geronimo-spec-activation/src/java/javax/activation/FileTypeMap.java

/**
 *
 * Copyright 2003-2004 The Apache Software Foundation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package javax.activation;

import java.io.File;

/**
 * FileTypeMap is an abstract class that provides a data type interface for files.
 *
 * @version $Rev$ $Date$
 */
public abstract class FileTypeMap {
    // we use null here rather than a default because
    // the constructor for MimetypesFileTypeMap does a lot of I/O
    private static FileTypeMap defaultFileTypeMap = null;

    /**
     * Sets the default FileTypeMap for the system.
     * @param fileMap the new default FileTypeMap
     * @throws SecurityException if the caller does not have "SetFactory" RuntimePermission
     */
    public static void setDefaultFileTypeMap(FileTypeMap fileMap) {
        SecurityManager sm = System.getSecurityManager();
        if (sm != null) {
            sm.checkSetFactory();
        }
        defaultFileTypeMap = fileMap;
    }

    /**
     * Returns the default FileTypeMap
     * @return the default FileTYpeMap; if null returns a MimetypesFileTypeMap
     */
    public synchronized static FileTypeMap getDefaultFileTypeMap() {
        if (defaultFileTypeMap == null) {
            defaultFileTypeMap = new MimetypesFileTypeMap();
        }
        return defaultFileTypeMap;
    }

    public FileTypeMap() {
    }

    public abstract String getContentType(File file);

    public abstract String getContentType(String filename);
}