Clean Code Practices: Naming, Method Length, Nesting Reduction, and Useful Libraries

Code as a Team Communication Tool

Beyond emails and face‑to‑face talks, code itself conveys design intent; clear structure and good comments let teammates understand and maintain features without constant clarification.

Keep the Camp Cleaner Than When You Arrived

Just as scouts clean their campsite, developers should follow established coding standards and reuse shared libraries instead of introducing redundant or conflicting implementations.

Appropriate Naming

Good names are as crucial as naming a newborn. Teams should agree on domain‑specific terms (e.g., using canteen consistently) and avoid misleading abbreviations.

Bad Example

// 手机号
String phone = "13421800409";
// 获取地址
private String getDiZhi();
//修改密码
private void modifyPassword(String password1 ,String password2)

Good Example

// 手机号 mobileNo比phone更精确
String mobileNo = "13421800409";
// 避免英文拼音混杂
private String getAddress();
// 参数的命名要区分意义
private void modifyPassword(String oldPassowrd, String newPassword)

Short Methods

Methods should be concise; extremely long methods (e.g., 500 lines) hinder readability. Split complex logic into smaller, focused methods.

Bad Example

private UserDTO getUserDTO(Integer userId) {
    //获取基本信息 …10行
    //获取最近的一次订单信息 …30行
    //获取钱包、可用优惠券张数等 …30行
    return userDTO;
}

Good Example

private UserDTO getUserDTO(Integer userId) {
    UserDTO userDTO = getUserBasicInfo(userId);
    userDTO.setUserLastOrder(getUserLastOrder(userId));
    userDTO.setUserAccount(getUserAccount(userId));
    return userDTO;
}
private UserDTO getUserBasicInfo(Integer userId);
private UserLastOrder getUserLastOrder(Integer userId);
private UserAccount getUserAccount(Integer userId);

Reduce if/else Nesting

Deep nesting makes code hard to follow. Guard clauses (early returns) simplify the flow.

Bad Example

public boolean modifyPassword(Integer userId, String oldPassword, String newPassword) {
    if (userId != null && StringUtils.isNotBlank(newPassword) && SpringUtils.isNotBlank(oldPassword)) {
        User user = getUserById(userId);
        if (user != null) {
            if (user.getPassword().equals(oldPassword)) {
                return updatePassword(userId, newPassword);
            }
        }
    }
    return false;
}

Good Example

public Boolean modifyPassword(Integer userId, String oldPassword, String newPassword) {
    if (userId == null || StringUtils.isBlank(newPassword) || StringUtils.isBlank(oldPassword)) {
        return false;
    }
    User user = getUserById(userId);
    if (user == null) {
        return false;
    }
    if (!user.getPassword().equals(oldPassword)) {
        return false;
    }
    return updatePassword(userId, newPassword);
}

Extract try/catch

Long methods wrapped in a single try/catch hide where errors occur. Isolate risky operations into separate methods with their own handling.

Bad Example

private UserDTO getUserDTO(Integer userId) {
    try {
        // many lines ...
    } catch (Exception e) {
        logger.error(e);
        return null;
    }
    return userDTO;
}

Good Example

private UserDTO getUserDTO(Integer userId) {
    UserDTO userDTO = getUserBasicInfo(userId);
    userDTO.setUserLastOrder(getUserLastOrder(userId));
    userDTO.setUserAccount(getUserAccount(userId));
    return userDTO;
}
private UserDTO getUserBasicInfo(Integer userId) { /* ... */ }
private UserLastOrder getUserLastOrder(Integer userId) { /* ... */ }
private UserAccount getUserAccount(Integer userId) {
    try {
        // TODO
    } catch (Exception e) {
        // TODO
    }
}

Encapsulate Multiple Parameters

If a method needs more than three arguments, wrap them in a DTO to avoid long signatures and improve readability.

Bad Example

public Page<Order> queryOrderByPage(Integer current, Integer size, String productName, Integer userId, Date startTime, Date endTime, BigDecimal minAmount, BigDecimal maxAmount) { }

Good Example

@Getter @Setter
public class OrderQueryDTO extends PageDTO {
    private String productName;
    private Integer userId;
    private Date startTime;
    private Date endTime;
    private BigDecimal minAmount;
    private BigDecimal maxAmount;
}
public Page<Order> queryOrderByPage(OrderQueryDTO orderQueryDTO) { }

Third‑Party Libraries

Lombok

Lombok generates constructors, getters/setters, equals, hashCode, and toString methods at compile time via annotations.

@Getter @Setter
public class Order {
    private Integer userId;
}

Apache Commons

Apache Commons provides utilities for collections, strings, IO, etc.

// Example: check if a collection is empty
CollectionUtils.isEmpty(null); // true
CollectionUtils.isEmpty(new ArrayList()); // true
CollectionUtils.isEmpty(Arrays.asList("a", "b")); // false

(End of article)