mirror of https://github.com/M66B/FairEmail.git
116 lines
3.7 KiB
Java
116 lines
3.7 KiB
Java
![]() |
/*
|
||
|
* Copyright (c) 1997, 2018 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 javax.activation;
|
||
|
|
||
|
import java.io.File;
|
||
|
import java.util.Map;
|
||
|
import java.util.WeakHashMap;
|
||
|
|
||
|
/**
|
||
|
* The FileTypeMap is an abstract class that provides a data typing
|
||
|
* interface for files. Implementations of this class will
|
||
|
* implement the getContentType methods which will derive a content
|
||
|
* type from a file name or a File object. FileTypeMaps could use any
|
||
|
* scheme to determine the data type, from examining the file extension
|
||
|
* of a file (like the MimetypesFileTypeMap) to opening the file and
|
||
|
* trying to derive its type from the contents of the file. The
|
||
|
* FileDataSource class uses the default FileTypeMap (a MimetypesFileTypeMap
|
||
|
* unless changed) to determine the content type of files.
|
||
|
*
|
||
|
* @see javax.activation.FileTypeMap
|
||
|
* @see javax.activation.FileDataSource
|
||
|
* @see javax.activation.MimetypesFileTypeMap
|
||
|
*/
|
||
|
|
||
|
public abstract class FileTypeMap {
|
||
|
|
||
|
private static FileTypeMap defaultMap = null;
|
||
|
private static Map<ClassLoader,FileTypeMap> map =
|
||
|
new WeakHashMap<ClassLoader,FileTypeMap>();
|
||
|
|
||
|
/**
|
||
|
* The default constructor.
|
||
|
*/
|
||
|
public FileTypeMap() {
|
||
|
super();
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Return the type of the file object. This method should
|
||
|
* always return a valid MIME type.
|
||
|
*
|
||
|
* @param file A file to be typed.
|
||
|
* @return The content type.
|
||
|
*/
|
||
|
abstract public String getContentType(File file);
|
||
|
|
||
|
/**
|
||
|
* Return the type of the file passed in. This method should
|
||
|
* always return a valid MIME type.
|
||
|
*
|
||
|
* @param filename the pathname of the file.
|
||
|
* @return The content type.
|
||
|
*/
|
||
|
abstract public String getContentType(String filename);
|
||
|
|
||
|
/**
|
||
|
* Sets the default FileTypeMap for the system. This instance
|
||
|
* will be returned to callers of getDefaultFileTypeMap.
|
||
|
*
|
||
|
* @param fileTypeMap The FileTypeMap.
|
||
|
* @exception SecurityException if the caller doesn't have permission
|
||
|
* to change the default
|
||
|
*/
|
||
|
public static synchronized void setDefaultFileTypeMap(FileTypeMap fileTypeMap) {
|
||
|
SecurityManager security = System.getSecurityManager();
|
||
|
if (security != null) {
|
||
|
try {
|
||
|
// if it's ok with the SecurityManager, it's ok with me...
|
||
|
security.checkSetFactory();
|
||
|
} catch (SecurityException ex) {
|
||
|
// otherwise, we also allow it if this code and the
|
||
|
// factory come from the same (non-system) class loader (e.g.,
|
||
|
// the JAF classes were loaded with the applet classes).
|
||
|
ClassLoader cl = FileTypeMap.class.getClassLoader();
|
||
|
if (cl == null || cl.getParent() == null ||
|
||
|
cl != fileTypeMap.getClass().getClassLoader())
|
||
|
throw ex;
|
||
|
}
|
||
|
}
|
||
|
// remove any per-thread-context-class-loader FileTypeMap
|
||
|
map.remove(SecuritySupport.getContextClassLoader());
|
||
|
defaultMap = fileTypeMap;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Return the default FileTypeMap for the system.
|
||
|
* If setDefaultFileTypeMap was called, return
|
||
|
* that instance, otherwise return an instance of
|
||
|
* <code>MimetypesFileTypeMap</code>.
|
||
|
*
|
||
|
* @return The default FileTypeMap
|
||
|
* @see javax.activation.FileTypeMap#setDefaultFileTypeMap
|
||
|
*/
|
||
|
public static synchronized FileTypeMap getDefaultFileTypeMap() {
|
||
|
if (defaultMap != null)
|
||
|
return defaultMap;
|
||
|
|
||
|
// fetch per-thread-context-class-loader default
|
||
|
ClassLoader tccl = SecuritySupport.getContextClassLoader();
|
||
|
FileTypeMap def = map.get(tccl);
|
||
|
if (def == null) {
|
||
|
def = new MimetypesFileTypeMap();
|
||
|
map.put(tccl, def);
|
||
|
}
|
||
|
return def;
|
||
|
}
|
||
|
}
|