/*
* 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.link;
import java.io.File;
import org.apache.wicket.RequestCycle;
import org.apache.wicket.model.IModel;
import org.apache.wicket.model.Model;
import org.apache.wicket.request.target.resource.ResourceStreamRequestTarget;
import org.apache.wicket.util.resource.FileResourceStream;
import org.apache.wicket.util.resource.IResourceStream;
import org.apache.wicket.util.string.Strings;
/**
* A link that streams a file to the client. When clicked this link will prompt the save as dialog
* in the browser.
*
* NOTICE that this link will block the pagemap. That means only one link from the pagemap can be
* downloaded at a time, and also while the download happens no pages from this pagemap can be
* accessed. If you need to stream multiple files concurrently without blocking then you should use
* shared resources or a non-wicket servlet.
*
* @author Igor Vaynberg (ivaynberg)
*/
public class DownloadLink extends Link<File>
{
/**
*
*/
private static final long serialVersionUID = 1L;
/**
* File name to stream
*/
private String fileName;
private boolean deleteAfter;
/**
* Constructor. File name used will be the result of <code>file.getName()</code>
*
* @param id
* component id
* @param file
* file to stream to client
*/
public DownloadLink(String id, File file)
{
super(id);
if (file == null)
{
throw new IllegalArgumentException("file cannot be null");
}
setModel(new Model<File>(file));
}
/**
* Constructor. File name used will be the result of <code>file.getName()</code>
*
* @param id
* component id
* @param model
* model that contains the file object
*/
public DownloadLink(String id, IModel<File> model)
{
super(id, model);
}
/**
* Constructor. File name used will be the result of <code>file.getName()</code>
*
* @param id
* component id
* @param model
* model that contains the file object
* @param fileName
* name of the file
*/
public DownloadLink(String id, IModel<File> model, String fileName)
{
super(id, model);
this.fileName = fileName;
}
/**
* Constructor
*
* @param id
* component id
* @param file
* file to stream to client
* @param fileName
* name of the file
*/
public DownloadLink(String id, File file, String fileName)
{
super(id);
if (file == null)
{
throw new IllegalArgumentException("file cannot be null");
}
if (Strings.isEmpty(fileName))
{
throw new IllegalArgumentException("fileName cannot be an empty string");
}
setModel(new Model<File>(file));
this.fileName = fileName;
}
/**
*
* @see org.apache.wicket.markup.html.link.Link#onClick()
*/
@Override
public void onClick()
{
final File file = getModelObject();
if (file == null)
{
throw new IllegalStateException(getClass().getName() +
" failed to retrieve a File object from model");
}
final String fn = (fileName != null) ? fileName : file.getName();
IResourceStream resourceStream = new FileResourceStream(
new org.apache.wicket.util.file.File(file));
getRequestCycle().setRequestTarget(new ResourceStreamRequestTarget(resourceStream)
{
@Override
public String getFileName()
{
return fn;
}
@Override
public void respond(RequestCycle requestCycle)
{
super.respond(requestCycle);
if (deleteAfter)
file.delete();
}
});
}
/**
* USE THIS METHOD WITH CAUTION!
*
* If true, the file will be deleted! The recommended way to use this setting, is to set this
* DownloadLink object's model with a LoadableDetachableModel instance and the resulting file
* being generated in a temporary folder.
*
* @param deleteAfter
* true to delete file after download succeeds
* @return component
*/
public final DownloadLink setDeleteAfterDownload(boolean deleteAfter)
{
this.deleteAfter = deleteAfter;
return this;
}
}