ページングのキーアルゴリズムとDemo

     public static List getSubList(ArrayList arr,int index,int size){
        //      
        //  ，    int  ，     :10/3 = 3.xxxx = 3  ！    floor   
        int requestCount = arr.size() / size;
        
        //  null    ，       ArrayList  
        //ArrayList   List  
        if(index < 0 || index > requestCount)
            return new ArrayList();
        
        //          item    
        int from = index * size;
        
        //          
        int to = Math.min(arr.size(), (index + 1) * size);
        
        //  arr ，  offset length     
        List subList = arr.subList(from, to);
        return subList;
    }

public static ArrayList makeArrayList(int num){
    ArrayList arr = new ArrayList<>(num);
    for(int i = 0; i < num; i++){
        arr.add(i);
    }
    return arr;
}

      public static void main(String[] args) throws IOException {
        
        ArrayList list = makeArrayList(17);
        List  subList = null;
        
               //  :    10  ，   7         ,         70   
              //    ArrayList   17   ，         null  
        for(int i = 0; i < 10; i++){
              subList = getSubList(list,i,7);
              System.out.println(subList.toString());
        }
     }

[0, 1, 2, 3, 4, 5, 6]
[7, 8, 9, 10, 11, 12, 13]
[14, 15, 16]
[]
[]
[]
[]
[]
[]
[]

           ，