/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. The ASF licenses this file to You
* under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License. For additional information regarding
* copyright in this work, please see the NOTICE file in the top level
* directory of this distribution.
*/
package org.apache.abdera.protocol.server.impl;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.abdera.protocol.Request;
import org.apache.abdera.protocol.Resolver;
import org.apache.abdera.protocol.server.RequestContext;
import org.apache.abdera.protocol.server.Target;
import org.apache.abdera.protocol.server.TargetType;
/**
* <p>Provides a utility class helpful for determining which type of resource
* the client is requesting. Each resource type (e.g. service doc, collection,
* entry, edit uri, media resource, etc) is assigned a regex pattern. Given
* the request URI (path and querystring), this will determine which resource
* was selected and return an appropriate TargetMatcher. TargetMatcher is
* essentially just a simplified version of the java.util.regex.Matcher that
* also specifies the Resource Type.</p>
*
* <pre>
* RequestContext request = ...
* RegexTargetResolver tr = new RegexTargetResolver();
* tr.setPattern("/atom",ResourceType.INTROSPECTION)
* .setPattern("/atom/([^/#?]+)",ResourceType.COLLECTION)
* .setPattern("/atom/([^/#?]+)/([^/#?]+)",ResourceType.ENTRY)
* .setPattern("/atom/([^/#?]+)/([^/#?]+)\\?edit",ResourceType.ENTRY_EDIT)
* .setPattern("/atom/([^/#?]+)/([^/#?]+)\\?media",ResourceType.MEDIA)
* .setPattern("/atom/([^/#?]+)/([^/#?]+)\\?edit-media",ResourceType.MEDIA_EDIT);
*
* Target target = tr.resolve(request);
* System.out.println(target.getType());
* System.out.println(targer.getParameter("foo"));
* </pre>
*
*/
public class RegexTargetResolver
implements Resolver<Target> {
protected final Map<Pattern, TargetType> patterns;
protected final Map<Pattern, String[]> fields;
public RegexTargetResolver() {
this.patterns = new HashMap<Pattern, TargetType>();
this.fields = new HashMap<Pattern, String[]>();
}
public RegexTargetResolver(Map<String, TargetType> patterns) {
this.patterns = new HashMap<Pattern, TargetType>();
this.fields = new HashMap<Pattern, String[]>();
for (String p : patterns.keySet()) {
TargetType type = patterns.get(p);
setPattern(p,type);
}
}
public RegexTargetResolver setPattern(
String pattern,
TargetType type) {
return setPattern(pattern,type, new String[0]);
}
public RegexTargetResolver setPattern(
String pattern,
TargetType type,
String... fields) {
Pattern p = Pattern.compile(pattern);
this.patterns.put(p,type);
this.fields.put(p,fields);
return this;
}
public Target resolve(Request request) {
RequestContext context = (RequestContext) request;
String uri = context.getTargetPath();
for (Pattern pattern : patterns.keySet()) {
Matcher matcher = pattern.matcher(uri);
if (matcher.matches()) {
TargetType type = this.patterns.get(pattern);
String[] fields = this.fields.get(pattern);
return getTarget(type, context, matcher, fields);
}
}
return null;
}
protected Target getTarget(
TargetType type,
RequestContext request,
Matcher matcher,
String[] fields) {
return new RegexTarget(type, request, matcher, fields);
}
public String toString() {
StringBuilder buf = new StringBuilder();
buf.append("Regex Target Resolver:\n");
for (Pattern pattern : patterns.keySet()) {
TargetType type = this.patterns.get(pattern);
String[] fields = this.fields.get(pattern);
buf.append(pattern.toString() + ", Type: " + type + ", Fields: " + Arrays.toString(fields));
}
return buf.toString();
}
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((fields == null) ? 0 : fields.hashCode());
result = prime * result + ((patterns == null) ? 0 : patterns.hashCode());
return result;
}
public boolean equals(Object obj) {
if (this == obj) return true;
if (obj == null) return false;
if (getClass() != obj.getClass()) return false;
final RegexTargetResolver other = (RegexTargetResolver) obj;
if (fields == null) {
if (other.fields != null) return false;
} else if (!fields.equals(other.fields)) return false;
if (patterns == null) {
if (other.patterns != null) return false;
} else if (!patterns.equals(other.patterns)) return false;
return true;
}
public static class RegexTarget
extends SimpleTarget
implements Target {
private static final long serialVersionUID = 165211244926064449L;
protected Matcher matcher;
protected String[] fields;
public RegexTarget(
TargetType type,
RequestContext context,
Matcher matcher,
String[] fields) {
super(type, context);
this.matcher = matcher;
this.fields = fields;
}
public String getParameter(String name) {
if (fields == null) return super.getParameter(name);
int idx = 0;
for (int n = 0; n < fields.length; n++)
if (fields[n].equalsIgnoreCase(name)) idx = n + 1;
return idx > 0 && idx <= matcher.groupCount() ?
matcher.group(idx) : super.getParameter(name);
}
public String[] getParameterNames() {
String[] names = super.getParameterNames();
List<String> list = new ArrayList<String>();
if (names != null) list.addAll(Arrays.asList(names));
if (fields != null) list.addAll(Arrays.asList(fields));
return list.toArray(new String[list.size()]);
}
@Override
public <T>T getMatcher() {
return (T)matcher.pattern();
}
@Override
public int hashCode() {
final int PRIME = 31;
int result = 1;
String m = matcher.group(0);
String p = matcher.pattern().pattern();
result = PRIME * result + super.hashCode();
result = PRIME * result + ((m == null) ? 0 : m.hashCode());
result = PRIME * result + ((p == null) ? 0 : p.hashCode());
result = PRIME * result + ((type == null) ? 0 : type.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) return true;
if (obj == null) return false;
if (getClass() != obj.getClass()) return false;
final RegexTarget other = (RegexTarget) obj;
String m = matcher.group(0);
String p = matcher.pattern().pattern();
String m2 = other.matcher.group(0);
String p2 = other.matcher.pattern().pattern();
if (!super.equals(obj)) return false;
if (m == null) {
if (m2 != null)
return false;
} else if (!m.equals(m2))
return false;
if (p == null) {
if (p2 != null)
return false;
} else if (!p.equals(p2))
return false;
if (type == null) {
if (other.type != null)
return false;
} else if (!type.equals(other.type))
return false;
return true;
}
public String toString() {
String m = matcher.group(0);
String p = matcher.pattern().pattern();
StringBuilder buf = new StringBuilder();
buf.append("RegexTarget[")
.append(p)
.append(" ==> ")
.append(m)
.append("] = ")
.append(type.toString())
.append("\n");
String[] params = getParameterNames();
for (String param : params) {
buf.append(" ")
.append(param)
.append(" = ")
.append(getParameter(param))
.append("\n");
}
return buf.toString();
}
public String getIdentity() {
return context.getUri().toString();
}
}
}