Thread: Core Java

Help me pls. what's wrong in this code?
thanks in advance..

[code]
package Apriori;
import java.io.*;
import java.util.*;

public class Apriori extends AprioriCalculation{

public static void main(String[] args) {
AprioriCalculation ap = new AprioriCalculation();

ap.aprioriProcess();
}
}
class AprioriCalculation
{
Vector<String> candidates=new Vector<String>(); //the current candidates
String configFile="config.txt"; //configuration file
String transaFile="transa.txt"; //transaction file
String outputFile="apriori-output.txt";//output file
int numItems; //number of items per transaction
int numTransactions; //number of transactions
double minSup; //minimum support for a frequent itemset
String oneVal[]; //array of value per column that will be treated as a '1'
String itemSep = " "; //the separator value for items in the database
public void aprioriProcess()
{
Date d; //date object for timing purposes
long start, end; //start and end time
int itemsetNumber=0; //the current itemset being looked at
//get config
getConfig();

System.out.println("Apriori algorithm has started.\n");

//start timer
d = new Date();
start = d.getTime();

//while not complete
do
{
//increase the itemset that is being looked at
itemsetNumber++;

//generate the candidates
generateCandidates(itemsetNumber);

//determine and display frequent itemsets
calculateFrequentItemsets(itemsetNumber);
if(candidates.size()!=0)
{
System.out.println("Frequent " + itemsetNumber + "-itemsets");
System.out.println(candidates);
}
//if there are <=1 frequent items, then its the end. This prevents reading through the database again. When there is only one frequent itemset.
}while(candidates.size()>1);

//end timer
d = new Date();
end = d.getTime();

//display the execution time
System.out.println("Execution time is: "+((double)(end-start)/1000) + " seconds.");
}

public static String getInput()
{
String input="";
//read from System.in
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

//try to get users input, if there is an error print the message
try
{
input = reader.readLine();
}
catch (Exception e)
{
System.out.println(e);
}
return input;
}


private void getConfig()
{
FileWriter fw;
BufferedWriter file_out;

String input="";
//ask if want to change the config
System.out.println("Default Configuration: ");
System.out.println("\tRegular transaction file with '" + itemSep + "' item separator.");
System.out.println("\tConfig File: " + configFile);
System.out.println("\tTransa File: " + transaFile);
System.out.println("\tOutput File: " + outputFile);
System.out.println("\nPress 'C' to change the item separator, configuration file and transaction files");
System.out.print("or any other key to continue. ");
input=getInput();

if(input.compareToIgnoreCase("c")==0)
{
System.out.print("Enter new transaction filename (return for '"+transaFile+"'): ");
input=getInput();
if(input.compareToIgnoreCase("")!=0)
transaFile=input;

System.out.print("Enter new configuration filename (return for '"+configFile+"'): ");
input=getInput();
if(input.compareToIgnoreCase("")!=0)
configFile=input;

System.out.print("Enter new output filename (return for '"+outputFile+"'): ");
input=getInput();
if(input.compareToIgnoreCase("")!=0)
outputFile=input;

System.out.println("Filenames changed");

System.out.print("Enter the separating character(s) for items (return for '"+itemSep+"'): ");
input=getInput();
if(input.compareToIgnoreCase("")!=0)
itemSep=input;


}

try
{
FileInputStream file_in = new FileInputStream(configFile);
BufferedReader data_in = new BufferedReader(new InputStreamReader(file_in));
//number of items
numItems=Integer.valueOf(data_in.readLine()).intVa lue();

//number of transactions
numTransactions=Integer.valueOf(data_in.readLine() ).intValue();

//minsup
minSup=(Double.valueOf(data_in.readLine()).doubleV alue());

//output config info to the user
System.out.print("\nInput configuration: "+numItems+" items, "+numTransactions+" transactions, ");
System.out.println("minsup = "+minSup+"%");
System.out.println();
minSup/=100.0;

oneVal = new String[numItems];
System.out.print("Enter 'y' to change the value each row recognizes as a '1':");
if(getInput().compareToIgnoreCase("y")==0)
{
for(int i=0; i<oneVal.length; i++)
{
System.out.print("Enter value for column #" + (i+1) + ": ");
oneVal[i] = getInput();
}
}
else
for(int i=0; i<oneVal.length; i++)
oneVal[i]="1";

//create the output file
fw= new FileWriter(outputFile);
file_out = new BufferedWriter(fw);
//put the number of transactions into the output file
file_out.write(numTransactions + "\n");
file_out.write(numItems + "\n******\n");
file_out.close();
}
//if there is an error, print the message
catch(IOException e)
{
System.out.println(e);
}
}

private void generateCandidates(int n)
{
Vector<String> tempCandidates = new Vector<String>(); //temporary candidate string vector
String str1, str2; //strings that will be used for comparisons
StringTokenizer st1, st2; //string tokenizers for the two itemsets being compared

//if its the first set, candidates are just the numbers
if(n==1)
{
for(int i=1; i<=numItems; i++)
{
tempCandidates.add(Integer.toString(i));
}
}
else if(n==2) //second itemset is just all combinations of itemset 1
{
//add each itemset from the previous frequent itemsets together
for(int i=0; i<candidates.size(); i++)
{
st1 = new StringTokenizer(candidates.get(i));
str1 = st1.nextToken();
for(int j=i+1; j<candidates.size(); j++)
{
st2 = new StringTokenizer(candidates.elementAt(j));
str2 = st2.nextToken();
tempCandidates.add(str1 + " " + str2);
}
}
}
else
{
//for each itemset
for(int i=0; i<candidates.size(); i++)
{
//compare to the next itemset
for(int j=i+1; j<candidates.size(); j++)
{
//create the strigns
str1 = new String();
str2 = new String();
//create the tokenizers
st1 = new StringTokenizer(candidates.get(i));
st2 = new StringTokenizer(candidates.get(j));

//make a string of the first n-2 tokens of the strings
for(int s=0; s<n-2; s++)
{
str1 = str1 + " " + st1.nextToken();
str2 = str2 + " " + st2.nextToken();
}

//if they have the same n-2 tokens, add them together
if(str2.compareToIgnoreCase(str1)==0)
tempCandidates.add((str1 + " " + st1.nextToken() + " " + st2.nextToken()).trim());
}
}
}
//clear the old candidates
candidates.clear();
//set the new ones
candidates = new Vector<String>(tempCandidates);
tempCandidates.clear();
}

private void calculateFrequentItemsets(int n)
{
Vector<String> frequentCandidates = new Vector<String>(); //the frequent candidates for the current itemset
FileInputStream file_in; //file input stream
BufferedReader data_in; //data input stream
FileWriter fw;
BufferedWriter file_out;

StringTokenizer st, stFile; //tokenizer for candidate and transaction
boolean match; //whether the transaction has all the items in an itemset
boolean trans[] = new boolean[numItems]; //array to hold a transaction so that can be checked
int count[] = new int[candidates.size()]; //the number of successful matches

try
{
//output file
fw= new FileWriter(outputFile, true);
file_out = new BufferedWriter(fw);
//load the transaction file
file_in = new FileInputStream(transaFile);
data_in = new BufferedReader(new InputStreamReader(file_in));

//for each transaction
for(int i=0; i<numTransactions; i++)
{
//System.out.println("Got here " + i + " times"); //useful to debug files that you are unsure of the number of line
stFile = new StringTokenizer(data_in.readLine(), itemSep); //read a line from the file to the tokenizer
//put the contents of that line into the transaction array
for(int j=0; j<numItems; j++)
{
trans[j]=(stFile.nextToken().compareToIgnoreCase(oneVal[j])==0); //if it is not a 0, assign the value to true
}

//check each candidate
for(int c=0; c<candidates.size(); c++)
{
match = false; //reset match to false
//tokenize the candidate so that we know what items need to be present for a match
st = new StringTokenizer(candidates.get(c));
//check each item in the itemset to see if it is present in the transaction
while(st.hasMoreTokens())
{
match = (trans[Integer.valueOf(st.nextToken())-1]);
if(!match) //if it is not present in the transaction stop checking
break;
}
if(match) //if at this point it is a match, increase the count
count[c]++;
}

}
for(int i=0; i<candidates.size(); i++)
{
// System.out.println("Candidate: " + candidates.get(c) + " with count: " + count + " % is: " + (count/(double)numItems));
//if the count% is larger than the minSup%, add to the candidate to the frequent candidates
if((count[i]/(double)numTransactions)>=minSup)
{
frequentCandidates.add(candidates.get(i));
//put the frequent itemset into the output file
file_out.write(candidates.get(i) + "," + count[i]/(double)numTransactions + "\n");
}
}
file_out.write("-\n");
file_out.close();
}
//if error at all in this process, catch it and print the error messate
catch(IOException e)
{
System.out.println(e);
}
//clear old candidates
candidates.clear();
//new candidates are the old frequent candidates
candidates = new Vector<String>(frequentCandidates);
frequentCandidates.clear();
}
}

[Error:]
Exception in thread "main" java.lang.NoClassDefFoundError: Apriori (wrong name:
Apriori/Apriori)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java :620)
at java.security.SecureClassLoader.defineClass(Secure ClassLoader.java:12
4)
at java.net.URLClassLoader.defineClass(URLClassLoader .java:260)
at java.net.URLClassLoader.access$100(URLClassLoader. java:56)
at java.net.URLClassLoader$1.run(URLClassLoader.java: 195)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.j ava:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 06)
at sun.misc.Launcher$AppClassLoader.loadClass(Launche r.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:2 51)
at java.lang.ClassLoader.loadClassInternal(ClassLoade r.java:319)