优化Java代码降低SonarQube认知复杂度（33→15）

现有Java代码因大量嵌套if条件，导致SonarQube检测出认知复杂度达33，远超允许的阈值15。尝试仅调整try-catch块结构后优化效果未达预期，请求重构以下代码：

原代码 #

public void retryDrools() throws InterruptedException {

    String methodName = Thread.currentThread().getStackTrace()[1].getMethodName();

    List<JeopardyRepositoryRequest> fetchedJeopardies = null;

    JepMessage jepMessage = null;

    JeopardyRepositoryRequest newjepRequest = null;

    String successStatus = null;

    String failureMessage = null;

    Date now = new Date();

    String time = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS", Locale.ENGLISH).format(now);

    LoggingUtil.LogInfo(className + "." + methodName, "Cron Job retryDrools started at " + time);

    try {

        fetchedJeopardies = jeopardyService.getJeopardyByIsDroolsCallSuccessAndJeopardyStatus(STATUS_OPEN, NO);

    } catch (JeopardyException e) {

        LoggingUtil.LogError(className + "." + methodName, "Error Occured while fetching jep by isDroolsCallSuccessAndJeopardyStatus");

    }

    for (JeopardyRepositoryRequest retryJepforDroolsCall : fetchedJeopardies) {

        try {

            List<CustomerOrder> customerOrderList = jeopardyService.getCustomerOrdersByBanOrCustomerOrderNumber(retryJepforDroolsCall.getBan(), retryJepforDroolsCall.getCustomerOrderNumber());

            if (!isEmptyOrNull(retryJepforDroolsCall.getSfdcAccountId()) && !retryJepforDroolsCall.getSfdcAccountId().equalsIgnoreCase("dummy")) {

                String customerType = jeopardyService.checkIfConsumerTypeIsSMBPots(customerOrderList) ? BUSINESS : INDIVIDUAL;

                jepMessage = jeopardyService.checkForSFCCase(retryJepforDroolsCall, customerOrderList, customerType);

                LoggingUtil.LogInfo(className + "." + methodName, "Response from checkForSFCCase " + jepMessage);

            }

            if (jepMessage != null && jepMessage.getAdditionalAttributeList() != null && !jepMessage.getAdditionalAttributeList().isEmpty()) {

                AdditionalAttributeList droolsCallSuccessAttribute = jepMessage.getAdditionalAttributeList().stream()
                        .filter(attr -> "droolscallSuccess".equalsIgnoreCase(attr.getAttributeName()))
                        .findFirst().orElse(null);

                AdditionalAttributeList droolsCallFailureMessageAttribute = jepMessage.getAdditionalAttributeList().stream()
                        .filter(attr -> "droolsFailure".equalsIgnoreCase(attr.getAttributeName()))
                        .findFirst().orElse(null);

                if (droolsCallFailureMessageAttribute != null) {

                    failureMessage = droolsCallFailureMessageAttribute.getAttributeValue();

                }

                if (droolsCallSuccessAttribute != null) {

                    successStatus = droolsCallSuccessAttribute.getAttributeValue();

                }

                retryJepforDroolsCall.setAdditionalAttributeList(jepMessage.getAdditionalAttributeList());

                LoggingUtil.LogInfo(className + "." + methodName, "Setting droolsCallSuccessAttribute in JeopardyRepositoryReqr" + droolsCallSuccessAttribute + droolsCallFailureMessageAttribute);

                String sfdcCaseApplicable = (jepMessage.getIsSfdcCaseApplicable() == true) ? YES : NO;

                retryJepforDroolsCall.setSfdcCaseApplicable(sfdcCaseApplicable);

                if (isSuccessStatusValid(successStatus) && jepMessage.getIsSfdcCaseApplicable()) {

                    newjepRequest = sfdcCaseCreationAdapter.createOrUpdateCaseinSFDC(retryJepforDroolsCall, jepMessage, "create");

                    updateSfdcCaseFields(retryJepforDroolsCall, newjepRequest);

                }

                genericWrapper.updateJeopardyById(retryJepforDroolsCall);

                LoggingUtil.LogInfo(className + "." + methodName, "saving jeopardy");

            }
        } catch (Exception e) {

            LoggingUtil.LogInfo(className + "." + methodName, " Error occurred " + failureMessage + e.getMessage());
        }
    }
}

（注：原代码存在拼写错误，如succesgStatus、LiSt等，重构时已修正）

重构后的代码 #

public void retryDrools() throws InterruptedException {
    String methodName = Thread.currentThread().getStackTrace()[1].getMethodName();
    logJobStart(methodName);

    List<JeopardyRepositoryRequest> fetchedJeopardies = fetchJeopardies(methodName);
    if (isEmptyOrNull(fetchedJeopardies)) {
        return;
    }

    for (JeopardyRepositoryRequest jeopardyRequest : fetchedJeopardies) {
        processSingleJeopardy(jeopardyRequest, methodName);
    }
}

private void logJobStart(String methodName) {
    String time = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS", Locale.ENGLISH).format(new Date());
    LoggingUtil.LogInfo(className + "." + methodName, "Cron Job retryDrools started at " + time);
}

private List<JeopardyRepositoryRequest> fetchJeopardies(String methodName) {
    try {
        return jeopardyService.getJeopardyByIsDroolsCallSuccessAndJeopardyStatus(STATUS_OPEN, NO);
    } catch (JeopardyException e) {
        LoggingUtil.LogError(className + "." + methodName, "Error Occured while fetching jep by isDroolsCallSuccessAndJeopardyStatus");
        return Collections.emptyList();
    }
}

private void processSingleJeopardy(JeopardyRepositoryRequest jeopardyRequest, String methodName) {
    try {
        List<CustomerOrder> customerOrderList = jeopardyService.getCustomerOrdersByBanOrCustomerOrderNumber(
                jeopardyRequest.getBan(), jeopardyRequest.getCustomerOrderNumber());

        JepMessage jepMessage = fetchJepMessageIfValid(jeopardyRequest, customerOrderList, methodName);
        if (jepMessage == null || isAdditionalAttributesEmpty(jepMessage)) {
            return;
        }

        updateJeopardyAttributes(jeopardyRequest, jepMessage, methodName);
        handleSfdcCaseCreation(jeopardyRequest, jepMessage, methodName);

        genericWrapper.updateJeopardyById(jeopardyRequest);
        LoggingUtil.LogInfo(className + "." + methodName, "saving jeopardy");
    } catch (Exception e) {
        LoggingUtil.LogInfo(className + "." + methodName, " Error occurred " + e.getMessage());
    }
}

private JepMessage fetchJepMessageIfValid(JeopardyRepositoryRequest jeopardyRequest, List<CustomerOrder> customerOrderList, String methodName) {
    String sfdcAccountId = jeopardyRequest.getSfdcAccountId();
    if (isEmptyOrNull(sfdcAccountId) || "dummy".equalsIgnoreCase(sfdcAccountId)) {
        return null;
    }

    String customerType = jeopardyService.checkIfConsumerTypeIsSMBPots(customerOrderList) ? BUSINESS : INDIVIDUAL;
    JepMessage jepMessage = jeopardyService.checkForSFCCase(jeopardyRequest, customerOrderList, customerType);
    LoggingUtil.LogInfo(className + "." + methodName, "Response from checkForSFCCase " + jepMessage);
    return jepMessage;
}

private boolean isAdditionalAttributesEmpty(JepMessage jepMessage) {
    return jepMessage.getAdditionalAttributeList() == null || jepMessage.getAdditionalAttributeList().isEmpty();
}

private void updateJeopardyAttributes(JeopardyRepositoryRequest jeopardyRequest, JepMessage jepMessage, String methodName) {
    AdditionalAttributeList successAttr = findAttribute(jepMessage, "droolscallSuccess");
    AdditionalAttributeList failureAttr = findAttribute(jepMessage, "droolsFailure");

    jeopardyRequest.setAdditionalAttributeList(jepMessage.getAdditionalAttributeList());
    LoggingUtil.LogInfo(className + "." + methodName, "Setting droolsCallSuccessAttribute in JeopardyRepositoryReqr" + successAttr + failureAttr);

    String sfdcCaseApplicable = jepMessage.getIsSfdcCaseApplicable() ? YES : NO;
    jeopardyRequest.setSfdcCaseApplicable(sfdcCaseApplicable);
}

private AdditionalAttributeList findAttribute(JepMessage jepMessage, String attributeName) {
    return jepMessage.getAdditionalAttributeList().stream()
            .filter(attr -> attributeName.equalsIgnoreCase(attr.getAttributeName()))
            .findFirst()
            .orElse(null);
}

private void handleSfdcCaseCreation(JeopardyRepositoryRequest jeopardyRequest, JepMessage jepMessage, String methodName) {
    AdditionalAttributeList successAttr = findAttribute(jepMessage, "droolscallSuccess");
    if (successAttr == null || !YES.equalsIgnoreCase(successAttr.getAttributeValue()) || !jepMessage.getIsSfdcCaseApplicable()) {
        return;
    }

    JeopardyRepositoryRequest newJepRequest = sfdcCaseCreationAdapter.createOrUpdateCaseinSFDC(jeopardyRequest, jepMessage, "create");
    updateSfdcCaseFields(jeopardyRequest, newJepRequest);
}

private void updateSfdcCaseFields(JeopardyRepositoryRequest jeopardyRequest, JeopardyRepositoryRequest newJepRequest) {
    if (newJepRequest == null) {
        return;
    }

    if (newJepRequest.getSfdCaseId() != null && newJepRequest.getSfdcCaseNumber() != null) {
        jeopardyRequest.setSfdcCaseId(newJepRequest.getSfdCaseId());
        jeopardyRequest.setSfdcCaseNumber(newJepRequest.getSfdcCaseNumber());
        jeopardyRequest.setSfdcCaseCreationStatus(SUCCESS);
    } else if (newJepRequest.getSfdCaseError() != null) {
        jeopardyRequest.setSfdcCaseError(newJepRequest.getSfdCaseError());
        jeopardyRequest.setSfdcCaseCreationStatus(FAILURE);
    }
}

// 空值判断工具方法
private boolean isEmptyOrNull(Object obj) {
    if (obj == null) {
        return true;
    }
    if (obj instanceof String) {
        return ((String) obj).trim().isEmpty();
    }
    if (obj instanceof Collection) {
        return ((Collection<?>) obj).isEmpty();
    }
    return false;
}

重构核心措施 #

• 拆分大方法：将原方法拆分为多个单一职责的小方法（日志记录、数据获取、单条数据处理等），降低单个方法的复杂度
• 提前返回：条件不满足时直接返回，避免嵌套if层级堆积
• 提取重复逻辑：将属性查找、空值判断等重复逻辑封装为独立方法，减少代码冗余
• 简化条件判断：把复杂复合条件拆分为可读性更强的方法调用，减少嵌套深度
• 优化变量处理：避免null初始化，返回空集合替代null，降低空指针风险

内容的提问来源于stack exchange，提问作者A R