org.springframework.core.io.FileSystemResource Maven / Gradle / Ivy
/*
* Copyright 2002-2018 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.core.io;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URI;
import java.net.URL;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.nio.file.FileSystem;
import java.nio.file.Files;
import java.nio.file.NoSuchFileException;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
/**
* {@link Resource} implementation for {@code java.io.File} and
* {@code java.nio.file.Path} handles with a file system target.
* Supports resolution as a {@code File} and also as a {@code URL}.
* Implements the extended {@link WritableResource} interface.
*
* Note: As of Spring Framework 5.0, this {@link Resource} implementation uses
* NIO.2 API for read/write interactions. As of 5.1, it may be constructed with a
* {@link java.nio.file.Path} handle in which case it will perform all file system
* interactions via NIO.2, only resorting to {@link File} on {@link #getFile()}.
*
* @author Juergen Hoeller
* @since 28.12.2003
* @see #FileSystemResource(File)
* @see #FileSystemResource(Path)
* @see java.io.File
* @see java.nio.file.Files
*/
public class FileSystemResource extends AbstractResource implements WritableResource {
private final String path;
@Nullable
private final File file;
private final Path filePath;
/**
* Create a new {@code FileSystemResource} from a file path.
*
Note: When building relative resources via {@link #createRelative},
* it makes a difference whether the specified resource base path here
* ends with a slash or not. In the case of "C:/dir1/", relative paths
* will be built underneath that root: e.g. relative path "dir2" ->
* "C:/dir1/dir2". In the case of "C:/dir1", relative paths will apply
* at the same directory level: relative path "dir2" -> "C:/dir2".
* @param path a file path
* @see #FileSystemResource(Path)
*/
public FileSystemResource(String path) {
Assert.notNull(path, "Path must not be null");
this.path = StringUtils.cleanPath(path);
this.file = new File(path);
this.filePath = this.file.toPath();
}
/**
* Create a new {@code FileSystemResource} from a {@link File} handle.
*
Note: When building relative resources via {@link #createRelative},
* the relative path will apply at the same directory level:
* e.g. new File("C:/dir1"), relative path "dir2" -> "C:/dir2"!
* If you prefer to have relative paths built underneath the given root directory,
* use the {@link #FileSystemResource(String) constructor with a file path}
* to append a trailing slash to the root path: "C:/dir1/", which indicates
* this directory as root for all relative paths.
* @param file a File handle
* @see #FileSystemResource(Path)
* @see #getFile()
*/
public FileSystemResource(File file) {
Assert.notNull(file, "File must not be null");
this.path = StringUtils.cleanPath(file.getPath());
this.file = file;
this.filePath = file.toPath();
}
/**
* Create a new {@code FileSystemResource} from a {@link Path} handle,
* performing all file system interactions via NIO.2 instead of {@link File}.
*
In contrast to {@link PathResource}, this variant strictly follows the
* general {@link FileSystemResource} conventions, in particular in terms of
* path cleaning and {@link #createRelative(String)} handling.
* @param filePath a Path handle to a file
* @since 5.1
* @see #FileSystemResource(File)
*/
public FileSystemResource(Path filePath) {
Assert.notNull(filePath, "Path must not be null");
this.path = StringUtils.cleanPath(filePath.toString());
this.file = null;
this.filePath = filePath;
}
/**
* Create a new {@code FileSystemResource} from a {@link FileSystem} handle,
* locating the specified path.
*
This is an alternative to {@link #FileSystemResource(String)},
* performing all file system interactions via NIO.2 instead of {@link File}.
* @param fileSystem the FileSystem to locate the path within
* @param path a file path
* @since 5.1.1
* @see #FileSystemResource(File)
*/
public FileSystemResource(FileSystem fileSystem, String path) {
Assert.notNull(fileSystem, "FileSystem must not be null");
Assert.notNull(path, "Path must not be null");
this.path = StringUtils.cleanPath(path);
this.file = null;
this.filePath = fileSystem.getPath(this.path).normalize();
}
/**
* Return the file path for this resource.
*/
public final String getPath() {
return this.path;
}
/**
* This implementation returns whether the underlying file exists.
* @see java.io.File#exists()
*/
@Override
public boolean exists() {
return (this.file != null ? this.file.exists() : Files.exists(this.filePath));
}
/**
* This implementation checks whether the underlying file is marked as readable
* (and corresponds to an actual file with content, not to a directory).
* @see java.io.File#canRead()
* @see java.io.File#isDirectory()
*/
@Override
public boolean isReadable() {
return (this.file != null ? this.file.canRead() && !this.file.isDirectory() :
Files.isReadable(this.filePath) && !Files.isDirectory(this.filePath));
}
/**
* This implementation opens a NIO file stream for the underlying file.
* @see java.io.FileInputStream
*/
@Override
public InputStream getInputStream() throws IOException {
try {
return Files.newInputStream(this.filePath);
}
catch (NoSuchFileException ex) {
throw new FileNotFoundException(ex.getMessage());
}
}
/**
* This implementation checks whether the underlying file is marked as writable
* (and corresponds to an actual file with content, not to a directory).
* @see java.io.File#canWrite()
* @see java.io.File#isDirectory()
*/
@Override
public boolean isWritable() {
return (this.file != null ? this.file.canWrite() && !this.file.isDirectory() :
Files.isWritable(this.filePath) && !Files.isDirectory(this.filePath));
}
/**
* This implementation opens a FileOutputStream for the underlying file.
* @see java.io.FileOutputStream
*/
@Override
public OutputStream getOutputStream() throws IOException {
return Files.newOutputStream(this.filePath);
}
/**
* This implementation returns a URL for the underlying file.
* @see java.io.File#toURI()
*/
@Override
public URL getURL() throws IOException {
return (this.file != null ? this.file.toURI().toURL() : this.filePath.toUri().toURL());
}
/**
* This implementation returns a URI for the underlying file.
* @see java.io.File#toURI()
*/
@Override
public URI getURI() throws IOException {
return (this.file != null ? this.file.toURI() : this.filePath.toUri());
}
/**
* This implementation always indicates a file.
*/
@Override
public boolean isFile() {
return true;
}
/**
* This implementation returns the underlying File reference.
*/
@Override
public File getFile() {
return (this.file != null ? this.file : this.filePath.toFile());
}
/**
* This implementation opens a FileChannel for the underlying file.
* @see java.nio.channels.FileChannel
*/
@Override
public ReadableByteChannel readableChannel() throws IOException {
try {
return FileChannel.open(this.filePath, StandardOpenOption.READ);
}
catch (NoSuchFileException ex) {
throw new FileNotFoundException(ex.getMessage());
}
}
/**
* This implementation opens a FileChannel for the underlying file.
* @see java.nio.channels.FileChannel
*/
@Override
public WritableByteChannel writableChannel() throws IOException {
return FileChannel.open(this.filePath, StandardOpenOption.WRITE);
}
/**
* This implementation returns the underlying File/Path length.
*/
@Override
public long contentLength() throws IOException {
if (this.file != null) {
long length = this.file.length();
if (length == 0L && !this.file.exists()) {
throw new FileNotFoundException(getDescription() +
" cannot be resolved in the file system for checking its content length");
}
return length;
}
else {
try {
return Files.size(this.filePath);
}
catch (NoSuchFileException ex) {
throw new FileNotFoundException(ex.getMessage());
}
}
}
/**
* This implementation returns the underlying File/Path last-modified time.
*/
@Override
public long lastModified() throws IOException {
if (this.file != null) {
return super.lastModified();
}
else {
try {
return Files.getLastModifiedTime(this.filePath).toMillis();
}
catch (NoSuchFileException ex) {
throw new FileNotFoundException(ex.getMessage());
}
}
}
/**
* This implementation creates a FileSystemResource, applying the given path
* relative to the path of the underlying file of this resource descriptor.
* @see org.springframework.util.StringUtils#applyRelativePath(String, String)
*/
@Override
public Resource createRelative(String relativePath) {
String pathToUse = StringUtils.applyRelativePath(this.path, relativePath);
return (this.file != null ? new FileSystemResource(pathToUse) :
new FileSystemResource(this.filePath.getFileSystem(), pathToUse));
}
/**
* This implementation returns the name of the file.
* @see java.io.File#getName()
*/
@Override
public String getFilename() {
return (this.file != null ? this.file.getName() : this.filePath.getFileName().toString());
}
/**
* This implementation returns a description that includes the absolute
* path of the file.
* @see java.io.File#getAbsolutePath()
*/
@Override
public String getDescription() {
return "file [" + (this.file != null ? this.file.getAbsolutePath() : this.filePath.toAbsolutePath()) + "]";
}
/**
* This implementation compares the underlying File references.
*/
@Override
public boolean equals(Object other) {
return (this == other || (other instanceof FileSystemResource &&
this.path.equals(((FileSystemResource) other).path)));
}
/**
* This implementation returns the hash code of the underlying File reference.
*/
@Override
public int hashCode() {
return this.path.hashCode();
}
}