bdi4jade

diff --git a/bdi-jade/src/bdi4jade/plan/AbstractPlan.java b/bdi-jade/src/bdi4jade/plan/AbstractPlan.java
new file mode 100644
index 0000000..0ada74c
--- /dev/null
+++ b/bdi-jade/src/bdi4jade/plan/AbstractPlan.java
@@ -0,0 +1,282 @@
+//----------------------------------------------------------------------------
+// Copyright (C) 2011  Ingrid Nunes
+// 
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+// 
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+// 
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+// 
+// To contact the authors:
+// http://inf.ufrgs.br/~ingridnunes/bdi4jade/
+//
+//----------------------------------------------------------------------------
+
+package bdi4jade.plan;
+
+import jade.lang.acl.ACLMessage;
+import jade.lang.acl.MessageTemplate;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import bdi4jade.core.PlanLibrary;
+import bdi4jade.exception.PlanInstantiationException;
+import bdi4jade.goal.Goal;
+import bdi4jade.message.MessageGoal;
+import bdi4jade.softgoal.PlanContribution;
+import bdi4jade.softgoal.PlanGoalDependency;
+import bdi4jade.softgoal.Softgoal;
+import bdi4jade.util.MetadataElementImpl;
+
+/**
+ * This class represents the plan abstraction. It defines the goals that the
+ * plan can achieve, in which context, and knows which is its plan body.
+ * 
+ * @author ingrid
+ */
+public abstract class AbstractPlan extends MetadataElementImpl implements Plan {
+
+	private final Set<Class<? extends Goal>> goals;
+	protected final String id;
+	private final Set<MessageTemplate> messageTemplates;
+	private PlanLibrary planLibrary;
+
+	/**
+	 * Constructs a new Plan. It sets the plan library and plan body class of
+	 * this plan, and initializes the goals that it can achieve and message
+	 * templates of messages it can process.
+	 * 
+	 * @param id
+	 *            plan identifier
+	 */
+	public AbstractPlan(String id) {
+		this(id, null, null);
+	}
+
+	/**
+	 * Constructs a new Plan. It sets the plan library and plan body class of
+	 * this plan, and initializes the goals that it can achieve and messages it
+	 * can process. The goals are initialized with the provided goal class.
+	 * 
+	 * @param id
+	 *            plan identifier
+	 * @param goalClass
+	 *            the goal that this plan can achieve
+	 */
+	public AbstractPlan(String id, Class<? extends Goal> goalClass) {
+		this(id, goalClass, null);
+	}
+
+	/**
+	 * Constructs a new Plan. It sets the plan library and plan body class of
+	 * this plan, and initializes the goals that it can achieve and messages it
+	 * can process. The goals are initialized with the provided goal class. The
+	 * message templates is initialized with the provided template.
+	 * 
+	 * @param id
+	 *            plan identifier
+	 * @param goalClass
+	 *            the goal that this plan can achieve
+	 * @param messageTemplate
+	 *            the template of messages that this plan can process.
+	 */
+	public AbstractPlan(String id, Class<? extends Goal> goalClass,
+			MessageTemplate messageTemplate) {
+		if (id == null) {
+			throw new RuntimeException("Plan id cannot be null.");
+		}
+		this.id = id;
+		this.goals = new HashSet<Class<? extends Goal>>();
+		if (goalClass != null) {
+			this.goals.add(goalClass);
+		}
+		initGoals();
+		this.messageTemplates = new HashSet<MessageTemplate>();
+		if (messageTemplate != null) {
+			this.messageTemplates.add(messageTemplate);
+		}
+		initMessageTemplates();
+
+		// Metadata
+		putMetadata(DefaultMetadata.CONTRIBUTIONS,
+				new HashMap<Softgoal, List<PlanContribution>>());
+		putMetadata(DefaultMetadata.DEPENDENCIES,
+				new ArrayList<PlanGoalDependency>());
+	}
+
+	/**
+	 * Constructs a new Plan. It sets the plan library and plan body class of
+	 * this plan, and initializes the goals that it can achieve and message
+	 * templates of messages it can process. The message templates is
+	 * initialized with the provided template.
+	 * 
+	 * @param id
+	 *            the plan identifier
+	 * @param messageTemplate
+	 *            the template of messages that this plan can process.
+	 */
+	public AbstractPlan(String id, MessageTemplate messageTemplate) {
+		this(id, null, messageTemplate);
+
+	}
+
+	/**
+	 * Adds a goal class that this plan may achieve.
+	 * 
+	 * @param goalClass
+	 *            the goal class that can be achieved by this plan.
+	 */
+	public void addGoal(Class<? extends Goal> goalClass) {
+		this.goals.add(goalClass);
+	}
+
+	/**
+	 * Adds a message template of messages that this plan can process.
+	 * 
+	 * @param messageTemplate
+	 *            the message template of messages that can be processed.
+	 */
+	public void addMessageTemplate(MessageTemplate messageTemplate) {
+		this.messageTemplates.add(messageTemplate);
+	}
+
+	/**
+	 * Verifies if a given goal can be achieved by this plan. When the goal is a
+	 * {@link MessageGoal}, it invokes the method
+	 * {@link AbstractPlan#canProcess(ACLMessage)}. Otherwise, it checks if the
+	 * class of this goal is contained in the goal set of this plan.
+	 * 
+	 * @param goal
+	 *            the goal to be verified.
+	 * @return true if the given goal can be achieved by this plan, false
+	 *         otherwise.
+	 */
+	public boolean canAchieve(Goal goal) {
+		if (goal instanceof MessageGoal) {
+			return canProcess(((MessageGoal) goal).getMessage());
+		} else {
+			return goals.contains(goal.getClass()) ? matchesContext(goal)
+					: false;
+		}
+	}
+
+	/**
+	 * Verifies if the message received matches with any of the message
+	 * templates of this plan.
+	 * 
+	 * @param message
+	 *            the message to be checked.
+	 * @return true if this plan can process the message.
+	 */
+	public boolean canProcess(ACLMessage message) {
+		for (MessageTemplate template : messageTemplates) {
+			if (template.match(message))
+				return true;
+		}
+		return false;
+	}
+
+	/**
+	 * Instantiate the plan body of this plan. It must implement the
+	 * {@link PlanBodyInterface} interface.
+	 * 
+	 * @return the instantiated plan body.
+	 * @throws PlanInstantiationException
+	 *             if an error occurred during the instantiation process.
+	 */
+	public abstract PlanBodyInterface createPlanBody()
+			throws PlanInstantiationException;
+
+	/**
+	 * @see java.lang.Object#equals(java.lang.Object)
+	 */
+	@Override
+	public boolean equals(Object obj) {
+		if (!(obj instanceof AbstractPlan))
+			return false;
+		return this.id.equals(((AbstractPlan) obj).id);
+	}
+
+	/**
+	 * @return the id
+	 */
+	public String getId() {
+		return id;
+	}
+
+	/**
+	 * @return the planLibrary
+	 */
+	public PlanLibrary getPlanLibrary() {
+		return planLibrary;
+	}
+
+	/**
+	 * @see java.lang.Object#hashCode()
+	 */
+	@Override
+	public int hashCode() {
+		return this.id.hashCode();
+	}
+
+	/**
+	 * This method is invoked in the Plan constructor. It is responsible for
+	 * initializing the goals that this plan can achieve. The method should be
+	 * overridden by subclasses.
+	 */
+	protected void initGoals() {
+
+	}
+
+	/**
+	 * This method is invoked in the Plan constructor. It is responsible for
+	 * initializing the message templates that this plan can process. The method
+	 * should be overridden by subclasses.
+	 */
+	protected void initMessageTemplates() {
+
+	}
+
+	/**
+	 * Verifies that this plan can be executed in the current context. The
+	 * method should be overridden by subclasses.
+	 * 
+	 * @param goal
+	 *            the goal to be achieved
+	 * 
+	 * @return true if the context matches with the conditions needed for this
+	 *         plan execution.
+	 */
+	protected boolean matchesContext(Goal goal) {
+		return true;
+	}
+
+	/**
+	 * @param planLibrary
+	 *            the planLibrary to set
+	 */
+	public void setPlanLibrary(PlanLibrary planLibrary) {
+		this.planLibrary = planLibrary;
+	}
+
+	/**
+	 * @see java.lang.Object#toString()
+	 */
+	@Override
+	public String toString() {
+		return id;
+	}
+
+}

diff --git a/bdi-jade/src/bdi4jade/plan/Plan.java b/bdi-jade/src/bdi4jade/plan/Plan.java
index 811310f..3a63784 100644
--- a/bdi-jade/src/bdi4jade/plan/Plan.java
+++ b/bdi-jade/src/bdi4jade/plan/Plan.java
@@ -22,32 +22,20 @@
 
 package bdi4jade.plan;
 
-import jade.core.behaviours.Behaviour;
 import jade.lang.acl.ACLMessage;
-import jade.lang.acl.MessageTemplate;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-
 import bdi4jade.core.PlanLibrary;
 import bdi4jade.exception.PlanInstantiationException;
 import bdi4jade.goal.Goal;
 import bdi4jade.message.MessageGoal;
-import bdi4jade.softgoal.PlanContribution;
-import bdi4jade.softgoal.PlanGoalDependency;
-import bdi4jade.softgoal.Softgoal;
-import bdi4jade.util.MetadataElementImpl;
+import bdi4jade.util.MetadataElement;
 
 /**
- * This class represents the plan abstraction. It defines the goals that the
- * plan can achieve, in which context, and knows which is its plan body.
+ * This interfaces represents the plan abstraction. It defines the goals that
+ * the plan can achieve, in which context, and knows which is its plan body.
  * 
  * @author ingrid
  */
-public abstract class Plan extends MetadataElementImpl {
+public interface Plan extends MetadataElement {
 
 	public enum DefaultMetadata {
 
@@ -64,110 +52,6 @@ public abstract class Plan extends MetadataElementImpl {
 		FAILED, SUCCESSFUL;
 	}
 
-	private final Set<Class<? extends Goal>> goals;
-	protected final String id;
-	private final Set<MessageTemplate> messageTemplates;
-	private PlanLibrary planLibrary;
-
-	/**
-	 * Constructs a new Plan. It sets the plan library and plan body class of
-	 * this plan, and initializes the goals that it can achieve and message
-	 * templates of messages it can process.
-	 * 
-	 * @param id
-	 *            plan identifier
-	 */
-	public Plan(String id) {
-		this(id, null, null);
-	}
-
-	/**
-	 * Constructs a new Plan. It sets the plan library and plan body class of
-	 * this plan, and initializes the goals that it can achieve and messages it
-	 * can process. The goals are initialized with the provided goal class.
-	 * 
-	 * @param id
-	 *            plan identifier
-	 * @param goalClass
-	 *            the goal that this plan can achieve
-	 */
-	public Plan(String id, Class<? extends Goal> goalClass) {
-		this(id, goalClass, null);
-	}
-
-	/**
-	 * Constructs a new Plan. It sets the plan library and plan body class of
-	 * this plan, and initializes the goals that it can achieve and messages it
-	 * can process. The goals are initialized with the provided goal class. The
-	 * message templates is initialized with the provided template.
-	 * 
-	 * @param id
-	 *            plan identifier
-	 * @param goalClass
-	 *            the goal that this plan can achieve
-	 * @param messageTemplate
-	 *            the template of messages that this plan can process.
-	 */
-	public Plan(String id, Class<? extends Goal> goalClass,
-			MessageTemplate messageTemplate) {
-		if (id == null) {
-			throw new RuntimeException("Plan id cannot be null.");
-		}
-		this.id = id;
-		this.goals = new HashSet<Class<? extends Goal>>();
-		if (goalClass != null) {
-			this.goals.add(goalClass);
-		}
-		initGoals();
-		this.messageTemplates = new HashSet<MessageTemplate>();
-		if (messageTemplate != null) {
-			this.messageTemplates.add(messageTemplate);
-		}
-		initMessageTemplates();
-
-		// Metadata
-		putMetadata(DefaultMetadata.CONTRIBUTIONS,
-				new HashMap<Softgoal, List<PlanContribution>>());
-		putMetadata(DefaultMetadata.DEPENDENCIES,
-				new ArrayList<PlanGoalDependency>());
-	}
-
-	/**
-	 * Constructs a new Plan. It sets the plan library and plan body class of
-	 * this plan, and initializes the goals that it can achieve and message
-	 * templates of messages it can process. The message templates is
-	 * initialized with the provided template.
-	 * 
-	 * @param id
-	 *            the plan identifier
-	 * @param messageTemplate
-	 *            the template of messages that this plan can process.
-	 */
-	public Plan(String id, MessageTemplate messageTemplate) {
-		this(id, null, messageTemplate);
-
-	}
-
-	/**
-	 * Adds a goal class that this plan may achieve.
-	 * 
-	 * @param goalClass
-	 *            the goal class that can be achieved by this plan.
-	 */
-	public void addGoal(Class<? extends Goal> goalClass) {
-		this.goals.add(goalClass);
-	}
-
-	/**
-	 * Adds a message template of messages that this plan can process.
-	 * 
-	 * @param messageTemplate
-	 *            the message template of messages that can be processed.
-	 */
-	public void addMessageTemplate(MessageTemplate messageTemplate) {
-		this.messageTemplates.add(messageTemplate);
-	}
-
 	/**
 	 * Verifies if a given goal can be achieved by this plan. When the goal is a
 	 * {@link MessageGoal}, it invokes the method
@@ -179,14 +63,7 @@ public abstract class Plan extends MetadataElementImpl {
 	 * @return true if the given goal can be achieved by this plan, false
 	 *         otherwise.
 	 */
-	public boolean canAchieve(Goal goal) {
-		if (goal instanceof MessageGoal) {
-			return canProcess(((MessageGoal) goal).getMessage());
-		} else {
-			return goals.contains(goal.getClass()) ? matchesContext(goal)
-					: false;
-		}
-	}
+	public boolean canAchieve(Goal goal);
 
 	/**
 	 * Verifies if the message received matches with any of the message
@@ -196,13 +73,7 @@ public abstract class Plan extends MetadataElementImpl {
 	 *            the message to be checked.
 	 * @return true if this plan can process the message.
 	 */
-	public boolean canProcess(ACLMessage message) {
-		for (MessageTemplate template : messageTemplates) {
-			if (template.match(message))
-				return true;
-		}
-		return false;
-	}
+	public boolean canProcess(ACLMessage message);
 
 	/**
 	 * Instantiate the plan body of this plan. It must implement the
@@ -216,83 +87,19 @@ public abstract class Plan extends MetadataElementImpl {
 			throws PlanInstantiationException;
 
 	/**
-	 * @see java.lang.Object#equals(java.lang.Object)
-	 */
-	@Override
-	public boolean equals(Object obj) {
-		if (!(obj instanceof Plan))
-			return false;
-		return this.id.equals(((Plan) obj).id);
-	}
-
-	/**
 	 * @return the id
 	 */
-	public String getId() {
-		return id;
-	}
+	public String getId();
 
 	/**
 	 * @return the planLibrary
 	 */
-	public PlanLibrary getPlanLibrary() {
-		return planLibrary;
-	}
-
-	/**
-	 * @see java.lang.Object#hashCode()
-	 */
-	@Override
-	public int hashCode() {
-		return this.id.hashCode();
-	}
-
-	/**
-	 * This method is invoked in the Plan constructor. It is responsible for
-	 * initializing the goals that this plan can achieve. The method should be
-	 * overridden by subclasses.
-	 */
-	protected void initGoals() {
-
-	}
-
-	/**
-	 * This method is invoked in the Plan constructor. It is responsible for
-	 * initializing the message templates that this plan can process. The method
-	 * should be overridden by subclasses.
-	 */
-	protected void initMessageTemplates() {
-
-	}
-
-	/**
-	 * Verifies that this plan can be executed in the current context. The
-	 * method should be overridden by subclasses.
-	 * 
-	 * @param goal
-	 *            the goal to be achieved
-	 * 
-	 * @return true if the context matches with the conditions needed for this
-	 *         plan execution.
-	 */
-	protected boolean matchesContext(Goal goal) {
-		return true;
-	}
+	public PlanLibrary getPlanLibrary();
 
 	/**
 	 * @param planLibrary
 	 *            the planLibrary to set
 	 */
-	public void setPlanLibrary(PlanLibrary planLibrary) {
-		this.planLibrary = planLibrary;
-	}
-
-	/**
-	 * @see java.lang.Object#toString()
-	 */
-	@Override
-	public String toString() {
-		return id;
-	}
+	public void setPlanLibrary(PlanLibrary planLibrary);
 
 }

diff --git a/bdi-jade/src/bdi4jade/util/plan/SimplePlan.java b/bdi-jade/src/bdi4jade/util/plan/SimplePlan.java
index a55008a..3e978ef 100644
--- a/bdi-jade/src/bdi4jade/util/plan/SimplePlan.java
+++ b/bdi-jade/src/bdi4jade/util/plan/SimplePlan.java
@@ -26,7 +26,7 @@ import jade.core.behaviours.Behaviour;
 import jade.lang.acl.MessageTemplate;
 import bdi4jade.exception.PlanInstantiationException;
 import bdi4jade.goal.Goal;
-import bdi4jade.plan.Plan;
+import bdi4jade.plan.AbstractPlan;
 import bdi4jade.plan.PlanBodyInterface;
 
 /**
@@ -37,7 +37,7 @@ import bdi4jade.plan.PlanBodyInterface;
  * 
  * @author ingrid
  */
-public class SimplePlan extends Plan {
+public class SimplePlan extends AbstractPlan {
 
 	protected final Class<? extends PlanBodyInterface> planBodyClass;
 

diff --git a/bdi-jade/src/bdi4jade/util/reasoning/UtilityBasedPlanSelectionStrategy.java b/bdi-jade/src/bdi4jade/util/reasoning/UtilityBasedPlanSelectionStrategy.java
index ff4647b..b317a13 100644
--- a/bdi-jade/src/bdi4jade/util/reasoning/UtilityBasedPlanSelectionStrategy.java
+++ b/bdi-jade/src/bdi4jade/util/reasoning/UtilityBasedPlanSelectionStrategy.java
@@ -31,6 +31,7 @@ import org.apache.commons.logging.LogFactory;
 
 import bdi4jade.core.BDIAgent;
 import bdi4jade.goal.Goal;
+import bdi4jade.plan.AbstractPlan;
 import bdi4jade.plan.Plan;
 import bdi4jade.preference.SoftgoalPreferences;
 import bdi4jade.reasoning.PlanSelectionStrategy;
@@ -57,7 +58,8 @@ public class UtilityBasedPlanSelectionStrategy implements PlanSelectionStrategy 
 	@SuppressWarnings("unchecked")
 	private double calculateExpectedUtility(Plan plan, Softgoal softgoal) {
 		List<PlanContribution> contributions = ((Map<Softgoal, List<PlanContribution>>) plan
-				.getMetadata(Plan.DefaultMetadata.CONTRIBUTIONS)).get(softgoal);
+				.getMetadata(AbstractPlan.DefaultMetadata.CONTRIBUTIONS))
+				.get(softgoal);
 
 		double expectedUtility = 0;
 		if (contributions != null) {