<!-- 項(xiàng)目坐標(biāo)：唯一標(biāo)識(shí)一個(gè)Maven項(xiàng)目 -->
<groupId>com.company.project</groupId>
<artifactId>demo-service</artifactId>
<version>1.0.0</version>
<packaging>jar</packaging> <!-- 打包類型：jar/war/pom -->
<!-- 依賴管理 -->
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <version>3.2.0</version>
    </dependency>
</dependencies>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    <exclusions>
        <exclusion>
            <groupId>logback-classic</groupId>
            <artifactId>ch.qos.logback</artifactId>
        </exclusion>
    </exclusions>
</dependency>

<bean id="userService" class="com.demo.service.UserService">
    <property name="userMapper" ref="userMapper"/>
</bean>

@Service
public class UserService {
    private final UserMapper userMapper;
    @Autowired // Spring 4.3+可省略
    public UserService(UserMapper userMapper) {
        this.userMapper = userMapper;
    }
}

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-aop</artifactId>
</dependency>

@Aspect
@Component
public class LogAspect {
    // 切入點(diǎn)：匹配所有service方法
    @Pointcut("execution(* com.demo.service.*.*(..))")
    public void servicePointcut() {}
    // 前置通知
    @Before("servicePointcut()")
    public void before(JoinPoint joinPoint) {
        String method = joinPoint.getSignature().getName();
        System.out.println("方法" + method + "開始執(zhí)行");
    }
    // 環(huán)繞通知
    @Around("servicePointcut()")
    public Object around(ProceedingJoinPoint pjp) throws Throwable {
        long start = System.currentTimeMillis();
        Object result = pjp.proceed(); // 執(zhí)行目標(biāo)方法
        long time = System.currentTimeMillis() - start;
        System.out.println("方法執(zhí)行耗時(shí)：" + time + "ms");
        return result;
    }
}

# 服務(wù)器配置
server:
  port: 8080
  servlet:
    context-path: /demo
# 數(shù)據(jù)庫(kù)配置
spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/test?useSSL=false
    username: root
    password: 123456
# 自定義配置
app:
  name: demo-app
  version: 1.0.0
  features:
    - log
    - security

@RestController
public class AppController {
    @Value("${app.name}")
    private String appName;
}

@Autowired
private Environment env;
public String getAppVersion() {
    return env.getProperty("app.version");
}

@Component
@ConfigurationProperties(prefix = "app")
public class AppConfig {
    private String name;
    private String version;
    private List<String> features;
    // getter/setter
}

@Service
public class ScheduledService {
    // 每5秒執(zhí)行一次
    @Scheduled(fixedRate = 5000)
    public void fixedRateTask() {
        System.out.println("固定頻率任務(wù)執(zhí)行：" + new Date());
    }
    // 每天凌晨2點(diǎn)執(zhí)行
    @Scheduled(cron = "0 0 2 * * ?")
    public void cronTask() {
        System.out.println("定時(shí)任務(wù)執(zhí)行：" + new Date());
    }
}

public class CronValidator {
    public static void main(String[] args) throws ParseException {
        String cron = "0 0 2 * * ?";
        CronExpression exp = new CronExpression(cron);
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Date now = new Date();
        // 打印未來5次執(zhí)行時(shí)間
        for (int i = 0; i < 5; i++) {
            now = exp.getNextValidTimeAfter(now);
            System.out.println(sdf.format(now));
        }
    }
}

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper-spring-boot-starter</artifactId>
    <version>2.0.1</version>
</dependency>

public PageInfo<User> getUserPage(int pageNum, int pageSize) {
    // 設(shè)置分頁(yè)參數(shù)
    PageHelper.startPage(pageNum, pageSize);
    // 執(zhí)行查詢
    List<User> users = userMapper.selectAll();
    // 封裝分頁(yè)結(jié)果
    return new PageInfo<>(users);
}

<select id="selectUserByCondition" resultType="User">
    SELECT * FROM user
    <where>
        <if test="name != null and name != ''">
            AND name LIKE concat('%', #{name}, '%')
        </if>
        <if test="age != null">
            AND age = #{age}
        </if>
        <if test="ids != null and ids.size() > 0">
            AND id IN
            <foreach collection="ids" item="id" open="(" close=")" separator=",">
                #{id}
            </foreach>
        </if>
    </where>
</select>

<!-- 定義SQL片段 -->
<sql id="userColumns">
    id, name, age, create_time, update_time
</sql>
<!-- 引用SQL片段 -->
<select id="selectUserById" resultType="User">
    SELECT <include refid="userColumns"/> FROM user WHERE id = #{id}
</select>

@RestControllerAdvice // 全局異常處理器
public class GlobalExceptionHandler {
    // 處理業(yè)務(wù)異常
    @ExceptionHandler(BusinessException.class)
    public Result<?> handleBusinessException(BusinessException e) {
        return Result.fail(e.getCode(), e.getMessage());
    }
    // 處理系統(tǒng)異常
    @ExceptionHandler(Exception.class)
    public Result<?> handleSystemException(Exception e) {
        log.error("系統(tǒng)異常", e);
        return Result.fail(500, "系統(tǒng)繁忙，請(qǐng)稍后再試");
    }
}
// 自定義業(yè)務(wù)異常
public class BusinessException extends RuntimeException {
    private Integer code;
    public BusinessException(Integer code, String message) {
        super(message);
        this.code = code;
    }
    // getter
}
// 統(tǒng)一響應(yīng)結(jié)果
public class Result<T> {
    private Integer code;
    private String message;
    private T data;
    // 成功/失敗靜態(tài)方法
    public static <T> Result<T> success(T data) {
        Result<T> result = new Result<>();
        result.setCode(200);
        result.setMessage("success");
        result.setData(data);
        return result;
    }
    public static <T> Result<T> fail(Integer code, String message) {
        // 實(shí)現(xiàn)省略
    }
}

@RestController
@RequestMapping("/user")
@CrossOrigin(origins = "http://localhost:8081", maxAge = 3600)
public class UserController {
    // 接口實(shí)現(xiàn)
}

@Configuration
public class CorsConfig implements WebMvcConfigurer {
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**") // 所有路徑
                .allowedOrigins("http://localhost:8081") // 允許的源
                .allowedMethods("GET", "POST", "PUT", "DELETE") // 允許的方法
                .allowedHeaders("*") // 允許的請(qǐng)求頭
                .allowCredentials(true) // 允許攜帶cookie
                .maxAge(3600); // 預(yù)檢請(qǐng)求緩存時(shí)間
    }
}

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <optional>true</optional>
</dependency>

@Data // 包含getter、setter、toString、equalsAndHashCode、RequiredArgsConstructor
@NoArgsConstructor
@AllArgsConstructor
@TableName("user") // MyBatis-Plus表名注解
public class User {
    @TableId(type = IdType.AUTO)
    private Long id;
    private String name;
    private Integer age;
    @TableField(fill = FieldFill.INSERT)
    private LocalDateTime createTime;
    @TableField(fill = FieldFill.INSERT_UPDATE)
    private LocalDateTime updateTime;
}

<dependency>
    <groupId>org.springdoc</groupId>
    <artifactId>springdoc-openapi-starter-webmvc-ui</artifactId>
    <version>2.3.0</version>
</dependency>

@Configuration
public class SwaggerConfig {
    @Bean
    public OpenAPI customOpenAPI() {
        return new OpenAPI()
                .info(new Info()
                        .title("Demo API")
                        .version("1.0")
                        .description("接口文檔"));
    }
}