Spring事务

Spring事务也算是面试中经常遇到的一个小知识点吧，关注的点有以下几个：

 下面简单写点案例，回顾一下；

一、通过配置文件来配置事务  1.导入jar包（这里直接导入了Spring boot相关jar）

    org.springframework.boot
    spring-boot-parent
    2.2.4.RELEASE



    
        org.springframework.boot
        spring-boot-starter-web
        2.2.4.RELEASE
    
    
        org.springframework.boot
        spring-boot-starter-jdbc
    
    
        mysql
        mysql-connector-java
    
    
        io.projectreactor
        reactor-core
        3.4.11
    
    
        aopalliance
        aopalliance
        1.0
    
    
        org.aspectj
        aspectjweaver
        1.8.13
    
    
        org.projectlombok
        lombok
        1.18.22
        provided
    

2.创建用户类

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private int id;
    private String userName;
    private int amount;
}

 3.创建service接口

public interface UserService {
    public User getUser(int id);
    public List getAllUser();
    public boolean delUser(int id);
    public boolean updUser(User user);
    public boolean insertUser(User user);
}

4.创建UserService接口实现类

public class UserServiceImpl implements UserService {

    private JdbcTemplate jdbcTemplate;

    public void setJdbcTemplate(JdbcTemplate jdbcTemplate){
        this.jdbcTemplate = jdbcTemplate;
    }

    public User getUser(int id) {
        return null;
    }
    public List getAllUser() {
        return null;
    }
    public boolean delUser(int id) {
        return false;
    }
    public boolean updUser(User user) {
        return false;
    }
    public boolean insertUser(User user) {
        int insert = jdbcTemplate.update("insert into user(user_name,amount) values(?,?)", "xiaowu", 100);
        int i = 1 / 0;
        return true;
    }
}

5.配置applicationContext.xml配置文件

6.测试

public class ApplicationStart {
    public static void main(String[] args) {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserService userService = ctx.getBean(UserService.class);
        userService.insertUser(new User());
    }
}

 数据插入成功，日志及表数据如下：

修改UserServiceImpl代码如下：

public boolean insertUser(User user) {
    int insert = jdbcTemplate.update("insert into user(user_name,amount) values(?,?)", "xiaowu", 100);
    int i = 1 / 0;
    return true;
}

 再次测试，日志结果如下：

此时表里面也没有新数据插入，事务回滚。 

二、Springboot注解配置事务

1.创建application.properties,配置数据库连接；

spring.datasource.url=jdbc:mysql://localhost:3306/my_db?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf8&useSSL=false
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=123456

 2.修改UserServiceImpl代码如下：

@Transactional(rollbackFor=Exception.class)
public boolean insertUser(User user) {
    int insert = jdbcTemplate.update("insert into user(user_name,amount) values(?,?)", "xiaowu", 100);
    return true;
}

 3.测试

@SpringBootApplication
@EnableTransactionManagement
public class ApplicationStart {
    public static void main(String[] args) {
        ConfigurableApplicationContext context = SpringApplication.run(ApplicationStart.class,args);
        UserService userService = (UserService) context.getBean("userService");
        userService.insertUser(new User());
    }
}

 数据插入成功;

 

 修改UserServiceImpl代码如下：

@Transactional(rollbackFor=Exception.class)
public boolean insertUser(User user) {
    int insert = jdbcTemplate.update("insert into user(user_name,amount) values(?,?)", "xiaowu", 100);
    int i = 1 / 0;
    return true;
}

再次运行，表里面未新增新数据，事务回滚：

 这里在简单测试一下其默认的事务传播机制，修改UserServiceImpl代码如下：

@Service("userService")
public class UserServiceImpl implements UserService {
    @Autowired
    private JdbcTemplate jdbcTemplate;
    @Autowired
    private UserService userService2;
    @Transactional(rollbackFor=Exception.class)
    public boolean insertUser(User user) {
        int insert = jdbcTemplate.update("insert into user(user_name,amount) values(?,?)", "xiaolong", 1100);
        userService2.insertUser(new User());
        return true;
    }
    public User getUser(int id) {
        return null;
    }
    public List getAllUser() {
        return null;
    }
    public boolean delUser(int id) {
        return false;
    }
    public boolean updUser(User user) {
        return false;
    }
}

拷贝一份UserServiceImpl，改名为UserServiceImpl2

@Service("userService2")
public class UserServiceImpl2 implements UserService {
    @Autowired
    private JdbcTemplate jdbcTemplate;
    @Transactional(rollbackFor=Exception.class,propagation= Propagation.REQUIRED)
    public boolean insertUser(User user) {
        int insert = jdbcTemplate.update("insert into user(user_name,amount) values(?,?)", "xiaoqian", 1200);
        int i = 1 / 0;
        return true;
    }
    public User getUser(int id) {
        return null;
    }
    public List getAllUser() {
        return null;
    }
    public boolean delUser(int id) {
        return false;
    }
    public boolean updUser(User user) {
        return false;
    }
}

 运行程序，数据未成功插入，将int i = 1/0;拷贝道UserServiceImpl中

    @Transactional(rollbackFor=Exception.class)
    public boolean insertUser(User user) {
        int insert = jdbcTemplate.update("insert into user(user_name,amount) values(?,?)", "xiaolong", 1100);
        userService2.insertUser(new User());
        int i = 1 / 0;
        return true;
    }

运行效果一样，数据也未插入表中；其它场景也很简单，这里就不做测试了；

总结：Spring事务相对简单，平时写些demo即可，官网里面有一个调用流程的视图，可以简单看看