记录一次Java 8 list NPE 处理Optional.ofNullable

rookiesx

于 2025-04-03 15:31:10 发布

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文章标签： java list 开发语言

本文链接：https://blog.youkuaiyun.com/rookiesx/article/details/146982116

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源代码在没有Optional.ofNullable(list).orElse(Collections.emptyList())保护下，在多层嵌套list forEach 时出现了NullPoint Exception

            Optional.ofNullable(routesList).orElse(Collections.emptyList()).forEach(route -> {
                Optional.ofNullable(route.getLegs()).orElse(Collections.emptyList()).forEach(leg -> {
                    Optional.ofNullable(leg.getSteps()).orElse(Collections.emptyList()).forEach(step -> {
                        Optional.ofNullable(step.getRoad_names()).orElse(Collections.emptyList()).forEach(roadNameList -> {
                            actualList.add(roadNameList.getOrthography().getContent());
                        });
                    });
                });
            });