1、实体类
2、ifPresent
Optional.ofNullable(user)
.map(User::getAddress)
.filter(entity->entity.getLocation()!=null)
.ifPresent(consumer->{
System.out.println(user);
});
Address address2= new Address();
address2.setLocation("上海");
3、orElse
Address address11 = Optional.ofNullable(user)
.map(User::getAddress)
.filter(entity -> entity.getLocation() != null)
.orElse(address2);
4、orElseThrow
Address address22 = Optional.ofNullable(user)
.map(User::getAddress)
.filter(entity -> entity.getLocation() != null)
.orElseThrow(()->new RuntimeException("错误"));
5、orElseGet
Address address33 = Optional.ofNullable(user)
.map(User::getAddress)
.filter(entity -> entity.getLocation() != null)
.orElseGet(()->new Address());