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java-检查数据类型以构建对象的替代方法

(java - Alternative approach for checking data types to build an object)

发布于 2020-11-28 00:40:23

我正在尝试建立一个对象,该对象根据不同的数据类型使用不同的方法。即,它不同于和withBooleanValuewithStringValuewithDateValue取决于数据类型。我所拥有的是一个字符串,并且取决于该字符串是什么(布尔值,字符串或日期),我需要构建此对象。以下是我的处理方法。

private List<Answer> getAnswers(Set<Question> questions) {
        List<Answer> answers = new ArrayList<>();
        questions.forEach(question -> {
            Answer.Builder answer = Answer.builder()
                    .withQuestion(question.question());
            if (BooleanUtils.toBooleanObject(question.value()) != null) {
                answer.withValue(AnswerValue.builder()
                        .withBooleanValue(BooleanUtils.toBoolean(question.value()))
                        .build());
            } else {
                try {
                    Date dateValue = DateUtils.parseDate(question.value(), new String[]{"dd-MM-YYYY"});
                    answer.withValue(AnswerValue.builder()
                            .withDateValue(dateValue)
                            .build());

                } catch (ParseException e) {
                    answer.withValue(AnswerValue.builder()
                            .withStringValue(question.value())
                            .build());
                }
            }
            answers.add(answer.build());
        });
        return answers;
    }

在Java8中是否有更好的方法可以做到这一点?不知何故,ifs和try-catch语句使它看起来非常复杂,我想通过一种更好的方法来减少行数和复杂性。任何建议将不胜感激。

Questioner
AnOldSoul
Viewed
22
Vlad L 2020-11-28 09:52:09

就重构代码而言,我将从这样的事情开始(由于我没有所有的类,所以它无法编译,因此可能会有一些错误):

    private List<Answer> getAnswers(Set<Question> questions) {
        List<Answer> answers = new ArrayList<>();
        questions.forEach(question -> {
            Answer.Builder answer = Answer.builder()
                    .withQuestion(question.question())
                    .withValue(parseAnswerValue(question));

            answers.add(answer.build());
        });
        return answers;
    }

    private AnswerValue parseAnswerValue(Question question) {
        Optional<AnswerValue> answerOptional = parseBoolean(question);
        if (answerOptional.isEmpty()) {
            answerOptional = parseDate(question);
        }

        return answerOptional.isEmpty() ? parseString(question) : answerOptional.get();
    }

    private Optional<AnswerValue> parseBoolean(Question question) {
        if (BooleanUtils.toBooleanObject(question.value()) != null) {
            return Optional.of(AnswerValue.builder()
                    .withBooleanValue(BooleanUtils.toBoolean(question.value()))
                    .build());
        }
        return Optional.empty();
    }

    private Optional<AnswerValue> parseDate(Question question) {
        try {
            Date dateValue = DateUtils.parseDate(question.value(), new String[]{"dd-MM-YYYY"});
            return Optional.of(AnswerValue.builder()
                    .withDateValue(dateValue)
                    .build());

        } catch (ParseException e) {
            return Optional.empty();
        }
    }


    private AnswerValue parseString(Question question) {
        return AnswerValue.builder()
                .withStringValue(question.value())
                .build();
    }

然后是这样的。同样,这将需要有一个全球日期,这可能是有问题的。同样,除了传递问题之外,还可以传递question.value()。

    private List<Answer> getAnswers(Set<Question> questions) {
        List<Answer> answers = new ArrayList<>();
        questions.forEach(question -> {
            Answer.Builder answer = Answer.builder()
                    .withQuestion(question.question())
                    .withValue(parseAnswerValue(question));

            answers.add(answer.build());
        });
        return answers;
    }

    private AnswerValue parseAnswerValue(Question question) {
        AnswerValue.Builder answerBuilder = AnswerValue.builder();
        
        if (isBoolean(question)) {
            answerBuilder.withBooleanValue(BooleanUtils.toBoolean(question.value()));
        } else if (isDate(question)) {
            answerBuilder.withDateValue(dateValue);
        } else {
            answerBuilder.withStringValue(question.value());
        }

        return answerBuilder.build();
    }

    private boolean isBoolean(Question question) {
        return BooleanUtils.toBooleanObject(question.value()) != null;
    }

    private boolean isDate(Question question) {
        try {
            dateValue = DateUtils.parseDate(question.value(), new String[]{"dd-MM-YYYY"});
            return true;
        } catch (ParseException e) {
            return false;
        }
    }