package org.jboss.resteasy.plugins.delegates;
import org.jboss.resteasy.specimpl.MultivaluedMapImpl;
import org.jboss.resteasy.spi.Link;
import org.jboss.resteasy.spi.LinkHeader;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.RuntimeDelegate;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.StringTokenizer;
/**
* @author <a href="mailto:bill@burkecentral.com">Bill Burke</a>
* @version $Revision: 1 $
*/
public class LinkHeaderDelegate implements RuntimeDelegate.HeaderDelegate<LinkHeader>
{
private static class Parser
{
private int curr;
private String value;
private LinkHeader header = new LinkHeader();
public Parser(String value)
{
this.value = value;
}
public LinkHeader getHeader()
{
return header;
}
public void parse()
{
String href = null;
MultivaluedMap<String, String> attributes = new MultivaluedMapImpl<String, String>();
while (curr < value.length())
{
char c = value.charAt(curr);
if (c == '<')
{
if (href != null)
throw new IllegalArgumentException("Unable to parse Link header. Too many links in declaration: " + value);
href = parseLink();
}
else if (c == ';' || c == ' ')
{
curr++;
continue;
}
else if (c == ',')
{
populateLink(href, attributes);
href = null;
attributes = new MultivaluedMapImpl<String, String>();
curr++;
}
else
{
parseAttribute(attributes);
}
}
populateLink(href, attributes);
}
protected void populateLink(String href, MultivaluedMap<String, String> attributes)
{
List<String> rels = attributes.get("rel");
List<String> revs = attributes.get("rev");
String title = attributes.getFirst("title");
if (title != null) attributes.remove("title");
String type = attributes.getFirst("type");
if (type != null) attributes.remove("type");
Set<String> relationships = new HashSet<String>();
if (rels != null)
{
relationships.addAll(rels);
attributes.remove("rel");
}
if (revs != null)
{
relationships.addAll(revs);
attributes.remove("rev");
}
for (String relationship : relationships)
{
StringTokenizer tokenizer = new StringTokenizer(relationship);
while (tokenizer.hasMoreTokens())
{
String rel = tokenizer.nextToken();
Link link = new Link(title, rel, href, type, attributes);
header.getLinksByRelationship().put(rel, link);
header.getLinksByTitle().put(title, link);
header.getLinks().add(link);
}
}
}
public String parseLink()
{
int end = value.indexOf('>', curr);
if (end == -1) throw new IllegalArgumentException("Unable to parse Link header. No end to link: " + value);
String href = value.substring(curr + 1, end);
curr = end + 1;
return href;
}
public void parseAttribute(MultivaluedMap<String, String> attributes)
{
int end = value.indexOf('=', curr);
if (end == -1 || end + 1 >= value.length())
throw new IllegalArgumentException("Unable to parse Link header. No end to parameter: " + value);
String name = value.substring(curr, end);
name = name.trim();
curr = end + 1;
String val = null;
if (curr >= value.length())
{
val = "";
}
else
{
if (value.charAt(curr) == '"')
{
if (curr + 1 >= value.length())
throw new IllegalArgumentException("Unable to parse Link header. No end to parameter: " + value);
curr++;
end = value.indexOf('"', curr);
if (end == -1)
throw new IllegalArgumentException("Unable to parse Link header. No end to parameter: " + value);
val = value.substring(curr, end);
curr = end + 1;
}
else
{
StringBuffer buf = new StringBuffer();
while (curr < value.length())
{
char c = value.charAt(curr);
if (c == ',' || c == ';') break;
buf.append(value.charAt(curr));
curr++;
}
val = buf.toString();
}
}
attributes.add(name, val);
}
}
public LinkHeader fromString(String value) throws IllegalArgumentException
{
return from(value);
}
public static LinkHeader from(String value) throws IllegalArgumentException
{
Parser parser = new Parser(value);
parser.parse();
return parser.getHeader();
}
public String toString(LinkHeader value)
{
return getString(value);
}
public static String getString(LinkHeader value)
{
StringBuffer buf = new StringBuffer();
for (Link link : value.getLinks())
{
if (buf.length() > 0) buf.append(", ");
buf.append(link.toString());
}
return buf.toString();
}
}