/**
* 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 static org.restlet.client.engine.header.HeaderUtils.*;
import org.restlet.client.data.CharacterSet;
import org.restlet.client.data.ClientInfo;
import org.restlet.client.data.Encoding;
import org.restlet.client.data.Form;
import org.restlet.client.data.Language;
import org.restlet.client.data.MediaType;
import org.restlet.client.data.Metadata;
import org.restlet.client.data.Parameter;
import org.restlet.client.data.Preference;
import org.restlet.client.util.Series;
/**
* Preference header reader. Works for character sets, encodings, languages or
* media types.
*
* @author Jerome Louvel
*/
public class PreferenceReader<T extends Metadata> extends
HeaderReader<Preference<T>> {
public static final int TYPE_CHARACTER_SET = 1;
public static final int TYPE_ENCODING = 2;
public static final int TYPE_LANGUAGE = 3;
public static final int TYPE_MEDIA_TYPE = 4;
/**
* Parses character set preferences from a header.
*
* @param acceptCharsetHeader
* The header to parse.
* @param clientInfo
* The client info to update.
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
public static void addCharacterSets(String acceptCharsetHeader,
ClientInfo clientInfo) {
if (acceptCharsetHeader != null) {
// Implementation according to
// http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.2
if (acceptCharsetHeader.length() == 0) {
clientInfo.getAcceptedCharacterSets().add(
new Preference<CharacterSet>(CharacterSet.ISO_8859_1));
} else {
PreferenceReader pr = new PreferenceReader(
PreferenceReader.TYPE_CHARACTER_SET,
acceptCharsetHeader);
pr.addValues(clientInfo.getAcceptedCharacterSets());
}
} else {
clientInfo.getAcceptedCharacterSets().add(
new Preference(CharacterSet.ALL));
}
}
/**
* Parses encoding preferences from a header.
*
* @param acceptEncodingHeader
* The header to parse.
* @param clientInfo
* The client info to update.
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
public static void addEncodings(String acceptEncodingHeader,
ClientInfo clientInfo) {
if (acceptEncodingHeader != null) {
PreferenceReader pr = new PreferenceReader(
PreferenceReader.TYPE_ENCODING, acceptEncodingHeader);
pr.addValues(clientInfo.getAcceptedEncodings());
} else {
clientInfo.getAcceptedEncodings().add(
new Preference(Encoding.IDENTITY));
}
}
/**
* Adds language preferences from a header.
*
* @param acceptLanguageHeader
* The header to parse.
* @param clientInfo
* The client info to update.
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
public static void addLanguages(String acceptLanguageHeader,
ClientInfo clientInfo) {
if (acceptLanguageHeader != null) {
PreferenceReader pr = new PreferenceReader(
PreferenceReader.TYPE_LANGUAGE, acceptLanguageHeader);
pr.addValues(clientInfo.getAcceptedLanguages());
} else {
clientInfo.getAcceptedLanguages().add(new Preference(Language.ALL));
}
}
/**
* Parses media type preferences from a header.
*
* @param acceptMediaTypeHeader
* The header to parse.
* @param clientInfo
* The client info to update.
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
public static void addMediaTypes(String acceptMediaTypeHeader,
ClientInfo clientInfo) {
if (acceptMediaTypeHeader != null) {
PreferenceReader pr = new PreferenceReader(
PreferenceReader.TYPE_MEDIA_TYPE, acceptMediaTypeHeader);
pr.addValues(clientInfo.getAcceptedMediaTypes());
} else {
clientInfo.getAcceptedMediaTypes().add(
new Preference(MediaType.ALL));
}
}
/**
* Parses a quality value.<br>
* If the quality is invalid, an IllegalArgumentException is thrown.
*
* @param quality
* The quality value as a string.
* @return The parsed quality value as a float.
*/
public static float readQuality(String quality) {
try {
float result = Float.valueOf(quality);
if (PreferenceWriter.isValidQuality(result)) {
return result;
}
throw new IllegalArgumentException(
"Invalid quality value detected. Value must be between 0 and 1.");
} catch (NumberFormatException nfe) {
throw new IllegalArgumentException(
"Invalid quality value detected. Value must be between 0 and 1.");
}
}
/** The type of metadata read. */
private volatile int type;
/**
* Constructor.
*
* @param type
* The type of metadata read.
* @param header
* The header to read.
*/
public PreferenceReader(int type, String header) {
super(header);
this.type = type;
}
/**
* Creates a new preference.
*
* @param metadata
* The metadata name.
* @param parameters
* The parameters list.
* @return The new preference.
*/
@SuppressWarnings("unchecked")
protected Preference<T> createPreference(CharSequence metadata,
Series<Parameter> parameters) {
Preference<T> result;
if (parameters == null) {
result = new Preference<T>();
switch (this.type) {
case TYPE_CHARACTER_SET:
result.setMetadata((T) CharacterSet.valueOf(metadata.toString()));
break;
case TYPE_ENCODING:
result.setMetadata((T) Encoding.valueOf(metadata.toString()));
break;
case TYPE_LANGUAGE:
result.setMetadata((T) Language.valueOf(metadata.toString()));
break;
case TYPE_MEDIA_TYPE:
result.setMetadata((T) MediaType.valueOf(metadata.toString()));
break;
}
} else {
final Series<Parameter> mediaParams = extractMediaParams(parameters);
final float quality = extractQuality(parameters);
result = new Preference<T>(null, quality, parameters);
switch (this.type) {
case TYPE_CHARACTER_SET:
result.setMetadata((T) new CharacterSet(metadata.toString()));
break;
case TYPE_ENCODING:
result.setMetadata((T) new Encoding(metadata.toString()));
break;
case TYPE_LANGUAGE:
result.setMetadata((T) new Language(metadata.toString()));
break;
case TYPE_MEDIA_TYPE:
result.setMetadata((T) new MediaType(metadata.toString(),
mediaParams));
break;
}
}
return result;
}
/**
* Extract the media parameters. Only leave as the quality parameter if
* found. Modifies the parameters list.
*
* @param parameters
* All the preference parameters.
* @return The media parameters.
*/
protected Series<Parameter> extractMediaParams(Series<Parameter> parameters) {
Series<Parameter> result = null;
boolean qualityFound = false;
Parameter param = null;
if (parameters != null) {
result = new Form();
for (final Iterator<Parameter> iter = parameters.iterator(); !qualityFound
&& iter.hasNext();) {
param = iter.next();
if (param.getName().equals("q")) {
qualityFound = true;
} else {
iter.remove();
result.add(param);
}
}
}
return result;
}
/**
* Extract the quality value. If the value is not found, 1 is returned.
*
* @param parameters
* The preference parameters.
* @return The quality value.
*/
protected float extractQuality(Series<Parameter> parameters) {
float result = 1F;
boolean found = false;
if (parameters != null) {
Parameter param = null;
for (final Iterator<Parameter> iter = parameters.iterator(); !found
&& iter.hasNext();) {
param = iter.next();
if (param.getName().equals("q")) {
result = readQuality(param.getValue());
found = true;
// Remove the quality parameter as we will directly store it
// in the Preference object
iter.remove();
}
}
}
return result;
}
/**
* Read the next preference.
*
* @return The next preference.
*/
public Preference<T> readValue() throws IOException {
Preference<T> result = null;
boolean readingMetadata = true;
boolean readingParamName = false;
boolean readingParamValue = false;
StringBuilder metadataBuffer = new StringBuilder();
StringBuilder paramNameBuffer = null;
StringBuilder paramValueBuffer = null;
Series<Parameter> parameters = null;
int next = 0;
while (result == null) {
next = read();
if (readingMetadata) {
if ((next == -1) || isComma(next)) {
if (metadataBuffer.length() > 0) {
// End of metadata section
// No parameters detected
result = createPreference(metadataBuffer, null);
} else {
// Ignore empty metadata name
break;
}
} else if (next == ';') {
if (metadataBuffer.length() > 0) {
// End of metadata section
// Parameters detected
readingMetadata = false;
readingParamName = true;
paramNameBuffer = new StringBuilder();
parameters = new Form();
} else {
throw new IOException("Empty metadata name detected.");
}
} else if (isSpace(next)) {
// Ignore spaces
} else if (isText(next)) {
metadataBuffer.append((char) next);
} else {
throw new IOException("Unexpected character \""
+ (char) next + "\" detected.");
}
} else if (readingParamName) {
if (next == '=') {
if (paramNameBuffer.length() > 0) {
// End of parameter name section
readingParamName = false;
readingParamValue = true;
paramValueBuffer = new StringBuilder();
} else {
throw new IOException("Empty parameter name detected.");
}
} else if ((next == -1) || isComma(next)) {
if (paramNameBuffer.length() > 0) {
// End of parameters section
parameters.add(Parameter.create(paramNameBuffer, null));
result = createPreference(metadataBuffer, parameters);
} else {
throw new IOException("Empty parameter name detected.");
}
} else if (next == ';') {
// End of parameter
parameters.add(Parameter.create(paramNameBuffer, null));
paramNameBuffer = new StringBuilder();
readingParamName = true;
readingParamValue = false;
} else if (isSpace(next) && (paramNameBuffer.length() == 0)) {
// Ignore white spaces
} else if (isTokenChar(next)) {
paramNameBuffer.append((char) next);
} else {
throw new IOException("Unexpected character \""
+ (char) next + "\" detected.");
}
} else if (readingParamValue) {
if ((next == -1) || isComma(next) || isSpace(next)) {
if (paramValueBuffer.length() > 0) {
// End of parameters section
parameters.add(Parameter.create(paramNameBuffer,
paramValueBuffer));
result = createPreference(metadataBuffer, parameters);
} else {
throw new IOException("Empty parameter value detected");
}
} else if (next == ';') {
// End of parameter
parameters.add(Parameter.create(paramNameBuffer,
paramValueBuffer));
paramNameBuffer = new StringBuilder();
readingParamName = true;
readingParamValue = false;
} else if ((next == '"') && (paramValueBuffer.length() == 0)) {
// Parse the quoted string
boolean done = false;
boolean quotedPair = false;
while ((!done) && (next != -1)) {
next = read();
if (quotedPair) {
// End of quoted pair (escape sequence)
if (isText(next)) {
paramValueBuffer.append((char) next);
quotedPair = false;
} else {
throw new IOException(
"Invalid character detected in quoted string. Please check your value");
}
} else if (isDoubleQuote(next)) {
// End of quoted string
done = true;
} else if (next == '\\') {
// Begin of quoted pair (escape sequence)
quotedPair = true;
} else if (isText(next)) {
paramValueBuffer.append((char) next);
} else {
throw new IOException(
"Invalid character detected in quoted string. Please check your value");
}
}
} else if (isTokenChar(next)) {
paramValueBuffer.append((char) next);
} else {
throw new IOException("Unexpected character \""
+ (char) next + "\" detected.");
}
}
}
if (isComma(next)) {
// Unread character which isn't part of the value
unread();
}
return result;
}
}