/*
* CreativeCommons.java
*
* Version: $Revision: 4566 $
*
* Date: $Date: 2009-11-26 03:20:34 +0000 (Thu, 26 Nov 2009) $
*
* Copyright (c) 2002-2009, The DSpace Foundation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of the DSpace Foundation nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
* TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
package org.dspace.license;
import java.io.InputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.StringWriter;
import java.net.URL;
import java.net.URLConnection;
import java.sql.SQLException;
import javax.xml.transform.Templates;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import org.dspace.authorize.AuthorizeException;
import org.dspace.content.Bitstream;
import org.dspace.content.BitstreamFormat;
import org.dspace.content.Bundle;
import org.dspace.content.Item;
import org.dspace.core.ConfigurationManager;
import org.dspace.core.Context;
import org.dspace.core.Utils;
public class CreativeCommons
{
/**
* The Bundle Name
*/
public static final String CC_BUNDLE_NAME = "CC-LICENSE";
private static final String CC_BS_SOURCE = "org.dspace.license.CreativeCommons";
/**
* Some BitStream Names (BSN)
*/
private static final String BSN_LICENSE_URL = "license_url";
private static final String BSN_LICENSE_TEXT = "license_text";
private static final String BSN_LICENSE_RDF = "license_rdf";
protected static Templates templates = null;
private static boolean enabled_p;
static
{
// we only check the property once
enabled_p = ConfigurationManager
.getBooleanProperty("webui.submit.enable-cc");
if (enabled_p)
{
// if defined, set a proxy server for http requests to Creative
// Commons site
String proxyHost = ConfigurationManager
.getProperty("http.proxy.host");
String proxyPort = ConfigurationManager
.getProperty("http.proxy.port");
if ((proxyHost != null) && (proxyPort != null))
{
System.setProperty("http.proxyHost", proxyHost);
System.setProperty("http.proxyPort", proxyPort);
}
}
try
{
templates = TransformerFactory.newInstance().newTemplates(
new StreamSource(CreativeCommons.class
.getResourceAsStream("CreativeCommons.xsl")));
}
catch (TransformerConfigurationException e)
{
throw new RuntimeException(e.getMessage(),e);
}
}
/**
* Simple accessor for enabling of CC
*/
public static boolean isEnabled()
{
return enabled_p;
}
// create the CC bundle if it doesn't exist
// If it does, remove it and create a new one.
private static Bundle getCcBundle(Item item)
throws SQLException, AuthorizeException, IOException
{
Bundle[] bundles = item.getBundles(CC_BUNDLE_NAME);
if ((bundles.length > 0) && (bundles[0] != null))
{
item.removeBundle(bundles[0]);
}
return item.createBundle(CC_BUNDLE_NAME);
}
/**
* This is a bit of the "do-the-right-thing" method for CC stuff in an item
*/
public static void setLicense(Context context, Item item,
String cc_license_url) throws SQLException, IOException,
AuthorizeException
{
Bundle bundle = getCcBundle(item);
// get some more information
String license_text = fetchLicenseText(cc_license_url);
String license_rdf = fetchLicenseRDF(cc_license_url);
// set the formats
BitstreamFormat bs_url_format = BitstreamFormat.findByShortDescription(
context, "License");
BitstreamFormat bs_text_format = BitstreamFormat.findByShortDescription(
context, "CC License");
BitstreamFormat bs_rdf_format = BitstreamFormat.findByShortDescription(
context, "RDF XML");
// set the URL bitstream
setBitstreamFromBytes(item, bundle, BSN_LICENSE_URL, bs_url_format,
cc_license_url.getBytes());
// set the license text bitstream
setBitstreamFromBytes(item, bundle, BSN_LICENSE_TEXT, bs_text_format,
license_text.getBytes());
// set the RDF bitstream
setBitstreamFromBytes(item, bundle, BSN_LICENSE_RDF, bs_rdf_format,
license_rdf.getBytes());
}
public static void setLicense(Context context, Item item,
InputStream licenseStm, String mimeType)
throws SQLException, IOException, AuthorizeException
{
Bundle bundle = getCcBundle(item);
// set the format
BitstreamFormat bs_format;
if (mimeType.equalsIgnoreCase("text/xml"))
{
bs_format = BitstreamFormat.findByShortDescription(context, "CC License");
}
else if (mimeType.equalsIgnoreCase("text/rdf")) {
bs_format = BitstreamFormat.findByShortDescription(context, "RDF XML");
}
else {
bs_format = BitstreamFormat.findByShortDescription(context, "License");
}
Bitstream bs = bundle.createBitstream(licenseStm);
bs.setSource(CC_BS_SOURCE);
bs.setName((mimeType != null &&
(mimeType.equalsIgnoreCase("text/xml") ||
mimeType.equalsIgnoreCase("text/rdf"))) ?
BSN_LICENSE_RDF : BSN_LICENSE_TEXT);
bs.setFormat(bs_format);
bs.update();
}
public static void removeLicense(Context context, Item item)
throws SQLException, IOException, AuthorizeException
{
// remove CC license bundle if one exists
Bundle[] bundles = item.getBundles(CC_BUNDLE_NAME);
if ((bundles.length > 0) && (bundles[0] != null))
{
item.removeBundle(bundles[0]);
}
}
public static boolean hasLicense(Context context, Item item)
throws SQLException, IOException
{
// try to find CC license bundle
Bundle[] bundles = item.getBundles(CC_BUNDLE_NAME);
if (bundles.length == 0)
{
return false;
}
// verify it has correct contents
try
{
if ((getLicenseURL(item) == null) || (getLicenseText(item) == null)
|| (getLicenseRDF(item) == null))
{
return false;
}
}
catch (AuthorizeException ae)
{
return false;
}
return true;
}
public static String getLicenseURL(Item item) throws SQLException,
IOException, AuthorizeException
{
return getStringFromBitstream(item, BSN_LICENSE_URL);
}
public static String getLicenseText(Item item) throws SQLException,
IOException, AuthorizeException
{
return getStringFromBitstream(item, BSN_LICENSE_TEXT);
}
public static String getLicenseRDF(Item item) throws SQLException,
IOException, AuthorizeException
{
return getStringFromBitstream(item, BSN_LICENSE_RDF);
}
/**
* Get Creative Commons license RDF, returning Bitstream object.
* @return bitstream or null.
*/
public static Bitstream getLicenseRdfBitstream(Item item) throws SQLException,
IOException, AuthorizeException
{
return getBitstream(item, BSN_LICENSE_RDF);
}
/**
* Get Creative Commons license Text, returning Bitstream object.
* @return bitstream or null.
*/
public static Bitstream getLicenseTextBitstream(Item item) throws SQLException,
IOException, AuthorizeException
{
return getBitstream(item, BSN_LICENSE_TEXT);
}
/**
* Get a few license-specific properties. We expect these to be cached at
* least per server run.
*/
public static String fetchLicenseText(String license_url)
{
String text_url = license_url;
byte[] urlBytes = fetchURL(text_url);
return (urlBytes != null) ? new String(urlBytes) : "";
}
public static String fetchLicenseRDF(String license_url)
{
StringWriter result = new StringWriter();
try
{
templates.newTransformer().transform(
new StreamSource(license_url + "rdf"),
new StreamResult(result)
);
}
catch (TransformerException e)
{
throw new RuntimeException(e.getMessage(),e);
}
return result.getBuffer().toString();
}
// The following two helper methods assume that the CC
// bitstreams are short and easily expressed as byte arrays in RAM
/**
* This helper method takes some bytes and stores them as a bitstream for an
* item, under the CC bundle, with the given bitstream name
*/
private static void setBitstreamFromBytes(Item item, Bundle bundle,
String bitstream_name, BitstreamFormat format, byte[] bytes)
throws SQLException, IOException, AuthorizeException
{
ByteArrayInputStream bais = new ByteArrayInputStream(bytes);
Bitstream bs = bundle.createBitstream(bais);
bs.setName(bitstream_name);
bs.setSource(CC_BS_SOURCE);
bs.setFormat(format);
// commit everything
bs.update();
}
/**
* This helper method wraps a String around a byte array returned from the
* bitstream method further down
*/
private static String getStringFromBitstream(Item item,
String bitstream_name) throws SQLException, IOException,
AuthorizeException
{
byte[] bytes = getBytesFromBitstream(item, bitstream_name);
if (bytes == null)
{
return null;
}
return new String(bytes);
}
/**
* This helper method retrieves the bytes of a bitstream for an item under
* the CC bundle, with the given bitstream name
*/
private static Bitstream getBitstream(Item item, String bitstream_name)
throws SQLException, IOException, AuthorizeException
{
Bundle cc_bundle = null;
// look for the CC bundle
try
{
Bundle[] bundles = item.getBundles(CC_BUNDLE_NAME);
if ((bundles != null) && (bundles.length > 0))
{
cc_bundle = bundles[0];
}
else
{
return null;
}
}
catch (Exception exc)
{
// this exception catching is a bit generic,
// but basically it happens if there is no CC bundle
return null;
}
return cc_bundle.getBitstreamByName(bitstream_name);
}
private static byte[] getBytesFromBitstream(Item item, String bitstream_name)
throws SQLException, IOException, AuthorizeException
{
Bitstream bs = getBitstream(item, bitstream_name);
// no such bitstream
if (bs == null)
{
return null;
}
// create a ByteArrayOutputStream
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Utils.copy(bs.retrieve(), baos);
return baos.toByteArray();
}
/**
* Fetch the contents of a URL
*/
private static byte[] fetchURL(String url_string)
{
try
{
URL url = new URL(url_string);
URLConnection connection = url.openConnection();
byte[] bytes = new byte[connection.getContentLength()];
// loop and read the data until it's done
int offset = 0;
while (true)
{
int len = connection.getInputStream().read(bytes, offset,
bytes.length - offset);
if (len == -1)
{
break;
}
offset += len;
}
return bytes;
}
catch (Exception exc)
{
return null;
}
}
}