@EnableTransactionManagement

@Configuration
@EnableTransactionManagement(proxyTargetClass = true, order = 1)
public class TransactionConfig {
    // ...
}

package com.feixiang.config;

import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.sql.DataSource;

@Configuration
@ComponentScan("com.feixiang")
@EnableTransactionManagement(proxyTargetClass = true)  // 开启注解事务管理，强制 CGLIB 代理
public class AppConfig {

    @Bean
    public DataSource dataSource() {
        HikariConfig config = new HikariConfig();
        config.setJdbcUrl("jdbc:mysql://localhost:3306/feixiang_tools?useSSL=false&serverTimezone=Asia/Shanghai");
        config.setUsername("root");
        config.setPassword("secret");
        config.setMaximumPoolSize(5);
        return new HikariDataSource(config);
    }

    @Bean
    public JdbcTemplate jdbcTemplate(DataSource dataSource) {
        return new JdbcTemplate(dataSource);
    }

    @Bean
    public PlatformTransactionManager transactionManager(DataSource dataSource) {
        // 注册基于 JDBC 的事务管理器
        return new DataSourceTransactionManager(dataSource);
    }
}

package com.feixiang.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service
public class ToolRentalService {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Transactional
    public void rentTool(int employeeId, int toolId) {
        // 1. 检查工具是否可用
        Integer available = jdbcTemplate.queryForObject(
            "SELECT available FROM tool_inventory WHERE tool_id = ?",
            Integer.class, toolId
        );
        if (available == null || available <= 0) {
            throw new IllegalStateException("工具已被借完，ID：" + toolId);
        }

        // 2. 扣减库存
        jdbcTemplate.update(
            "UPDATE tool_inventory SET available = available - 1 WHERE tool_id = ?",
            toolId
        );
        System.out.println("[工具借用] 库存已扣减，工具：" + toolId);

        // 3. 插入借用记录
        jdbcTemplate.update(
            "INSERT INTO tool_rental (employee_id, tool_id, status) VALUES (?, ?, 'RENTED')",
            employeeId, toolId
        );
        System.out.println("[工具借用] 记录已创建，员工：" + employeeId);

        // 4. 模拟异常，验证回滚
        if (toolId == 9999) {
            throw new RuntimeException("模拟系统异常，验证事务回滚");
        }
    }
}

package com.feixiang;

import com.feixiang.config.AppConfig;
import com.feixiang.service.ToolRentalService;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class EnableTxTest {
    public static void main(String[] args) {
        // 使用纯 Java Config 启动 Spring 容器
        AnnotationConfigApplicationContext ctx =
            new AnnotationConfigApplicationContext(AppConfig.class);
        ToolRentalService service = ctx.getBean(ToolRentalService.class);

        // 验证代理类型
        System.out.println("Service 实际类型：" + service.getClass().getName());

        // 场景一：正常借用
        try {
            service.rentTool(1001, 1001);
            System.out.println("[场景一] 借用成功");
        } catch (Exception e) {
            System.err.println("[场景一] 借用失败：" + e.getMessage());
        }

        // 场景二：触发异常，验证回滚
        try {
            service.rentTool(1002, 9999);
            System.out.println("[场景二] 借用成功");
        } catch (Exception e) {
            System.err.println("[场景二] 借用失败：" + e.getMessage());
        }

        ctx.close();
    }
}

@Configuration
@ComponentScan("com.feixiang")
// 错误：缺少 @EnableTransactionManagement
public class AppConfig {

    @Bean
    public PlatformTransactionManager transactionManager(DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
}

@Service
public class OrderService {

    @Transactional  // 该注解被完全忽略！
    public void createOrder() {
        // ...
    }
}

@Configuration
@EnableTransactionManagement
public class AppConfig {

    @Bean
    public DataSource dataSource() {
        // ...
    }

    // 错误：忘记注册 PlatformTransactionManager
    // Spring 启动时会抛出 NoSuchBeanDefinitionException
}

@SpringBootApplication
@EnableTransactionManagement  // 冗余，Spring Boot 已自动配置
public class FeixiangApplication {
    public static void main(String[] args) {
        SpringApplication.run(FeixiangApplication.class, args);
    }
}