JAVA8之Optional总结

 User user = new User(1000L, "guodong", 99);
        User user1 = new User();
        Optional.ofNullable(user).map(data -> data.getName()).ifPresent(user1::setName);

如上图所示，使用optional可以进行对对象进行赋值。同时也可以使用optional替换三目运算符，代码如下所示：

    public static void main(String[] args) {
//        TestDemo testDemo = new TestDemo();
        TestDemo testDemo = null;
//        testDemo.setCount(null);
        //Java8-Optional：优雅，可读性较好
        int count3 = Optional.ofNullable(testDemo).map(item -> item.getCount()).orElse(1);
        System.out.println(count3);
    }

    private static class TestDemo {

        private Integer count;

        public Integer getCount() {
            return count;
        }

        public void setCount(Integer count) {
            this.count = count;
        }
    }

 

        Optional.ofNullable(item.getProductRef())
                .ifPresent(ref -> {
                    record.setRefProductId(ref.getId());
                    record.setRefProductName(ref.getDisplayText());
                    record.setSalesItemSnapshotId(ref.getSnapshotId());
                });

 

item是入参，record是出参；
Java8的实现细节，参考：https://blog.csdn.net/zjhred/article/details/84976734