extensionloader.java.svn-base

一个JAVA程序员的游戏

/*
 * ExtensionLoader.java
 *
 * Created on 23. Februar 2007, 16:27
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

package kanjitori;

import java.util.HashMap;
import java.util.Map;

/**
 *
 * @author Pirx
 */
public class ExtensionLoader<Content> implements Loader<Content> {

    private Map<String, Loader<Content>> map = new HashMap<String, Loader<Content>>();
    
    /**
     * Implements the MapLoader interface.
     * @param mapFileName the FileName of the String
     * @return the Map, or null (if no MapLoader was found for this extension)
     */
    public Content load(String fileName) {
        int index = fileName.lastIndexOf('.');
        if (index != -1) {
            String ext = fileName.substring(index + 1).toLowerCase();
            Loader<Content> loader = map.get(ext);
            if (loader != null) {
                return loader.load(fileName);
            }
        }
        return null;
    }
    
    /**
     * Registers a MapLoader to be called with the given extension.
     * @param ext The File extension
     * @param loader The MapLoader
     */
    public void register(String ext, Loader<Content> loader) {
        map.put(ext.toLowerCase(), loader);
    }
    
    /**
     * Returns the "known" extensions.
     * @return A String list of all registered extensions (in lowercase)
     */
    public String[] getRegisteredExtensions() {
        String[] extensions = new String[map.size()];
        int i = 0;
        for (String s: map.keySet()) {
            extensions[i++] = s;
        }
        return extensions;
    }
    
}