jakarta.activation.FileDataSource Maven / Gradle / Ivy
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/*
* Copyright (c) 1997, 2021 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0, which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
package jakarta.activation;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
/**
* The FileDataSource class implements a simple DataSource object
* that encapsulates a file. It provides data typing services via
* a FileTypeMap object.
*
* FileDataSource Typing Semantics
*
* The FileDataSource class delegates data typing of files
* to an object subclassed from the FileTypeMap class.
* The setFileTypeMap method can be used to explicitly
* set the FileTypeMap for an instance of FileDataSource. If no
* FileTypeMap is set, the FileDataSource will call the FileTypeMap's
* getDefaultFileTypeMap method to get the System's default FileTypeMap.
*
* @see jakarta.activation.DataSource
* @see jakarta.activation.FileTypeMap
* @see jakarta.activation.MimetypesFileTypeMap
*/
public class FileDataSource implements DataSource {
// keep track of original 'ref' passed in, non-null
// one indicated which was passed in:
private File _file = null;
private FileTypeMap typeMap = null;
/**
* Creates a FileDataSource from a File object. Note:
* The file will not actually be opened until a method is
* called that requires the file to be opened.
*
* @param file the file
*/
public FileDataSource(File file) {
_file = file; // save the file Object...
}
/**
* Creates a FileDataSource from
* the specified path name. Note:
* The file will not actually be opened until a method is
* called that requires the file to be opened.
*
* @param name the system-dependent file name.
*/
public FileDataSource(String name) {
this(new File(name)); // use the file constructor
}
/**
* This method will return an InputStream representing the
* the data and will throw an IOException if it can
* not do so. This method will return a new
* instance of InputStream with each invocation.
*
* @return an InputStream
*/
public InputStream getInputStream() throws IOException {
return new FileInputStream(_file);
}
/**
* This method will return an OutputStream representing the
* the data and will throw an IOException if it can
* not do so. This method will return a new instance of
* OutputStream with each invocation.
*
* @return an OutputStream
*/
public OutputStream getOutputStream() throws IOException {
return new FileOutputStream(_file);
}
/**
* This method returns the MIME type of the data in the form of a
* string. This method uses the currently installed FileTypeMap. If
* there is no FileTypeMap explictly set, the FileDataSource will
* call the getDefaultFileTypeMap method on
* FileTypeMap to acquire a default FileTypeMap. Note: By
* default, the FileTypeMap used will be a MimetypesFileTypeMap.
*
* @return the MIME Type
* @see jakarta.activation.FileTypeMap#getDefaultFileTypeMap
*/
public String getContentType() {
// check to see if the type map is null?
if (typeMap == null)
return FileTypeMap.getDefaultFileTypeMap().getContentType(_file);
else
return typeMap.getContentType(_file);
}
/**
* Return the name of this object. The FileDataSource
* will return the file name of the object.
*
* @return the name of the object.
* @see jakarta.activation.DataSource
*/
public String getName() {
return _file.getName();
}
/**
* Return the File object that corresponds to this FileDataSource.
* @return the File object for the file represented by this object.
*/
public File getFile() {
return _file;
}
/**
* Set the FileTypeMap to use with this FileDataSource
*
* @param map The FileTypeMap for this object.
*/
public void setFileTypeMap(FileTypeMap map) {
typeMap = map;
}
}