packageresource.java

Wicket一个开发Java Web应用程序框架。它使得开发web应用程序变得容易而轻松。 Wicket利用一个POJO data beans组件使得它可以与任何持久层技术相结合。

					String absolutePath = scope.getResource("").toExternalForm();
					File basedir;
					URI uri;
					try
					{
						uri = new URI(absolutePath);
					}
					catch (URISyntaxException e)
					{
						throw new RuntimeException(e);
					}
					try
					{
						basedir = new File(uri);
					}
					catch (IllegalArgumentException e)
					{
						log.debug("Can't construct the uri as a file: " + absolutePath);
						// if this is thrown then the path is not really a
						// file. but could be a zip.
						String jarZipPart = uri.getSchemeSpecificPart();
						// lowercased for testing if jar/zip, but leave the real
						// filespec unchanged
						String lowerJarZipPart = jarZipPart.toLowerCase();
						int index = lowerJarZipPart.indexOf(".zip");
						if (index == -1)
						{
							index = lowerJarZipPart.indexOf(".jar");
						}
						if (index == -1)
						{
							throw e;
						}

						String filename = jarZipPart.substring(0, index + 4); // 4 =
						// len of ".jar" or ".zip"
						log.debug("trying the filename: " + filename + " to load as a zip/jar.");
						JarFile jarFile = new JarFile(filename, false);
						scanJarFile(scope, pattern, recurse, resources, packageRef, jarFile);
						return (PackageResource[])resources.toArray(new PackageResource[resources
								.size()]);
					}
					if (!basedir.isDirectory())
					{
						throw new IllegalStateException("unable to read resources from directory " +
								basedir);
					}
				}
			}
		}
		catch (IOException e)
		{
			throw new WicketRuntimeException(e);
		}

		return (PackageResource[])resources.toArray(new PackageResource[resources.size()]);
	}

	/**
	 * Gets a non-localized resource for a given set of criteria. Only one resource will be loaded
	 * for the same criteria.
	 * 
	 * @param scope
	 *            This argument will be used to get the class loader for loading the package
	 *            resource, and to determine what package it is in. Typically this is the calling
	 *            class/ the class in which you call this method
	 * @param path
	 *            The path to the resource
	 * @return The resource
	 */
	public static PackageResource get(final Class scope, final String path)
	{
		return get(scope, path, null, null);
	}

	/**
	 * Gets the resource for a given set of criteria. Only one resource will be loaded for the same
	 * criteria.
	 * 
	 * @param scope
	 *            This argument will be used to get the class loader for loading the package
	 *            resource, and to determine what package it is in. Typically this is the class in
	 *            which you call this method
	 * @param path
	 *            The path to the resource
	 * @param locale
	 *            The locale of the resource
	 * @param style
	 *            The style of the resource (see {@link org.apache.wicket.Session})
	 * @return The resource
	 */
	public static PackageResource get(final Class scope, final String path, final Locale locale,
			final String style)
	{
		final SharedResources sharedResources = Application.get().getSharedResources();
		PackageResource resource = (PackageResource)sharedResources.get(scope, path, locale, style,
				true);
		if (resource == null)
		{
			resource = new PackageResource(scope, path, locale, style);
			sharedResources.add(scope, path, locale, style, resource);
		}
		return resource;
	}

	/* removed in 2.0 */
	private static void scanJarFile(Class scope, Pattern pattern, boolean recurse,
			final List resources, String packageRef, JarFile jf)
	{
		Enumeration enumeration = jf.entries();
		while (enumeration.hasMoreElements())
		{
			JarEntry je = (JarEntry)enumeration.nextElement();
			String name = je.getName();
			if (name.startsWith(packageRef))
			{
				name = name.substring(packageRef.length() + 1);
				if (pattern.matcher(name).matches() && (recurse || (name.indexOf('/') == -1)))
				{
					// we add the entry as a package resource
					resources.add(get(scope, name, null, null));
				}
			}
		}
	}

	/** The path to the resource */
	private final String absolutePath;

	/** The resource's locale */
	private Locale locale;

	/** The path this resource was created with. */
	private final String path;

	/** The scoping class, used for class loading and to determine the package. */
	private final String scopeName;

	/** The resource's style */
	private final String style;

	/**
	 * Hidden constructor.
	 * 
	 * @param scope
	 *            This argument will be used to get the class loader for loading the package
	 *            resource, and to determine what package it is in
	 * @param path
	 *            The path to the resource
	 * @param locale
	 *            The locale of the resource
	 * @param style
	 *            The style of the resource
	 */
	protected PackageResource(final Class scope, final String path, final Locale locale,
			final String style)
	{
		// Convert resource path to absolute path relative to base package
		absolutePath = Packages.absolutePath(scope, path);

		IPackageResourceGuard guard = Application.get().getResourceSettings()
				.getPackageResourceGuard();
		if (!guard.accept(scope, path))
		{
			throw new PackageResourceBlockedException("package resource " + absolutePath +
					" may not be accessed");
		}

		scopeName = scope.getName();
		this.path = path;
		this.locale = locale;
		this.style = style;

		if (locale != null)
		{
			/*
			 * Get the resource stream so that the real locale that could be resolved is set.
			 * Silently ignore not resolvable resources as we are not serving the resource for now
			 */
			getResourceStream(false);

			// Invalidate it again so that it won't hold up resources
			invalidate();
		}
	}

	/**
	 * Gets the absolute path of the resource.
	 * 
	 * @return the absolute resource path
	 */
	public final String getAbsolutePath()
	{
		return absolutePath;
	}

	/**
	 * Gets the locale.
	 * 
	 * @return The Locale of this package resource
	 */
	public final Locale getLocale()
	{
		return locale;
	}

	/**
	 * Gets the path this resource was created with.
	 * 
	 * @return the path
	 */
	public final String getPath()
	{
		return path;
	}

	/**
	 * @return Gets the resource for the component.
	 */
	public IResourceStream getResourceStream()
	{
		return getResourceStream(true);
	}

	/**
	 * @return Gets the resource for the component.
	 * @param failOnError
	 *            throw an AbortException when resource does not exist
	 */
	public IResourceStream getResourceStream(boolean failOnError)
	{
		// Locate resource
		IResourceStream resourceStream = Application.get().getResourceSettings()
				.getResourceStreamLocator().locate(getScope(), absolutePath, style, locale, null);

		// Check that resource was found
		if (resourceStream == null)
		{
			if (!failOnError)
			{
				// Do not abort the request, as we are not yet serving the resource
				return null;
			}

			String msg = "Unable to find package resource [path = " + absolutePath + ", style = " +
					style + ", locale = " + locale + "]";
			log.warn(msg);
			if (RequestCycle.get() instanceof WebRequestCycle)
			{
				throw new AbortWithWebErrorCodeException(HttpServletResponse.SC_NOT_FOUND, msg);
			}
			else
			{
				throw new AbortException();
			}
		}

		locale = resourceStream.getLocale();

		if (resourceStream != null)
		{
			lastModifiedTime = resourceStream.lastModifiedTime();
			lastModifiedTimeUpdate = System.currentTimeMillis();
		}

		return resourceStream;
	}

	/**
	 * Gets the scoping class, used for class loading and to determine the package.
	 * 
	 * @return the scoping class
	 */
	public final Class getScope()
	{
		return Classes.resolveClass(scopeName);
	}

	/**
	 * Gets the style.
	 * 
	 * @return the style
	 */
	public final String getStyle()
	{
		return style;
	}

	private transient Time lastModifiedTime = null;
	private transient long lastModifiedTimeUpdate = 0;

	/**
	 * Returns the last modified time of resource
	 * 
	 * @return last modified time or null if the time can not be determined
	 */
	public Time lastModifiedTime()
	{
		if (lastModifiedTimeUpdate == 0 ||
				lastModifiedTimeUpdate < System.currentTimeMillis() - 5 * (1000 * 60))
		{
			lastModifiedTime = getResourceStream().lastModifiedTime();
			lastModifiedTimeUpdate = System.currentTimeMillis();
		}
		return lastModifiedTime;

	}
}