1Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
	at Lottal.getRandom(Lottal.java:21)
	at Lottal.main(Lottal.java:34)
------------------------------------------------
import java.lang.reflect.Array;
import java.util.Random;
public class Lottal {
	private int num;
	private int length;
	private int[] array=new int[length];//length是在构造方法之后才能赋值
	public Lottal(int num, int length) {
		this.num = num;
		this.length = length;
	}

	public void getRandom(){
		 Random rnd = new Random();
		 for(int i=0;i<length;i++){

			System.out.print(" "+rnd.nextInt(num+1));
			array[i]=rnd.nextInt(num+1);
		 }
	}

	public static void main(String[] args) {
		Lottal lottal = new Lottal(3,3);
		lottal.getRandom();

	}
}

----------------------------------------------------------
改完之后
import java.lang.reflect.Array;
import java.util.Random;


public class Lottal {
	private int num;
	private int length;
	private int[] array;
	public Lottal(int num, int length) {
		this.num = num;
		this.length = length;
	}

	public void getRandom(){
		 Random rnd = new Random();
		 array=new int[length];
		 for(int i=0;i<length;i++){

			System.out.print(" "+rnd.nextInt(num+1));
			array[i]=rnd.nextInt(num+1);
		 }
	}
	public static void main(String[] args) {
		Lottal lottal = new Lottal(93,3);
		lottal.getRandom();

	}
}