/**
* Copyright 2005-2011 Noelios Technologies.
*
* The contents of this file are subject to the terms of one of the following
* open source licenses: LGPL 3.0 or LGPL 2.1 or CDDL 1.0 or EPL 1.0 (the
* "Licenses"). You can select the license that you prefer but you may not use
* this file except in compliance with one of these Licenses.
*
* You can obtain a copy of the LGPL 3.0 license at
* http://www.opensource.org/licenses/lgpl-3.0.html
*
* You can obtain a copy of the LGPL 2.1 license at
* http://www.opensource.org/licenses/lgpl-2.1.php
*
* You can obtain a copy of the CDDL 1.0 license at
* http://www.opensource.org/licenses/cddl1.php
*
* You can obtain a copy of the EPL 1.0 license at
* http://www.opensource.org/licenses/eclipse-1.0.php
*
* See the Licenses for the specific language governing permissions and
* limitations under the Licenses.
*
* Alternatively, you can obtain a royalty free commercial license with less
* limitations, transferable or non-transferable, directly at
* http://www.noelios.com/products/restlet-engine
*
* Restlet is a registered trademark of Noelios Technologies.
*/
package org.restlet.client.engine.header;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import org.restlet.client.data.Parameter;
import org.restlet.client.data.Preference;
/**
* Preference header writer.
*
* @author Jerome Louvel
*/
public class PreferenceWriter extends HeaderWriter<Preference<?>> {
/**
* Indicates if the quality value is valid.
*
* @param quality
* The quality value.
* @return True if the quality value is valid.
*/
public static boolean isValidQuality(float quality) {
return (quality >= 0F) && (quality <= 1F);
}
/**
* Writes a list of preferences with a comma separator.
*
* @param prefs
* The list of preferences.
* @return The formatted list of preferences.
* @throws IOException
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
public static String write(List prefs) {
return new PreferenceWriter().append(prefs).toString();
}
@Override
public PreferenceWriter append(Preference<?> pref) {
append(pref.getMetadata().getName());
if (pref.getQuality() < 1F) {
append(";q=");
appendQuality(pref.getQuality());
}
if (pref.getParameters() != null) {
Parameter param;
for (Iterator<Parameter> iter = pref.getParameters().iterator(); iter
.hasNext();) {
param = iter.next();
if (param.getName() != null) {
append(';').append(param.getName());
if ((param.getValue() != null)
&& (param.getValue().length() > 0)) {
append('=').append(param.getValue());
}
}
}
}
return this;
}
/**
* Formats a quality value.<br>
* If the quality is invalid, an IllegalArgumentException is thrown.
*
* @param quality
* The quality value as a float.
* @return This writer.
*/
public PreferenceWriter appendQuality(float quality) {
if (!isValidQuality(quality)) {
throw new IllegalArgumentException(
"Invalid quality value detected. Value must be between 0 and 1.");
}
return this;
}
}