int[] prices = {7,1,5,3,6,4};
//求出最大值的幾種方式
int max = Arrays.stream(prices).max().getAsInt();
System.out.println(max);
int max1 = Collections.max(Arrays.asList(ArrayUtils.toObject(prices)));
System.out.println(max1);
Arrays.sort(prices);
System.out.println(prices[prices.length - 1]);