/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.wicket.markup.html;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.SoftReference;
import java.util.Locale;
import java.util.zip.GZIPOutputStream;
import org.apache.wicket.Application;
import org.apache.wicket.SharedResources;
import org.apache.wicket.markup.html.resources.CompressedResourceReference;
import org.apache.wicket.protocol.http.WebRequest;
import org.apache.wicket.protocol.http.WebRequestCycle;
import org.apache.wicket.protocol.http.WebResponse;
import org.apache.wicket.util.io.Streams;
import org.apache.wicket.util.resource.IResourceStream;
import org.apache.wicket.util.resource.ResourceStreamNotFoundException;
import org.apache.wicket.util.time.Time;
/**
* Identical to PackageResource, but supports gzip compression of data
*
* See {@link PackageResource} and {@link CompressedResourceReference}
*
* @author Janne Hietamäki
*/
public class CompressedPackageResource extends PackageResource
{
/**
* IResourceStream implementation which compresses the data with gzip if the
* requests header Accept-Encoding contains string gzip
*/
protected abstract class CompressingResourceStream implements IResourceStream
{
private static final long serialVersionUID = 1L;
/** Cache for compressed data */
private SoftReference cache = new SoftReference(null);
/** Timestamp of the cache */
private Time timeStamp = null;
/**
* @see org.apache.wicket.util.resource.IResourceStream#close()
*/
public void close() throws IOException
{
}
/**
* @see org.apache.wicket.util.resource.IResourceStream#getContentType()
*/
public String getContentType()
{
return getOriginalResourceStream().getContentType();
}
/**
* @see org.apache.wicket.util.resource.IResourceStream#getInputStream()
*/
public InputStream getInputStream() throws ResourceStreamNotFoundException
{
if (supportsCompression())
{
return new ByteArrayInputStream(getCompressedContent());
}
else
{
return getOriginalResourceStream().getInputStream();
}
}
/**
* @see org.apache.wicket.util.resource.IResourceStream#getLocale()
*/
public Locale getLocale()
{
return getOriginalResourceStream().getLocale();
}
/**
* @see org.apache.wicket.util.watch.IModifiable#lastModifiedTime()
*/
public Time lastModifiedTime()
{
return getOriginalResourceStream().lastModifiedTime();
}
/**
* @see org.apache.wicket.util.resource.IResourceStream#length()
*/
public long length()
{
if (supportsCompression())
{
return getCompressedContent().length;
}
else
{
return getOriginalResourceStream().length();
}
}
/**
* @see org.apache.wicket.util.resource.IResourceStream#setLocale(java.util.Locale)
*/
public void setLocale(Locale locale)
{
getOriginalResourceStream().setLocale(locale);
}
/**
* @return compressed content
*/
private byte[] getCompressedContent()
{
IResourceStream stream = getOriginalResourceStream();
try
{
byte ret[] = (byte[])cache.get();
if (ret != null && timeStamp != null)
{
if (timeStamp.equals(stream.lastModifiedTime()))
{
return ret;
}
}
ByteArrayOutputStream out = new ByteArrayOutputStream();
GZIPOutputStream zout = new GZIPOutputStream(out);
Streams.copy(stream.getInputStream(), zout);
zout.close();
stream.close();
ret = out.toByteArray();
timeStamp = stream.lastModifiedTime();
cache = new SoftReference(ret);
return ret;
}
catch (IOException e)
{
throw new RuntimeException(e);
}
catch (ResourceStreamNotFoundException e)
{
throw new RuntimeException(e);
}
}
protected abstract IResourceStream getOriginalResourceStream();
}
private static final long serialVersionUID = 1L;
/**
* 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
* @throws PackageResourceBlockedException
* when the target resource is not accepted by
* {@link IPackageResourceGuard the package resource guard}.
*/
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 CompressedPackageResource(scope, path, locale, style);
sharedResources.add(scope, path, locale, style, resource);
}
return resource;
}
private final IResourceStream resourceStream;
/**
* 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 CompressedPackageResource(Class scope, String path, Locale locale, String style)
{
super(scope, path, locale, style);
resourceStream = newResourceStream();
}
/**
* Factory method for creating resource stream instance
* @return new stream instance
*/
protected IResourceStream newResourceStream() {
return new CompressingResourceStream() {
private static final long serialVersionUID = 1L;
protected IResourceStream getOriginalResourceStream()
{
return getPackageResourceStream();
}
};
}
/**
* Returns the resource stream of package resource
* @return resource stream
*/
protected IResourceStream getPackageResourceStream() {
return CompressedPackageResource.super.getResourceStream();
}
/**
* IResourceStream implementation which compresses the data with gzip if the
* requests header Accept-Encoding contains string gzip
*
* @see org.apache.wicket.markup.html.PackageResource#getResourceStream()
*/
public IResourceStream getResourceStream()
{
return resourceStream;
}
/**
* @return Whether the client supports compression
*/
private boolean supportsCompression()
{
if (Application.get().getResourceSettings().getDisableGZipCompression())
{
return false;
}
WebRequest request = (WebRequest)WebRequestCycle.get().getRequest();
String s = request.getHttpServletRequest().getHeader("Accept-Encoding");
if (s == null)
{
return false;
}
else
{
return s.indexOf("gzip") >= 0;
}
}
/**
* @see org.apache.wicket.markup.html.WebResource#setHeaders(org.apache.wicket.protocol.http.WebResponse)
*/
protected void setHeaders(WebResponse response)
{
super.setHeaders(response);
if (supportsCompression())
{
response.setHeader("Content-Encoding", "gzip");
}
}
}