com.firefly.utils.io.FileSystemResource Maven / Gradle / Ivy
package com.firefly.utils.io;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URI;
import java.net.URL;
import com.firefly.utils.Assert;
import com.firefly.utils.StringUtils;
/**
* {@link Resource} implementation for {@code java.io.File} handles.
* Obviously supports resolution as File, and also as URL.
* Implements the extended {@link WritableResource} interface.
* @see java.io.File
*/
public class FileSystemResource extends AbstractResource implements WritableResource {
private final File file;
private final String path;
/**
* 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
*/
public FileSystemResource(File file) {
Assert.notNull(file, "File must not be null");
this.file = file;
this.path = StringUtils.cleanPath(file.getPath());
}
/**
* 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
*/
public FileSystemResource(String path) {
Assert.notNull(path, "Path must not be null");
this.file = new File(path);
this.path = StringUtils.cleanPath(path);
}
/**
* 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.exists();
}
/**
* 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.canRead() && !this.file.isDirectory());
}
/**
* This implementation opens a FileInputStream for the underlying file.
* @see java.io.FileInputStream
*/
@Override
public InputStream getInputStream() throws IOException {
return new FileInputStream(this.file);
}
/**
* 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.canWrite() && !this.file.isDirectory());
}
/**
* This implementation opens a FileOutputStream for the underlying file.
* @see java.io.FileOutputStream
*/
@Override
public OutputStream getOutputStream() throws IOException {
return new FileOutputStream(this.file);
}
/**
* This implementation returns a URL for the underlying file.
* @see java.io.File#toURI()
*/
@Override
public URL getURL() throws IOException {
return this.file.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.toURI();
}
/**
* This implementation returns the underlying File reference.
*/
@Override
public File getFile() {
return this.file;
}
/**
* This implementation returns the underlying File's length.
*/
@Override
public long contentLength() throws IOException {
return this.file.length();
}
/**
* This implementation creates a FileSystemResource, applying the given path
* relative to the path of the underlying file of this resource descriptor.
*/
@Override
public Resource createRelative(String relativePath) {
String pathToUse = StringUtils.applyRelativePath(this.path, relativePath);
return new FileSystemResource(pathToUse);
}
/**
* This implementation returns the name of the file.
* @see java.io.File#getName()
*/
@Override
public String getFilename() {
return this.file.getName();
}
/**
* 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.getAbsolutePath() + "]";
}
/**
* This implementation compares the underlying File references.
*/
@Override
public boolean equals(Object obj) {
return (obj == this ||
(obj instanceof FileSystemResource && this.path.equals(((FileSystemResource) obj).path)));
}
/**
* This implementation returns the hash code of the underlying File reference.
*/
@Override
public int hashCode() {
return this.path.hashCode();
}
}