JAVA Set 调用add(1)的时候居然出现空指针？？

[szu1411]

	
public class homework {
		public static void main(String[] args) {
			int i=0,j=0,k=0,temp1=0,temp2=0,sum=0;
	        File input = new File("u1.base.OCCF");
	        Scanner scanner=null;
	        scanner =new Scanner(input);
	        scanner.useDelimiter("[^0123456789]+");
	        
	        while(scanner.hasNextInt())
	        {
	        temp1=scanner.nextInt();
	        temp2=scanner.nextInt();
	        	i=temp1;
	        	if(sum!=i)
	        		sum++;
	        }
	        scanner.close();
	        IdRecord record[]=new IdRecord[sum];
	        Scanner scanner2=null;
	        scanner2 =new Scanner(input);
	        scanner2.useDelimiter("[^0123456789]+");
	        while(scanner2.hasNextInt())
	        {
		        temp1=scanner2.nextInt();
		        temp2=scanner2.nextInt();//这里前面没出错,数据的数量是偶数

		       //record[temp1].set.add(temp2);//这里去掉注释会报错Exception in thread "main" java.lang.NullPointerException
		       record[0].set.add(1);//这样也报错？？？
	        }
	}
}
class IdRecord{
	public HashSet<Integer> set=new HashSet<Integer>();//
	public double similarity[]=new double[20];//
	public int similarityid[] =new int [20];//
	
	public IdRecord(){
		set.clear();
		for(int i=0;i<20;i++)
		{
			similarity[i]=0;
			similarityid[i]=0;
		}
	}
}

[szu1411]

已自行解决，要循环初始化