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Greg...
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Posted: Aug 20, 2003 6:08 AM
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And to all the others who are willing to post opinion...
So here is the program again this time I don*t think that it is too messy...
import java.util.*;
/**
*This class will make the hash table.The key that the hash table uses will be
*the sourceID of the relation.And the value will be a vector which consists of
*the relations that have the same sourceID as the so given relation.
*the program gives a nullpointer exception.(...)
* @author tusheva
*/
public class AnnotationThread {
private Vector v;
private Hashtable hashtable;
/** Creates a new instance of AnnotationThread
*Just to mention that Relation is interface that is
*implemented by the class Analogy so that when I call
*the makeHashtable() methos in main I call it with an
*instance of Analogy that implements Relation so
*that is not a problem I hope..
*/
public AnnotationThread(Relation r) {
Vector v = new Vector();
Hashtable hashtable = new Hashtable();
}
public Hashtable createHashtable(Relation r){
String key1 = r.getSourceID();
if (v.isEmpty()) {
v.add(r);
hashtable.put(key1,v);
}
else {
Vector v1=(Vector) hashtable.get(key1);
v.add(v1);
hashtable.put(key1, v);
}
return hashtable;
}
public static void main (String args[]){
Analogy a = new Analogy(0.1f,0.2f,"a","b");
AnnotationThread example = new AnnotationThread(a);
System.out.println(example.createHashtable(a));
}
}
And maybe it will be useful to attach the Analogy class...
/**
*One of the structure relations named Analogy.
* @author tusheva
*/
public class Analogy implements Relation {
/**The fields of the instances of the class Analogy*/
private float sourceWeight;
private float destinationWeight;
private static final String RELATIONTYPE = "Analogy";
private String sourceID;
private String destinationID;
/** Creates a new instance of Analogy*/
public Analogy(float sourceWeight, float destinationWeight,String sourceID,String destinationID) {
this.sourceWeight = sourceWeight;
this.destinationWeight = destinationWeight;
this.sourceID=sourceID;
this.destinationID=destinationID;
all.add(this);
}
/**
* Calculates the weight for the source and destination node (according to
* its relation type)
* @return the weight
*/
public float calculateWeight(){
float weight;
weight=this.sourceWeight+this.destinationWeight-this.sourceWeight*this.destinat ionWeight;
return weight;
}
/**
* Sets the source weight.
* @param sourceWeight the source weight
*/
public void setSourceWeight(float sourceWeight) {
this.sourceWeight = sourceWeight;
}
/**
* Sets the destination weight.
* @param destinationWeight the destination weight
*/
public void setDestinationWeight(float destinationWeight) {
this.destinationWeight = destinationWeight;
}
/**
* Gets the source weight.
*/
public float getSourceWeight() {
return this.sourceWeight;
}
/**
* Gets the destination weight.
*/
public float getDestinationWeight() {
return this.destinationWeight;
}
/**
* Gets the relationstype.
*/
public String getRelationType() {
return this.RELATIONTYPE;
}
public void setSourceID(String sourceID) {
this.sourceID=sourceID;
}
public void setDestinationID(String destinationID) {
this.destinationID=destinationID;
}
public String getSourceID(){
return this.sourceID;
}
public String getDestinationID(){
return this.destinationID;
}
}
And still I do get this exception ... I mean the nullpointer exception ... After all I do initialise v and hashtable in the constructor... Does this mean that they are not visible for creteHashtable() .. I will really appreciate an answer
Cheers
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