e.g. Paths.get("C:/dir1"), relative path "dir2" -> "C:/dir2"! 115 * If you prefer to have relative paths built underneath the given root directory, 116 * use the {@link #FileSystemResource(String) constructor with a file path} 117 * to append a trailing slash to the root path: "C:/dir1/", which indicates 118 * this directory as root for all relative paths. Alternatively, consider 119 * using {@link PathResource#PathResource(Path)} for {@code java.nio.path.Path} 120 * resolution in {@code createRelative}, always nesting relative paths. 121 * @param filePath a Path handle to a file 122 * @since 5.1 123 * @see #FileSystemResource(File) 124 */ 125 public FileSystemResource(Path filePath) { 126 Assert.notNull(filePath, "Path must not be null"); 127 this.path = StringUtils.cleanPath(filePath.toString()); 128 this.file = null; 129 this.filePath = filePath; 130 } 131 132 /** 133 * Create a new {@code FileSystemResource} from a {@link FileSystem} handle, 134 * locating the specified path. 135 * <p>This is an alternative to {@link #FileSystemResource(String)}, 136 * performing all file system interactions via NIO.2 instead of {@link File}. 137 * @param fileSystem the FileSystem to locate the path within 138 * @param path a file path 139 * @since 5.1.1 140 * @see #FileSystemResource(File) 141 */ 142 public FileSystemResource(FileSystem fileSystem, String path) { 143 Assert.notNull(fileSystem, "FileSystem must not be null"); 144 Assert.notNull(path, "Path must not be null"); 145 this.path = StringUtils.cleanPath(path); 146 this.file = null; 147 this.filePath = fileSystem.getPath(this.path).normalize(); 148 } 149 150 151 /** 152 * Return the file path for this resource. 153 */ 154 public final String getPath() { 155 return this.path; 156 } 157 158 /** 159 * This implementation returns whether the underlying file exists. 160 * @see java.io.File#exists() 161 */ 162 @Override 163 public boolean exists() { 164 return (this.file != null ? this.file.exists() : Files.exists(this.filePath)); 165 } 166 167 /** 168 * This implementation checks whether the underlying file is marked as readable 169 * (and corresponds to an actual file with content, not to a directory). 170 * @see java.io.File#canRead() 171 * @see java.io.File#isDirectory() 172 */ 173 @Override 174 public boolean isReadable() { 175 return (this.file != null ? this.file.canRead() && !this.file.isDirectory() : 176 Files.isReadable(this.filePath) && !Files.isDirectory(this.filePath)); 177 } 178 179 /** 180 * This implementation opens a NIO file stream for the underlying file. 181 * @see java.io.FileInputStream 182 */ 183 @Override 184 public InputStream getInputStream() throws IOException { 185 try { 186 return Files.newInputStream(this.filePath); 187 } 188 catch (NoSuchFileException ex) { 189 throw new FileNotFoundException(ex.getMessage()); 190 } 191 } 192 193 /** 194 * This implementation checks whether the underlying file is marked as writable 195 * (and corresponds to an actual file with content, not to a directory). 196 * @see java.io.File#canWrite() 197 * @see java.io.File#isDirectory() 198 */ 199 @Override 200 public boolean isWritable() { 201 return (this.file != null ? this.file.canWrite() && !this.file.isDirectory() : 202 Files.isWritable(this.filePath) && !Files.isDirectory(this.filePath)); 203 } 204 205 /** 206 * This implementation opens a FileOutputStream for the underlying file. 207 * @see java.io.FileOutputStream 208 */ 209 @Override 210 public OutputStream getOutputStream() throws IOException { 211 return Files.newOutputStream(this.filePath); 212 } 213 214 /** 215 * This implementation returns a URL for the underlying file. 216 * @see java.io.File#toURI() 217 */ 218 @Override 219 public URL getURL() throws IOException { 220 return (this.file != null ? this.file.toURI().toURL() : this.filePath.toUri().toURL()); 221 } 222 223 /** 224 * This implementation returns a URI for the underlying file. 225 * @see java.io.File#toURI() 226 */ 227 @Override 228 public URI getURI() throws IOException { 229 return (this.file != null ? this.file.toURI() : this.filePath.toUri()); 230 } 231 232 /** 233 * This implementation always indicates a file. 234 */ 235 @Override 236 public boolean isFile() { 237 return true; 238 } 239 240 /** 241 * This implementation returns the underlying File reference. 242 */ 243 @Override 244 public File getFile() { 245 return (this.file != null ? this.file : this.filePath.toFile()); 246 } 247 248 /** 249 * This implementation opens a FileChannel for the underlying file. 250 * @see java.nio.channels.FileChannel 251 */ 252 @Override 253 public ReadableByteChannel readableChannel() throws IOException { 254 try { 255 return FileChannel.open(this.filePath, StandardOpenOption.READ); 256 } 257 catch (NoSuchFileException ex) { 258 throw new FileNotFoundException(ex.getMessage()); 259 } 260 } 261 262 /** 263 * This implementation opens a FileChannel for the underlying file. 264 * @see java.nio.channels.FileChannel 265 */ 266 @Override 267 public WritableByteChannel writableChannel() throws IOException { 268 return FileChannel.open(this.filePath, StandardOpenOption.WRITE); 269 } 270 271 /** 272 * This implementation returns the underlying File/Path length. 273 */ 274 @Override 275 public long contentLength() throws IOException { 276 if (this.file != null) { 277 long length = this.file.length(); 278 if (length == 0L && !this.file.exists()) { 279 throw new FileNotFoundException(getDescription() + 280 " cannot be resolved in the file system for checking its content length"); 281 } 282 return length; 283 } 284 else { 285 try { 286 return Files.size(this.filePath); 287 } 288 catch (NoSuchFileException ex) { 289 throw new FileNotFoundException(ex.getMessage()); 290 } 291 } 292 } 293 294 /** 295 * This implementation returns the underlying File/Path last-modified time. 296 */ 297 @Override 298 public long lastModified() throws IOException { 299 if (this.file != null) { 300 return super.lastModified(); 301 } 302 else { 303 try { 304 return Files.getLastModifiedTime(this.filePath).toMillis(); 305 } 306 catch (NoSuchFileException ex) { 307 throw new FileNotFoundException(ex.getMessage()); 308 } 309 } 310 } 311 312 /** 313 * This implementation creates a FileSystemResource, applying the given path 314 * relative to the path of the underlying file of this resource descriptor. 315 * @see org.springframework.util.StringUtils#applyRelativePath(String, String) 316 */ 317 @Override 318 public Resource createRelative(String relativePath) { 319 String pathToUse = StringUtils.applyRelativePath(this.path, relativePath); 320 return (this.file != null ? new FileSystemResource(pathToUse) : 321 new FileSystemResource(this.filePath.getFileSystem(), pathToUse)); 322 } 323 324 /** 325 * This implementation returns the name of the file. 326 * @see java.io.File#getName() 327 */ 328 @Override 329 public String getFilename() { 330 return (this.file != null ? this.file.getName() : this.filePath.getFileName().toString()); 331 } 332 333 /** 334 * This implementation returns a description that includes the absolute 335 * path of the file. 336 * @see java.io.File#getAbsolutePath() 337 */ 338 @Override 339 public String getDescription() { 340 return "file [" + (this.file != null ? this.file.getAbsolutePath() : this.filePath.toAbsolutePath()) + "]"; 341 } 342 343 344 /** 345 * This implementation compares the underlying File references. 346 */ 347 @Override 348 public boolean equals(@Nullable Object other) { 349 return (this == other || (other instanceof FileSystemResource && 350 this.path.equals(((FileSystemResource) other).path))); 351 } 352 353 /** 354 * This implementation returns the hash code of the underlying File reference. 355 */ 356 @Override 357 public int hashCode() { 358 return this.path.hashCode(); 359 } 360 361}