遍歷列表數(shù)據(jù)并計(jì)算總和
public static void main(String[] args) {
List<BigDecimal> shopWithdrawDTOList = new ArrayList<>();
shopWithdrawDTOList.add(new BigDecimal("123"));
shopWithdrawDTOList.add(new BigDecimal("233"));
shopWithdrawDTOList.add(new BigDecimal("23"));
BigDecimal withdrawCount = shopWithdrawDTOList.stream()
.map(item -> item == null ? BigDecimal.ZERO : item)
.reduce(BigDecimal.ZERO, BigDecimal::add);
System.out.println(withdrawCount);
}
public static void main(String[] args) {
Stream<Integer> s = Stream.of(1, 2, 3, 4, 5, 6);
/**
* 求和
*/
Integer sum = s.reduce((integer, integer2) -> integer + integer2).get();
/**
* 求最大值
*/
Integer max = s.reduce((integer, integer2) -> integer >= integer2 ? integer : integer2).get();
}
