com.sun.faces.application.resource.Resource Maven / Gradle / Ivy
Show all versions of jakarta.faces Show documentation
/*
* Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
* Copyright 2005-2007 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 com.sun.faces.application.resource;
import static java.util.logging.Level.FINE;
import static java.util.logging.Level.FINEST;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;
import java.util.Set;
import java.util.logging.Logger;
import com.sun.faces.util.FacesLogger;
import jakarta.faces.context.ExternalContext;
import jakarta.faces.context.FacesContext;
import jakarta.servlet.ServletContext;
/**
* @author Roland Huss
*
*/
public final class Resource {
protected final static Logger LOGGER = FacesLogger.FACELETS_FACTORY.getLogger();
/**
* Get an URL of an internal resource.
*
*
* First, {@link jakarta.faces.context.ExternalContext#getResource(String)} is checked for an non-null URL return value.
* In the case of a null return value (as it is the case for Weblogic 8.1 for a packed war), a URL with a special URL
* handler is constructed, which can be used for opening a servlet resource later.
*
*
* Internally, this special URL handler will call {@link ServletContext#getResourceAsStream(String)} when an inputstream
* is requested. This even works on Weblogic 8.1
*
* @param ctx the faces context from which to retrieve the resource
* @param path an URL path
*
* @return an url representing the URL and on which getInputStream() can be called to get the resource
* @throws MalformedURLException
*/
static URL getResourceUrl(FacesContext ctx, String path) throws MalformedURLException {
ExternalContext externalContext = ctx.getExternalContext();
URL url = externalContext.getResource(path);
if (LOGGER.isLoggable(FINE)) {
LOGGER.fine("Resource-Url from external context: " + url);
}
// This might happen on a Servlet container which does not return anything
// for getResource() (like weblogic 8.1 for packaged wars) we are trying
// to use an own URL protocol in order to use ServletContext.getResourceAsStream()
// when opening the url
if (url == null && resourceExist(externalContext, path)) {
url = getUrlForResourceAsStream(externalContext, path);
}
return url;
}
static Set getViewResourcePaths(FacesContext ctx, String path) {
return ctx.getExternalContext().getResourcePaths(path);
}
// This method could be used above to provide a 'fail fast' if a resource
// doesn't exist. Otherwise, the URL will fail on the first access.
private static boolean resourceExist(ExternalContext externalContext, String path) {
if ("/".equals(path)) {
// The root context exists always
return true;
}
Object ctx = externalContext.getContext();
if (ctx instanceof ServletContext) {
ServletContext servletContext = (ServletContext) ctx;
InputStream stream = servletContext.getResourceAsStream(path);
if (stream != null) {
try {
stream.close();
} catch (IOException e) {
if (LOGGER.isLoggable(FINEST)) {
LOGGER.log(FINEST, "Closing stream", e);
}
}
return true;
}
}
return false;
}
// Construct URL with special URLStreamHandler for proxying
// ServletContext.getResourceAsStream()
private static URL getUrlForResourceAsStream(final ExternalContext externalContext, String path) throws MalformedURLException {
URLStreamHandler handler = new URLStreamHandler() {
@Override
protected URLConnection openConnection(URL u) throws IOException {
final String file = u.getFile();
return new URLConnection(u) {
@Override
public void connect() throws IOException {
}
@Override
public InputStream getInputStream() throws IOException {
if (LOGGER.isLoggable(FINE)) {
LOGGER.fine("Opening internal url to " + file);
}
Object ctx = externalContext.getContext();
// Or maybe fetch the external context afresh ?
// Object ctx =
// FacesContext.getCurrentInstance().getExternalContext().getContext();
if (ctx instanceof ServletContext) {
ServletContext servletContext = (ServletContext) ctx;
InputStream stream = servletContext.getResourceAsStream(file);
if (stream == null) {
throw new FileNotFoundException("Cannot open resource " + file);
}
return stream;
} else {
throw new IOException("Cannot open resource for an context of " + (ctx != null ? ctx.getClass() : null));
}
}
};
}
};
return new URL("internal", null, 0, path, handler);
}
}