Optional 与传统 If 判断的区别

public class test18 {
    public static void main(String[] args) throws Throwable {
        System.out.println(test18.getOrderName());
    }
    public static String getOrderName() throws Throwable {
        test16 t1 = new test16("zhang", "MsdUy");
       传统if 语句
//        if (t1 != null) {
//            String orderName = t1.getOrderName();
//            if (orderName != null) {
//                return orderName.toLowerCase();
//            }
//        }
       OPtional  写法一:
          Object df = Optional.of(t1).map((Function<test16, Object>)
                test16 -> test16.getOrderName().toLowerCase())
                .orElse("df");
          return df.toString();
       OPtional  写法二:
        String elseThrow = Optional.ofNullable(t1).map(x -> x.getOrderName())
                .map(x -> x.toLowerCase())
                .orElseThrow(new Supplier<Throwable>() {
                    @Override
                    public Throwable get() {
                        return new Throwable("t1为空");
                    }
                });
        return elseThrow;
    }
}