Java 开发规范

参考来源: Google Java Style Guide、阿里巴巴 Java 开发手册

工具链

# Maven
mvn clean compile                    # 编译
mvn test                             # 运行测试
mvn verify                           # 运行所有检查

# Gradle
./gradlew build                      # 构建
./gradlew test                       # 运行测试

命名约定

类成员顺序

public class Example {
    // 1. 静态常量
    public static final String CONSTANT = "value";

    // 2. 静态变量
    private static Logger logger = LoggerFactory.getLogger(Example.class);

    // 3. 实例变量
    private Long id;

    // 4. 构造函数
    public Example() { }

    // 5. 静态方法
    public static Example create() { return new Example(); }

    // 6. 实例方法（公共 → 私有）
    public void doSomething() { }
    private void helperMethod() { }

    // 7. getter/setter（或使用 Lombok）
}

DTO/VO 类规范

// ❌ 手写 getter/setter
public class UserDTO {
    private Long id;
    private String name;
    public Long getId() { return id; }
    public void setId(Long id) { this.id = id; }
    // ... 大量样板代码
}

// ✅ 使用 Lombok
@Data
public class UserDTO {
    private Long id;
    private String name;
}

批量查询规范

// ❌ 1700 个 ID 一次查询
List<User> users = userRepository.findByIdIn(allIds); // IN 子句过长

// ✅ 分批查询工具方法
public static <T, R> List<R> batchQuery(List<T> params, int batchSize,
                                         Function<List<T>, List<R>> queryFn) {
    List<R> result = new ArrayList<>();
    for (int i = 0; i < params.size(); i += batchSize) {
        List<T> batch = params.subList(i, Math.min(i + batchSize, params.size()));
        result.addAll(queryFn.apply(batch));
    }
    return result;
}

// 使用
List<User> users = batchQuery(allIds, 500, ids -> userRepository.findByIdIn(ids));

N+1 查询防范

// ❌ N+1：循环内逐行查询 count
records.forEach(record -> {
    long count = deviceRepo.countByDeviceId(record.getDeviceId()); // 每条触发一次查询
    record.setDeviceCount(count);
});

// ✅ 循环外批量查询 + Map 查找
List<String> deviceIds = records.stream()
    .map(Record::getDeviceId).distinct().collect(Collectors.toList());
Map<String, Long> countMap = deviceRepo.countByDeviceIdIn(deviceIds).stream()
    .collect(Collectors.toMap(CountDTO::getDeviceId, CountDTO::getCount));
records.forEach(r -> r.setDeviceCount(countMap.getOrDefault(r.getDeviceId(), 0L)));

常见 N+1 场景及修复模式：

并发安全规范

// ❌ read-modify-write 竞态条件
PointsAccount account = accountRepo.findById(id);
account.setBalance(account.getBalance() + points); // 并发时丢失更新
accountRepo.save(account);

// ✅ 方案一：原子更新 SQL
@Modifying
@Query("UPDATE PointsAccount SET balance = balance + :points WHERE id = :id")
int addBalance(@Param("id") Long id, @Param
how to use java-dev
CursorClaude CodeClineCodexWindsurfGooseGitHub CopilotVS CodeGemini CLIKiloOpencodeKimi CLIRoo ClineAiderContinueZedBolt.newLovablev0Replit AgentSweepSmol DeveloperDevinCavemanAmpAntigravity
How to use java-dev on Cursor
AI-first code editor with Composer
1
Prerequisites
Before installing skills in Cursor, ensure your development environment meets these requirements:
›Cursor installed and configured on your development machine
›Node.js version 16.0+ with npm package manager (verify with node --version)
›Active project directory or workspace where you want to add java-dev
2
Execute installation command
Execute the skills CLI command in your project's root directory to begin installation:
$npx skills add https://github.com/doccker/cc-use-exp --skill java-devcopy
The skills CLI fetches java-dev from GitHub repository doccker/cc-use-exp and configures it for Cursor.
3
Select Cursor when prompted
The CLI will show a list of available agents. Use arrow keys to navigate and space to select Cursor:
◆ Which agents do you want to install to?
│
│ ── Universal (.agents/skills) ── always included ────
│   • Amp
│   • Antigravity
│   • Cline
│   • Codex
│ ●Cursor(selected)
│   • Cursor
│   • Windsurf
4
Verify installation
Confirm successful installation by checking the skill directory location:
.cursor/skills/java-dev
Reload or restart Cursor to activate java-dev. Access the skill through slash commands (e.g., /java-dev) or your agent's skill management interface.
⚠
Security & Verification Notice
We perform automated surface-level scans (Gen AI Scanner, Socket, Snyk) during installation. These checks detect common vulnerabilities but do not guarantee complete security. Always review skill source code and verify the publisher's reputation before production use.
Skills execute code in your development environment. Always verify the publisher's identity, review recent commits, and test in isolated environments before production deployment.
Additional Resources
›View source code on GitHub›Skills CLI documentation›Learn more about Cursor›What are agent skills?