Let say we have an object Draw:
class Draw {
private int num1, num2, num3;
public Draw (int num1, int num2, int num3) {
this.num1 = num1;
this.num2 = num2;
this.num3 = num3;
}
public int getNum1() {
return num1;
}
public void setNum1(int num1) {
this.num1 = num1;
}
public int getNum2() {
return num2;
}
public void setNum2(int num2) {
this.num2 = num2;
}
public int getNum3() {
return num3;
}
public void setNum3(int num3) {
this.num3 = num3;
}
public List<Integer> getResultAsList() {
return Arrays.asList(num1, num2, num3);
}
}
Now, having List of Draws, I need to get a Map where key is a number in draw and value is a count (how many times that number was drawn)
For example, having
List<Draw> drawList = Arrays.asList(new Draw(1,2,5), new Draw(1,5,6));
I want to get a map like the following: {1=2, 2=1, 5=2, 6=1}
Can I implement this using new groupingBy operations of java 8 or another new feature?
Thanks.