org.glassfish.jersey.message.internal.LinkProvider Maven / Gradle / Ivy
/*
* Copyright (c) 2010, 2019 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package org.glassfish.jersey.message.internal;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.ws.rs.core.Link;
import javax.inject.Singleton;
import org.glassfish.jersey.internal.LocalizationMessages;
import org.glassfish.jersey.internal.util.Tokenizer;
import org.glassfish.jersey.spi.HeaderDelegateProvider;
import static org.glassfish.jersey.message.internal.Utils.throwIllegalArgumentExceptionIfNull;
/**
* Provider for Link Headers.
*
* @author Santiago Pericas-Geertsen
* @author Marek Potociar
*/
@Singleton
public class LinkProvider implements HeaderDelegateProvider {
private static final Logger LOGGER = Logger.getLogger(LinkProvider.class.getName());
@Override
public boolean supports(final Class type) {
return Link.class.isAssignableFrom(type);
}
@Override
public Link fromString(final String value) throws IllegalArgumentException {
return initBuilder(new JerseyLink.Builder(), value).build();
}
/**
* Initialize an existing Jersey link builder with the link data provided in a form of a string.
*
* @param lb link builder to be initialized.
* @param value link data as a string.
* @return initialized link builder.
*/
static JerseyLink.Builder initBuilder(JerseyLink.Builder lb, String value) {
throwIllegalArgumentExceptionIfNull(value, LocalizationMessages.LINK_IS_NULL());
try {
value = value.trim();
final String params;
if (value.startsWith("<")) {
final int gtIndex = value.indexOf('>');
if (gtIndex != -1) {
lb.uri(value.substring(1, gtIndex).trim());
params = value.substring(gtIndex + 1).trim();
} else {
throw new IllegalArgumentException("Missing token > in " + value);
}
} else {
throw new IllegalArgumentException("Missing starting token < in " + value);
}
final StringTokenizer st = new StringTokenizer(params, ";=\"", true);
while (st.hasMoreTokens()) {
checkToken(st, ";");
final String n = st.nextToken().trim();
checkToken(st, "=");
String v = nextNonEmptyToken(st);
if (v.equals("\"")) {
v = st.nextToken();
checkToken(st, "\"");
}
lb.param(n, v);
}
} catch (final Throwable e) {
if (LOGGER.isLoggable(Level.FINER)) {
LOGGER.log(Level.FINER, "Error parsing link value '" + value + "'", e);
}
lb = null;
}
if (lb == null) {
throw new IllegalArgumentException("Unable to parse link " + value);
}
return lb;
}
private static String nextNonEmptyToken(final StringTokenizer st) throws IllegalArgumentException {
String token;
do {
token = st.nextToken().trim();
} while (token.length() == 0);
return token;
}
private static void checkToken(final StringTokenizer st, final String expected) throws IllegalArgumentException {
String token;
do {
token = st.nextToken().trim();
} while (token.length() == 0);
if (!token.equals(expected)) {
throw new IllegalArgumentException("Expected token " + expected + " but found " + token);
}
}
@Override
public String toString(final Link value) {
return stringfy(value);
}
/**
* Convert {@link Link} instance to a string version.
*
* @param value link instance to be stringified.
* @return string version of a given link instance.
*/
static String stringfy(final Link value) {
throwIllegalArgumentExceptionIfNull(value, LocalizationMessages.LINK_IS_NULL());
final Map map = value.getParams();
final StringBuilder sb = new StringBuilder();
sb.append('<').append(value.getUri()).append('>');
for (final Map.Entry entry : map.entrySet()) {
sb.append("; ").append(entry.getKey()).append("=\"").append(entry.getValue()).append("\"");
}
return sb.toString();
}
/**
* Extract the list of link relations from the string value of a {@link Link#REL} attribute.
*
* @param rel string value of the link {@code "rel"} attribute.
* @return list of relations in the {@code "rel"} attribute string value.
*/
static List getLinkRelations(final String rel) {
return (rel == null) ? null : Arrays.asList(Tokenizer.tokenize(rel, "\" "));
}
}