org.omnifaces.resourcehandler.CombinedResourceInfo Maven / Gradle / Ivy
/*
* Copyright 2012 OmniFaces.
*
* 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 org.omnifaces.resourcehandler;
import static org.omnifaces.util.FacesLocal.getRequestDomainURL;
import static org.omnifaces.util.Utils.isEmpty;
import static org.omnifaces.util.Utils.serializeURLSafe;
import static org.omnifaces.util.Utils.unserializeURLSafe;
import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.faces.application.Resource;
import javax.faces.application.ResourceHandler;
import javax.faces.context.FacesContext;
import org.omnifaces.el.functions.Converters;
import org.omnifaces.util.Utils;
/**
*
* This class is a wrapper which collects all combined resources and stores it in the cache. A builder has been provided
* to create an instance of combined resource info and put it in the cache if absent.
*
* @author Bauke Scholtz
*/
public final class CombinedResourceInfo {
// Constants ------------------------------------------------------------------------------------------------------
private static final Logger logger = Logger.getLogger(CombinedResourceHandler.class.getName());
private static final Map CACHE = new ConcurrentHashMap();
private static final String LOG_RESOURCE_NOT_FOUND = "CombinedResourceHandler: The resource %s cannot be found"
+ " and therefore a 404 will be returned for the combined resource ID %s";
// Properties -----------------------------------------------------------------------------------------------------
private String id;
private Set resourceIdentifiers;
private Set resources;
private int contentLength;
private long lastModified;
// Constructors ---------------------------------------------------------------------------------------------------
/**
* Creates an instance of combined resource info based on the given ID and ordered set of resource identifiers.
* @param resourceIdentifiers Ordered set of resource identifiers, which are to be combined in a single resource.
*/
private CombinedResourceInfo(String id, Set resourceIdentifiers) {
this.id = id;
this.resourceIdentifiers = resourceIdentifiers;
}
/**
* Use this builder to create an instance of combined resource info and put it in the cache if absent.
* @author Bauke Scholtz
*/
public static final class Builder {
// Constants --------------------------------------------------------------------------------------------------
private static final String ERROR_EMPTY_RESOURCES =
"There are no resources been added. Use add() method to add them or use isEmpty() to check beforehand.";
// Properties -------------------------------------------------------------------------------------------------
private Set resourceIdentifiers = new LinkedHashSet();
// Actions ----------------------------------------------------------------------------------------------------
/**
* Add the resource represented by the given resource identifier resources of this combined resource info. The
* insertion order is maintained and duplicates are filtered.
* @param resourceIdentifier The resource identifier of the resource to be added.
* @return This builder.
*/
public Builder add(ResourceIdentifier resourceIdentifier) {
resourceIdentifiers.add(resourceIdentifier);
return this;
}
/**
* Returns true if there are no resources been added. Use this method before {@link #create()} if it's unknown
* if there are any resources been added.
* @return True if there are no resources been added, otherwise false.
*/
public boolean isEmpty() {
return resourceIdentifiers.isEmpty();
}
/**
* Creates the CombinedResourceInfo instance in cache if absent and return its ID.
* @return The ID of the CombinedResourceInfo instance.
* @throws IllegalStateException If there are no resources been added. So, to prevent it beforehand, use
* the {@link #isEmpty()} method to check if there are any resources been added.
*/
public String create() {
if (resourceIdentifiers.isEmpty()) {
throw new IllegalStateException(ERROR_EMPTY_RESOURCES);
}
return get(toUniqueId(resourceIdentifiers)).id;
}
}
/**
* Returns the combined resource info identified by the given ID from the cache. A new one will be created based on
* the given ID if absent in cache.
* @param id The ID of the combined resource info to be returned from the cache.
* @return The combined resource info identified by the given ID from the cache.
*/
public static CombinedResourceInfo get(String id) {
CombinedResourceInfo info = CACHE.get(id);
if (info == null) {
Set resourceIdentifiers = fromUniqueId(id);
if (resourceIdentifiers != null) {
info = new CombinedResourceInfo(id, Collections.unmodifiableSet(resourceIdentifiers));
CACHE.put(id, info);
}
}
return info;
}
// Actions --------------------------------------------------------------------------------------------------------
/**
* Lazily load the combined resources so that the set of resources, the total content length and the last modified
* are been initialized. If one of the resources cannot be resolved, then this will log a WARNING and leave the
* resources empty.
*/
private synchronized void loadResources() {
if (!isEmpty(resources)) {
return;
}
FacesContext context = FacesContext.getCurrentInstance();
ResourceHandler handler = context.getApplication().getResourceHandler();
resources = new LinkedHashSet();
contentLength = 0;
lastModified = 0;
for (ResourceIdentifier resourceIdentifier : resourceIdentifiers) {
Resource resource = handler.createResource(resourceIdentifier.getName(), resourceIdentifier.getLibrary());
if (resource == null) {
logger.log(Level.WARNING, String.format(LOG_RESOURCE_NOT_FOUND, resourceIdentifier, id));
resources.clear();
return;
}
resources.add(resource);
URLConnection connection;
try {
connection = resource.getURL().openConnection();
}
catch (Exception richFacesDoesNotSupportThis) {
try {
connection = new URL(getRequestDomainURL(context) + resource.getRequestPath()).openConnection();
}
catch (IOException ignore) {
// Can't and shouldn't handle it at this point.
// It would be thrown during resource streaming anyway which is a better moment.
return;
}
}
contentLength += connection.getContentLength();
long resourceLastModified = connection.getLastModified();
if (resourceLastModified > lastModified) {
lastModified = resourceLastModified;
}
}
}
/**
* Returns true if the given object is also an instance of {@link CombinedResourceInfo} and its ID equals to the
* ID of the current combined resource info instance.
*/
@Override
public boolean equals(Object other) {
return (other instanceof CombinedResourceInfo)
? ((CombinedResourceInfo) other).id.equals(id)
: false;
}
/**
* Returns the sum of the hash code of this class and the ID.
*/
@Override
public int hashCode() {
return getClass().hashCode() + id.hashCode();
}
/**
* Returns the string representation of this combined resource info in the format of
* CombinedResourceInfo[id,resourceIdentifiers]
* Where id is the unique ID and resourceIdentifiers is the ordered set of all resource
* identifiers as is been created with the builder.
*/
@Override
public String toString() {
return String.format("CombinedResourceInfo[%s,%s]", id, resourceIdentifiers);
}
// Getters --------------------------------------------------------------------------------------------------------
/**
* Returns the ordered set of resource identifiers of this combined resource info.
* @return the ordered set of resource identifiers of this combined resource info.
*/
public Set getResourceIdentifiers() {
return resourceIdentifiers;
}
/**
* Returns the ordered set of resources of this combined resource info.
* @return The ordered set of resources of this combined resource info.
*/
public Set getResources() {
loadResources();
return resources;
}
/**
* Returns the content length in bytes of this combined resource info.
* @return The content length in bytes of this combined resource info.
*/
public int getContentLength() {
loadResources();
return contentLength;
}
/**
* Returns the last modified timestamp in milliseconds of this combined resource info.
* @return The last modified timestamp in milliseconds of this combined resource info.
*/
public long getLastModified() {
loadResources();
return lastModified;
}
// Helpers ----------------------------------------------------------------------------------------------------
/**
* Create an unique ID based on the given set of resource identifiers. The current implementation converts the
* set to a |-delimited string which is serialized using {@link Utils#serialize(String)}.
* @param resourceIdentifiers The set of resource identifiers to create an unique ID for.
* @return The unique ID of the given set of resource identifiers.
*/
private static String toUniqueId(Set resourceIdentifiers) {
return serializeURLSafe(Converters.joinCollection(resourceIdentifiers, "|"));
}
/**
* Create an ordered set of resource identifiers based on the given unique ID. This does the reverse of
* {@link #toUniqueId(Map)}.
* @param id The unique ID of the set of resource identifiers.
* @return The set of resource identifiers based on the given unique ID, or null if the ID is not
* valid.
*/
private static Set fromUniqueId(String id) {
String resourcesId;
try {
resourcesId = unserializeURLSafe(id);
}
catch (IllegalArgumentException e) {
// This will occur when the ID has purposefully been manipulated for some reason.
// Just return null then so that it will end up in a 404.
return null;
}
Set resourceIdentifiers = new LinkedHashSet();
for (String resourceIdentifier : resourcesId.split("\\|")) {
resourceIdentifiers.add(new ResourceIdentifier(resourceIdentifier));
}
return resourceIdentifiers;
}
}