從普通到優秀！Java 資深開發者是如何審查代碼的？
作者：路條編程
在這篇文章中，我們將一起進行幾次代碼審查，同時學習在審查時需要關注哪些問題。還會討論如何以專業且尊重的態度參與代碼審查。
在這篇文章中，我們將一起進行幾次代碼審查，同時學習在審查時需要關注哪些問題。還會討論如何以專業且尊重的態度參與代碼審查。
話不多說，讓我們開始吧！
審查1：發現常見錯誤
在審查任何代碼時，我首先關注有沒有一些常見但容易被忽視的錯誤。
來看下面這段代碼，找找其中的問題：
package com.icoderoad.order;
import java.util.List;
public class OrderProcessor {
private final List<Order> orders;
public OrderProcessor(List<Order> orders) {
this.orders = orders;
}
public void processOrders() {
for (Order order : orders) {
if ("Paid".equals(order.getOrderStatus())) {
order.setOrderStatus("Shipped");
System.out.println("Order " + order.getOrderId() + " is now Shipped.");
} else if ("Shipped".equals(order.getOrderStatus())) {
order.setOrderStatus("Completed");
System.out.println("Order " + order.getOrderId() + " is now Completed.");
}
}
}
}
class Order {
private int orderId;
private String orderStatus;
private double totalAmount;
// getters and setters
}你發現什么問題了嗎？沒錯！這段代碼存在：
- 缺少異常處理（沒有 try-catch）
- 硬編碼字符串（"Paid"、"Shipped"）
- 命名風格不統一（
orderIdvsorderStatusvstotalAmount）
修正后的版本：
package com.icoderoad.order;
import java.util.List;
public class OrderProcessor {
private final List<Order> orders;
public OrderProcessor(List<Order> orders) {
this.orders = orders;
}
public void processOrders() {
for (Order order : orders) {
try {
switch (order.getStatus()) {
case PAID -> {
order.setStatus(OrderStatus.SHIPPED);
System.out.println("Order " + order.getId() + " is now Shipped.");
}
case SHIPPED -> {
order.setStatus(OrderStatus.COMPLETED);
System.out.println("Order " + order.getId() + " is now Completed.");
}
default -> System.out.println("Order " + order.getId() + " has an unknown status: " + order.getStatus());
}
} catch (Exception ex) {
System.err.println("Error processing order " + order.getId() + ": " + ex.getMessage());
}
}
}
}
package com.icoderoad.order;
public class Order {
private int id;
private OrderStatus status;
private double totalAmount;
// getters and setters
}
package com.icoderoad.order;
public enum OrderStatus {
PAID,
SHIPPED,
COMPLETED
}審查2：遺漏空值檢查（Null Check）
再來看這段：
package com.icoderoad.customer;
import java.util.List;
public class OrderProcessor {
public void getCustomerOrderDetails(Customer customer) {
if (customer.getOrders().size() > 0) {
for (Order order : customer.getOrders()) {
System.out.println("Order ID: " + order.getId() + ", Amount: " + order.getAmount());
}
} else {
System.out.println("No orders found.");
}
}
}發現問題了嗎？正確！這里缺少空值檢查，如果 customer 或 orders 為 null，就直接崩潰了！
修正后的版本：
package com.icoderoad.customer;
import java.util.List;
public class OrderProcessor {
public void getCustomerOrderDetails(Customer customer) {
if (customer == null) {
System.out.println("Customer is null.");
return;
}
List<Order> orders = customer.getOrders();
if (orders == null || orders.isEmpty()) {
System.out.println("No orders found.");
return;
}
for (Order order : orders) {
System.out.println("Order ID: " + order.getId() + ", Amount: " + order.getAmount());
}
}
}審查3：強耦合（Tight Coupling）
繼續看：
package com.icoderoad.order;
public class OrderService {
private final PaymentService paymentService = new PaymentService();
public void processOrder(Order order) {
paymentService.processPayment(order);
}
}沒錯，這是強耦合設計！OrderService 直接綁定了具體實現，難以測試和擴展。
更好的方式：使用接口 + 構造器注入（Dependency Injection）
package com.icoderoad.order;
public class OrderService {
private final IPaymentService paymentService;
public OrderService(IPaymentService paymentService) {
this.paymentService = paymentService;
}
public void processOrder(Order order) {
paymentService.processPayment(order);
}
}審查4：神秘數字（Magic Numbers）
你的朋友寫了稅率邏輯：
package com.icoderoad.tax;
public class TaxCalculator {
public double calculateTax(double income) {
if (income <= 50000) return income * 0.10;
if (income <= 100000) return income * 0.15;
if (income <= 200000) return income * 0.20;
return income * 0.30;
}
}這里有大量魔法數字，后期改動會非常痛苦。
更好的設計：
package com.icoderoad.tax;
import java.util.List;
public class TaxCalculator {
private final List<Double> incomeSlabs;
private final List<Double> taxRates;
public TaxCalculator(List<Double> incomeSlabs, List<Double> taxRates) {
this.incomeSlabs = incomeSlabs;
this.taxRates = taxRates;
}
public double calculateTax(double income) {
for (int i = 0; i < incomeSlabs.size(); i++) {
if (income <= incomeSlabs.get(i)) {
return income * taxRates.get(i);
}
}
return income * taxRates.get(taxRates.size() - 1);
}
}配合配置文件或常量管理，維護性更高！
審查5：別重復你自己（DRY）
看下面的代碼：
package com.icoderoad.discount;
public class DiscountCalculator {
public double calculateDiscount(double amount, double discountPercentage) {
double discount = amount * discountPercentage;
return amount - discount;
}
public double applyDiscount(double amount, double discountPercentage) {
double discount = amount * discountPercentage;
return amount - discount;
}
}這里明顯重復了邏輯！
正確版本：
package com.icoderoad.discount;
public class DiscountCalculator {
public double calculateDiscount(double amount, double discountPercentage) {
return applyDiscount(amount, discountPercentage);
}
public double applyDiscount(double amount, double discountPercentage) {
return amount - calculateDiscountAmount(amount, discountPercentage);
}
private double calculateDiscountAmount(double amount, double discountPercentage) {
return amount * discountPercentage;
}
}審查6：YAGNI原則（You Aren’t Gonna Need It）
最后，來看這段帶優惠券處理的代碼：
package com.icoderoad.order;
public class OrderProcessor {
public void processOrder(Order order, double discount) {
double discountAmount = order.getAmount() * discount;
double finalAmount = order.getAmount() - discountAmount;
System.out.println("Discount Applied: " + discountAmount);
if (order.getCouponCode() != null) {
double couponDiscount = applyCoupon(order.getCouponDiscount());
finalAmount -= couponDiscount;
System.out.println("Coupon " + order.getCouponCode() + " applied.");
}
}
private double applyCoupon(double couponDiscount) {
return couponDiscount;
}
}問題在于：需求只要做折扣，卻提前加了優惠券邏輯，增加了不必要復雜性！
遵循 YAGNI 原則：只做需求中需要的內容。
精簡版：
package com.icoderoad.order;
public class OrderProcessor {
public void processOrder(Order order, double discount) {
double discountAmount = order.getAmount() * discount;
double finalAmount = order.getAmount() - discountAmount;
System.out.println("Discount Applied: " + discountAmount);
}
}總結
一個優秀的 Java 開發者，在代碼審查時應該特別關注：
- 是否有異常處理和日志
- 命名風格是否統一
- 是否避免了魔法數字
- 是否做了空值檢查
- 是否違反 DRY 原則
- 是否提前開發了無關功能（YAGNI）
- 是否有合理的接口隔離和依賴注入設計
審代碼，不止是挑刺，更是讓團隊代碼整體更健康、更易維護！
責任編輯：武曉燕
來源：
路條編程
