common/src/main/java/org/apache/abdera2/common/protocol/RegexTargetResolver.java - abdera - Git at Google

 /*
  * 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.abdera2.common.protocol;

 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;

 import org.apache.abdera2.common.misc.Resolver;

 /**
  * <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<R extends RequestContext>
   implements Resolver<Target,R> {

     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<R> setPattern(String pattern, TargetType type) {
         return setPattern(pattern, type, new String[0]);
     }

     public RegexTargetResolver<R> 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(R request) {
         String uri = request.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, request, 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;
     }

     @SuppressWarnings("unchecked")
     public boolean equals(Object obj) {
         if (this == obj)
             return true;
         if (obj == null)
             return false;
         if (getClass() != obj.getClass())
             return false;
         final RegexTargetResolver<R> other = (RegexTargetResolver<R>)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 Iterable<String> getParameterNames() {
             Iterable<String> names = super.getParameterNames();
             Set<String> list = new HashSet<String>();
             for (String name : names)
               list.add(name);
             if (fields != null)
                 list.addAll(Arrays.asList(fields));
             return list;
         }

         @SuppressWarnings("unchecked")
         @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");
             for (String param : getParameterNames()) {
                 buf.append("    ").append(param).append(" = ").append(getParameter(param)).append("\n");
             }
             return buf.toString();
         }

         public String getIdentity() {
             return context.getUri().toString();
         }

     }

 }
	/*
	* 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.abdera2.common.protocol;

	import java.util.Arrays;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.Map;
	import java.util.Set;
	import java.util.regex.Matcher;
	import java.util.regex.Pattern;

	import org.apache.abdera2.common.misc.Resolver;

	/**
	* <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<R extends RequestContext>
	implements Resolver<Target,R> {

	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<R> setPattern(String pattern, TargetType type) {
	return setPattern(pattern, type, new String[0]);
	}

	public RegexTargetResolver<R> 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(R request) {
	String uri = request.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, request, 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;
	}

	@SuppressWarnings("unchecked")
	public boolean equals(Object obj) {
	if (this == obj)
	return true;
	if (obj == null)
	return false;
	if (getClass() != obj.getClass())
	return false;
	final RegexTargetResolver<R> other = (RegexTargetResolver<R>)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 Iterable<String> getParameterNames() {
	Iterable<String> names = super.getParameterNames();
	Set<String> list = new HashSet<String>();
	for (String name : names)
	list.add(name);
	if (fields != null)
	list.addAll(Arrays.asList(fields));
	return list;
	}

	@SuppressWarnings("unchecked")
	@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");
	for (String param : getParameterNames()) {
	buf.append(" ").append(param).append(" = ").append(getParameter(param)).append("\n");
	}
	return buf.toString();
	}

	public String getIdentity() {
	return context.getUri().toString();
	}

	}

	}