public FileTypeMap() 
{
        super();
}

The default constructor.

 abstract public String getContentType(File file)
Return the type of the file object. This method should
always return a valid MIME type.

 abstract public String getContentType(String filename)
Return the type of the file passed in.  This method should
always return a valid MIME type.

 public static FileTypeMap getDefaultFileTypeMap() 
{
        // XXX - probably should be synchronized
        if (defaultMap == null)
            defaultMap = new MimetypesFileTypeMap();
        return defaultMap;
}

Return the default FileTypeMap for the system. If setDefaultFileTypeMap was called, return that instance, otherwise return an instance of MimetypesFileTypeMap.

 public static  void setDefaultFileTypeMap(FileTypeMap map) 
{
        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 class loader (e.g.,
                // the JAF classes were loaded with the applet classes).
                if (FileTypeMap.class.getClassLoader() !=
                        map.getClass().getClassLoader())
                    throw ex;
            }
        }
        defaultMap = map;
}

Sets the default FileTypeMap for the system. This instance will be returned to callers of getDefaultFileTypeMap.