_.mapToNonNullSum

public static <T, N extends Number> N mapToNonNullSum(List<T> dataSources, Function<T, N> mapper)

参数

• dataSources (List<T>) 待参加计算的数据信息。
• mapper 指定数据参与计算的属性

返回值

• <N extends Number> 返回一个Number数学计算结果

例子

List<Person> peoples = Arrays.asList(

new Person(12, "孙悟空"),

new Person(null, "猪八戒"),

new Person(12, "孙悟空")

);

Integer totalInteger = EnhanceStream.mapToNonNullSum(peoples, Person::getAge);

Console.log(totalInteger);

//=>24

List<Long> longs = Arrays.asList(1L, 2L, 3L);

Long totalLong = EnhanceStream.mapToNonNullSum(longs, Function.identity());

Console.log(totalLong);

//=>6

List<Double> doubles = Arrays.asList(1.1d, 2.2d, 3.3d);

Double totalDouble = EnhanceStream.mapToNonNullSum(doubles, Function.identity());

Console.log(totalDouble);

//=>6.6