Java – try sliding windows

I try to print images like sliding windows I can't do it right Therefore, when the sliding window size is 1, it should print each element When the sliding window is 2, it should print two consecutive elements

0
1
2

01
12

0123

Please check this Code:

for(int w = 1; w <= a.length; w++) {    
    System.out.println("Window size : " + w);
    for(int i = 0; i < a.length; i++) {
        for(int j = i; j < w; j++) {
            System.out.println(j);
        }
        System.out.println();
    }
}

Solution

for(int w = 1; w <= a.length; w++){ 

for(int w = 1; w <= a.length; w++){ 
    System.out.println("Window size : " + w);
    for(int i = 0; i < a.length - w + 1; i++){
        for(int j = i; j < i + w; j++){
                System.out.print(a[j]);
        }
        System.out.println();
    }
}