/*
* 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.resource.bundles;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletResponse;
import org.apache.wicket.markup.head.IReferenceHeaderItem;
import org.apache.wicket.request.resource.AbstractResource;
import org.apache.wicket.request.resource.IResource;
import org.apache.wicket.request.resource.PackageResource;
import org.apache.wicket.request.resource.caching.IStaticCacheableResource;
import org.apache.wicket.util.io.ByteArrayOutputStream;
import org.apache.wicket.util.io.IOUtils;
import org.apache.wicket.util.lang.Args;
import org.apache.wicket.util.lang.Bytes;
import org.apache.wicket.util.resource.AbstractResourceStream;
import org.apache.wicket.util.resource.IResourceStream;
import org.apache.wicket.util.resource.ResourceStreamNotFoundException;
import org.apache.wicket.util.time.Time;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A {@linkplain IResource resource} that concatenates several resources into one download. This
* resource can only bundle {@link PackageResource}s. The content type of the resource will be that
* of the first resource that specifies its content type.
*
* @author papegaaij
*/
public class ConcatBundleResource extends AbstractResource implements IStaticCacheableResource
{
private static final Logger log = LoggerFactory.getLogger(ConcatBundleResource.class);
private static final long serialVersionUID = 1L;
private List<? extends IReferenceHeaderItem> providedResources;
/**
* Construct.
*
* @param providedResources
*/
public ConcatBundleResource(List<? extends IReferenceHeaderItem> providedResources)
{
this.providedResources = Args.notNull(providedResources, "providedResources");
}
@Override
protected ResourceResponse newResourceResponse(Attributes attributes)
{
final ResourceResponse resourceResponse = new ResourceResponse();
if (resourceResponse.dataNeedsToBeWritten(attributes))
{
try
{
List<IResourceStream> resources = collectResourceStreams();
if (resources == null)
return sendResourceError(resourceResponse, HttpServletResponse.SC_NOT_FOUND,
"Unable to find resource");
resourceResponse.setContentType(findContentType(resources));
// add Last-Modified header (to support HEAD requests and If-Modified-Since)
final Time lastModified = findLastModified(resources);
if (lastModified != null)
resourceResponse.setLastModified(lastModified);
// read resource data
final byte[] bytes = readAllResources(resources);
// send Content-Length header
resourceResponse.setContentLength(bytes.length);
// send response body with resource data
resourceResponse.setWriteCallback(new WriteCallback()
{
@Override
public void writeData(Attributes attributes)
{
attributes.getResponse().write(bytes);
}
});
}
catch (IOException e)
{
log.debug(e.getMessage(), e);
return sendResourceError(resourceResponse, 500, "Unable to read resource stream");
}
catch (ResourceStreamNotFoundException e)
{
log.debug(e.getMessage(), e);
return sendResourceError(resourceResponse, 500, "Unable to open resource stream");
}
}
return resourceResponse;
}
private List<IResourceStream> collectResourceStreams()
{
List<IResourceStream> ret = new ArrayList<IResourceStream>(providedResources.size());
for (IReferenceHeaderItem curItem : providedResources)
{
IResourceStream stream = ((PackageResource)curItem.getReference().getResource()).getResourceStream();
if (stream == null)
return null;
ret.add(stream);
}
return ret;
}
private String findContentType(List<IResourceStream> resources)
{
for (IResourceStream curStream : resources)
if (curStream.getContentType() != null)
return curStream.getContentType();
return null;
}
private Time findLastModified(List<IResourceStream> resources)
{
Time ret = null;
for (IResourceStream curStream : resources)
{
Time curLastModified = curStream.lastModifiedTime();
if (ret == null || curLastModified.after(ret))
ret = curLastModified;
}
return ret;
}
private byte[] readAllResources(List<IResourceStream> resources) throws IOException,
ResourceStreamNotFoundException
{
ByteArrayOutputStream output = new ByteArrayOutputStream();
for (IResourceStream curStream : resources)
IOUtils.copy(curStream.getInputStream(), output);
return output.toByteArray();
}
private ResourceResponse sendResourceError(ResourceResponse resourceResponse, int errorCode,
String errorMessage)
{
String msg = String.format("bundled resource: %s (status=%d)", errorMessage, errorCode);
log.warn(msg);
resourceResponse.setError(errorCode, errorMessage);
return resourceResponse;
}
@Override
public Serializable getCacheKey()
{
ArrayList<Serializable> key = new ArrayList<Serializable>(providedResources.size());
for (IReferenceHeaderItem curItem : providedResources)
{
Serializable curKey = ((PackageResource)curItem.getReference().getResource()).getCacheKey();
if (curKey == null)
return null;
key.add(curKey);
}
return key;
}
@Override
public IResourceStream getCacheableResourceStream()
{
List<IResourceStream> resources = collectResourceStreams();
byte[] bytes = null;
try
{
bytes = readAllResources(resources);
}
catch (IOException e)
{
return null;
}
catch (ResourceStreamNotFoundException e)
{
return null;
}
final String contentType = findContentType(resources);
final Time lastModified = findLastModified(resources);
final ByteArrayInputStream inputStream = new ByteArrayInputStream(bytes);
final long length = bytes.length;
AbstractResourceStream ret = new AbstractResourceStream()
{
private static final long serialVersionUID = 1L;
@Override
public InputStream getInputStream() throws ResourceStreamNotFoundException
{
return inputStream;
}
@Override
public Bytes length()
{
return Bytes.bytes(length);
}
@Override
public String getContentType()
{
return contentType;
}
@Override
public Time lastModifiedTime()
{
return lastModified;
}
@Override
public void close() throws IOException
{
inputStream.close();
}
};
return ret;
}
}