xcachemanager.java

XBrowser是一个完全免费并且开源的Web浏览器

/****************************************************************
*              XBrowser  -  eXtended web Browser                *
*                                                               *
*           Copyright (c) 2000-2001  Armond Avanes              *
*     Refer to ReadMe & License files for more information      *
*                                                               *
*                                                               *
*                      By: Armond Avanes                        *
*       [e-mail]     &    [e-mail]        *
*                http://xbrowser.sourceforge.net/               *
*****************************************************************/
package xbrowser.cache;

import java.util.*;
import java.net.*;
import java.io.*;

import xbrowser.*;

public final class XCacheManager
{
	public void load()
	{
		try
		{
		String file_name = XProjectConstants.CONFIG_DIR+XRepository.getConfiguration().getCacheIndexFileName();

			XRepository.getConfiguration().getActiveCacheIndexSerializer().getSerializer().importCacheIndexes(file_name, this);
		}
		catch( Exception e )
		{
			XRepository.getLogger().warning(this, "An error occured on loading the cache indexes!");
			XRepository.getLogger().warning(this, e);

			clearCache();
			//save();
		}
	}

	public void save()
	{
		try
		{
		String file_name = XProjectConstants.CONFIG_DIR+XRepository.getConfiguration().getCacheIndexFileName();

			XRepository.getConfiguration().getActiveCacheIndexSerializer().getSerializer().exportCacheIndexes(file_name, this);
		}
		catch( Exception e )
		{
			XRepository.getLogger().warning(this, "An error occured while saving the cache indexes!");
			XRepository.getLogger().warning(this, e);
		}
	}

    public void addCacheItem(XCacheItem cache_item)
    {
		cache.put(cache_item.getURL(), cache_item);
	}

    public Iterator getCacheItems()
    {
		return cache.values().iterator();
	}

	public void clearCache()
	{
	Iterator it = getCacheItems();

		while( it.hasNext() )
			((XCacheItem)it.next()).delete();

		cache.clear();
	}

    /** Remove record about cached url. */
    public void removeFromCache(String url)
    {
	XCacheItem cache_item = (XCacheItem)cache.get(url);

		cache_item.delete();
		cache.remove(url);
		if( isCached(url))
			XRepository.getLogger().error(this, "HOW???");
	}

    /** Returns File to write resource contained in url.
     *  Will put url to cache; removeFromCache() if loading from url failed.
     */
    public File getFileToCache(String url) throws IOException
    {
        if( !isCached(url) )
        {
		File tmp = File.createTempFile("XBC", ".htm", cacheDir);
		XCacheItem cache_item = new XCacheItem();

            cache_item.setURL(url);
            cache_item.setFileName( tmp.getCanonicalPath() );

            cache.put(url, cache_item);
            return tmp;
        }
        else
            return ((XCacheItem)cache.get(url)).getFile();
    }

    /** Check for presence in cache. */
    public synchronized boolean isCached(String url)
    {
        return cache.containsKey(url);
    }

    /** Set content type for cached thing. */
    public void setContentType(String url, String content_type)
    {
	XCacheItem cache_item = (XCacheItem)cache.get(url);

        cache_item.setContentType(content_type);
    }

    /** Return saved content type for url. */
    public String getContentType(String url)
    {
        return ((XCacheItem)cache.get(url)).getContentType();
    }

// Attributes:
    private Map cache = new HashMap();

    private final static File cacheDir = new File(XProjectConstants.CACHE_DIR);
}