简单介绍Spring中的事物

事务：

事物作用：在数据层保障一系列的数据库操作同成功同失败。

Spring事务作用：在数据层或业务层保障一系列的数据库操作同成功同失败。

事务角色：

•         事务管理员：发起事务方，在Spring中通常指代业务层开启事务的方法。
•         事务协调员：加入事务方，在Spring中通常指代数据层方法，也可以是业务层方法。

 事务传播行为：

例：@Transactional(propagation = Propagation.REQUIRES_NEW)

事务相关配置：

程序在error时候和运行时异常会发生回滚，有些异常默认不参与回滚，需要加条件。

例如：@Transactional(rollbackFor = {IOException.class})

 代码实现：

config包

JdbcConfig.java

package com.it.config;
 
import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
 
import javax.sql.DataSource;
 
 
public class JdbcConfig {
    @Value("${jdbc.driver}")
    private String driver;
    @Value("${jdbc.url}")
    private String url;
    @Value("${jdbc.username}")
    private String username;
    @Value("${jdbc.password}")
    private String password;
 
    @Bean
    public DataSource dataSource(){
        DruidDataSource ds = new DruidDataSource();
        ds.setDriverClassName(driver);
        ds.setUrl(url);
        ds.setUsername(username);
        ds.setPassword(password);
        return ds;
    }
 
    @Bean
    public PlatformTransactionManager transactionManager(DataSource dataSource){
        DataSourceTransactionManager transactionManager = new DataSourceTransactionManager();
        transactionManager.setDataSource(dataSource);
        return transactionManager;
    }
}

Mybatis.java

package com.it.config;
 
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.context.annotation.Bean;
 
import javax.sql.DataSource;
 
public class MybatisConfig {
 
    @Bean
    public SqlSessionFactoryBean sqlSessionFactory(DataSource dataSource){
 
        SqlSessionFactoryBean ssfb = new SqlSessionFactoryBean();
        ssfb.setTypeAliasesPackage("com.it.domain");
        ssfb.setDataSource(dataSource);
        return ssfb;
    }
 
    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer(){
        MapperScannerConfigurer msc = new MapperScannerConfigurer();
        msc.setBasePackage("com.it.dao");
        return msc;
    }
 
}

SpringConfig.java:

package com.it.config;
 
 
import org.springframework.context.annotation.*;
import org.springframework.transaction.annotation.EnableTransactionManagement;
 
@Configuration
@ComponentScan("com.it")
@PropertySource("classpath:jdbc.properties")
@Import({JdbcConfig.class,MybatisConfig.class})
@EnableTransactionManagement //事务注解
public class SpringConfig {
}

dao包：

AccountDao.java:

package com.it.dao;
 
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Update;
 
public interface AccountDao {
    @Update("update acc set money = money + #{money} where name = #{name}")
    void inMoney(@Param("name") String name, @Param("money") Double money);
 
    @Update("update acc set money = money - #{money} where name = #{name}")
    void outMoney(@Param("name") String name, @Param("money") Double money);
}

 LogDao.java

package com.it.dao;
 
import org.apache.ibatis.annotations.Insert;
 
public interface LogDao {
    @Insert("insert into acc_log (info,createDate) values(#{info},now())")
    void log(String info);
}

service包：

        impl包：

                AccountServiceImpl.java:

                

package com.it.service.impl;
 
import com.it.dao.AccountDao;
import com.it.service.AccountService;
import com.it.service.LogService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
@Service
public class AccountServiceImpl implements AccountService {
 
    @Autowired
    private AccountDao accountDao;
 
    @Autowired
    private LogService logService;
 
    public void transfer(String out,String in,Double money){
        try{
            accountDao.outMoney(out,money);
            accountDao.inMoney(in,money);
        }
        finally {
            logService.log(out,in,money);
        }
 
 
    }
}

                LogServiceImpl.java:

        

package com.it.service.impl;
 
import com.it.dao.LogDao;
import com.it.service.LogService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
@Service
public class LogServiceImpl implements LogService {
 
    @Autowired
    private LogDao logDao;
 
    public void log(String out, String in, Double money) {
        logDao.log("转账由"+out+"到"+in+"金额"+money);
    }
}

AccountService.java:

package com.it.service;
 
import org.springframework.transaction.annotation.Transactional;
 
public interface AccountService {
    /**
     * 转账操作
     * @param out 转出
     * @param in  转入
     * @param money  金额
     */
    @Transactional //开启事务
    public void transfer(String out, String in, Double money);
}

LogService.java

package com.it.service;
 
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
 
public interface LogService {
    @Transactional(propagation = Propagation.REQUIRES_NEW) //开辟新事物
    void log(String out,String in,Double money);
}

Test:

test.java:

package com.it;
 
import com.it.config.SpringConfig;
import com.it.service.AccountService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
import java.io.IOException;
 
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = SpringConfig.class)
public class AccountTest{
 
    @Autowired
    private AccountService accountService;
 
    @Test
    public void testTransfer() throws IOException{
        accountService.transfer("zhangsan","lisi",50D);
    }
}