public class Item {
private String id;
private int count;
private String name;
public int getcount()
{
return this.count;
}
public void setcount(int x)
{
this.count=x;
}
public Item(String name)
{
this.name=name;
this.id = "";
}
public Item(String id, String name)
{
this.name=name;
this.id=id;
}
public String getItemName()
{
return this.name;
}
public String getItemId()
{
return this.id;
}
}
This is my itemSet class which will contain List of items
public class ItemSet extends ArrayList<Item> {
private List<Item> hold;
ItemSet(Item item)
{
this.hold.add(item);
}
ItemSet() {
}
public List<Item> getItemSet()
{
return this.hold;
}
}
this is my transaction class
import java.sql.ResultSet;
import java.util.ArrayList;
public class Transaction extends ArrayList<ItemSet> {
// ArrayList<String> l;
public ItemSet getUniqueItem()
{
ResultSet rs;
Database d=new Database();
ItemSet unique=new ItemSet();
unique.clear();
String query="Select id,name from item";
rs=d.sendQuery(query);
try{
while(rs.next())
{
//System.out.println(rs.getString(1)+"\t"+rs.getString(2));
Item item=new Item(rs.getString(1),rs.getString(2));
unique.add(item);
}
}catch(Exception e){System.out.print(e.getMessage());
}
for(Item item:unique)
{
// System.out.println(item.getItemId()+": "+item.getItemName());
}
return unique;
}
public int countItems(ItemSet itemset)
{
ResultSet rs;
Database d=new Database();
String query="";
int count=0;
for(Item i:itemset)
{
String id=i.getItemId();
query="SELECT count(*) FROM `item_transaction` where item_id="+i;
rs=d.sendQuery(query);
try{
while(rs.next())
{
//System.out.print(rs.getString(1));
count=Integer.parseInt(rs.getString(1));
System.out.print(count+"\t");
}
}catch(Exception e){}
}
return count;
}
/*public List countItems(List<String> item)
{
ResultSet rs;
Database d=new Database();
String query="";
List<String> item_count=new ArrayList<String>();
for(String t:item)
{
query="SELECT count(*) FROM `item_transaction` where item_id="+t;
rs=d.sendQuery(query);
try{
while(rs.next())
{
item_count.add(rs.getString(1));
}
}catch(Exception e){}
}
return item_count;
}*/
}
This is my main class
public class Ap {
public static void main(String args[])
{
Transaction t=new Transaction();
Transaction Ci=new Transaction();
Transaction Li=new Transaction();
ItemSet I=t.getUniqueItem();
for(Item i:I)
{
try{
ItemSet iS=new ItemSet(i); // am not able to create new ItemSet getting null //exception
}catch(Exception e){System.out.print(e.getMessage());
}
}
Item it=null;
for(ItemSet itemSet:Ci)
{
int x=t.countItems(itemSet);
// System.out.print(x+"\t");
it.setcount(x);
if(it.getcount()>=2)
{
//Li.add(itemset);
}
}
Iterator iter=Li.iterator();
while(iter.hasNext())
{
// System.out.print(iter.next()+"\t");
}
}
}
Am not able to create new ItemSet . getting null exception .Please help
