https://openjdk.java.net/ 
/*
 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.activation;

import java.io.InputStream;
import java.io.OutputStream;
import java.io.File;
import java.io.FileDescriptor;
import java.io.FileNotFoundException;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import com.sun.activation.registries.MimeTypeFile;


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 Also:
Since:1.6
/**
 * The FileDataSource class implements a simple DataSource object
 * that encapsulates a file. It provides data typing services via
 * a FileTypeMap object. <p>
 *
 * <b>FileDataSource Typing Semantics</b><p>
 *
 * The FileDataSource class delegates data typing of files
 * to an object subclassed from the FileTypeMap class.
 * The <code>setFileTypeMap</code> 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 javax.activation.DataSource
 * @see javax.activation.FileTypeMap
 * @see javax.activation.MimetypesFileTypeMap
 *
 * @since 1.6
 */
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.

Params:
  • file – the file
/**
     * Creates a FileDataSource from a File object. <i>Note:
     * The file will not actually be opened until a method is
     * called that requires the file to be opened.</i>
     *
     * @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.

Params:
  • name – the system-dependent file name.
/**
     * Creates a FileDataSource from
     * the specified path name. <i>Note:
     * The file will not actually be opened until a method is
     * called that requires the file to be opened.</i>
     *
     * @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.

Returns:an InputStream
/**
     * 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.

Returns:an OutputStream
/**
     * 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.

See Also:
Returns:the MIME Type
/**
     * 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 <code>getDefaultFileTypeMap</code> method on
     * FileTypeMap to acquire a default FileTypeMap. <i>Note: By
     * default, the FileTypeMap used will be a MimetypesFileTypeMap.</i>
     *
     * @return the MIME Type
     * @see javax.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.

See Also:
Returns:the name of the object.
/**
     * Return the <i>name</i> of this object. The FileDataSource
     * will return the file name of the object.
     *
     * @return the name of the object.
     * @see javax.activation.DataSource
     */
    public String getName() {
        return _file.getName();
    }

    
Return the File object that corresponds to this FileDataSource.

Returns:the File object for the file represented by this object.
/**
     * 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

Params:
  • map – The FileTypeMap for this object.
/**
     * Set the FileTypeMap to use with this FileDataSource
     *
     * @param map The FileTypeMap for this object.
     */
    public void setFileTypeMap(FileTypeMap map) {
        typeMap = map;
    }
}