@Transactional不工作时，@自动安装应用

Question

我编写了一个示例应用程序来测试Spring中的注释事务管理（@Transactional）。

上下文文件；

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">

<tx:annotation-driven />

<context:component-scan base-package="com.test" /> 

<bean id="playerService" class="com.test.service.PlayerServiceImpl" />

<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
    <property name="dataSource" ref="dataSource" />
</bean>

<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource" />
</bean>

<bean id="dbUtil" class="com.test.util.DbUtil" init-method="initialize">
    <property name="dataSource" ref="dataSource" />
</bean>

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="${jdbc.driverClassName}" />
    <property name="url" value="${jdbc.url}" />
    <property name="username" value="${jdbc.username}" />
    <property name="password" value="${jdbc.password}" />
</bean>

<context:property-placeholder location="jdbc.properties"/>

菜豆

import com.test.model.Player;
import com.test.model.Team;

public interface PlayerDao {

public void insertPlayer(Player player);

public void insertTeam(Team team);

}

PlayerDaoImpl的实现

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

import com.test.model.Player;
import com.test.model.Team;

@Repository
public class PlayerDaoImpl implements PlayerDao{ 

    private JdbcTemplate jdbcTemplate;

    @Autowired
    public void setDataSource(DataSource dataSource) {
        this.jdbcTemplate = new JdbcTemplate(dataSource);
    }

    @Transactional (propagation=Propagation.REQUIRED)
    public void insertPlayer(Player player){
        String insertSql ="INSERT INTO PLAYERS (PLAYER_NAME, DOB, AGE, TEAM_ID) VALUES(?,?,?,?);";

        jdbcTemplate.update(insertSql,new Object[]{player.getPlayerName(),player.getDob(), player.getAge(), player.getTeamId()});
    }

    @Transactional (propagation=Propagation.REQUIRED)
    public void insertTeam(Team team){
        String insertSql ="INSERT INTO TEAMS (TEAM_ID, TEAM_NAME) VALUES(?,?);";

        jdbcTemplate.update(insertSql,new Object[]{team.getTeamId(),team.getTeamName()});
    }

}

玩家服务

import com.test.model.Team;

public interface PlayerService {
    public void createTeam1(Team team) throws Exception;
    public void createTeam2(Team team) throws Exception;
}

PlayerService实现

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.test.model.Team;
import com.test.persistence.PlayerDao;

@Service
public class PlayerServiceImpl implements PlayerService{

    @Autowired
    private  PlayerDao playerDao;

    public void createTeam1(Team team) throws Exception{
        playerDao.insertPlayer(team.getPlayers().get(0));
        playerDao.insertPlayer(team.getPlayers().get(1));
        playerDao.insertPlayer(team.getPlayers().get(2));
        playerDao.insertTeam(team);
    }

    public void createTeam2(Team team) throws Exception{
        playerDao.insertPlayer(team.getPlayers().get(0));
        playerDao.insertPlayer(team.getPlayers().get(1));

        playerDao.insertTeam(team);
        throw new Exception();
    }
}

主要班级；

import java.time.LocalDate;
import java.util.ArrayList;
import java.util.List;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.test.model.Player;
import com.test.model.Team;
import com.test.service.PlayerService;

public class TestMain {



    public static void main(String[] args) {

        ApplicationContext context = new ClassPathXmlApplicationContext("spring-config.xml");
        PlayerService playerService = (PlayerService) context.getBean("playerService");

        Team t1 = new Team();

        t1.setTeamId(1);
        t1.setTeamName("Team-1");

        Player p1 = new Player("Player 1", LocalDate.of(1981,05,02), 1);        
        Player p2 = new Player("Player 2", LocalDate.of(1983,02,15), 1);
        Player p3 = new Player("Player 3", LocalDate.of(1980,12,31), 1);

        List<Player> players1 = new ArrayList<Player>();
        players1.add(p1);
        players1.add(p2);
        players1.add(p3);

        t1.setPlayers(players1);

        Team t2 = new Team();

        t2.setTeamId(2);
        t2.setTeamName("Team-2");

        Player p4 = new Player("Player 4", LocalDate.of(1989,05,02), 1);
        Player p5 = new Player("Player 5", null, 1);

        List<Player> players2 = new ArrayList<Player>();
        players2.add(p4);
        players2.add(p5);

        t2.setPlayers(players2);

        try {
            playerService.createTeam1(t1);
            playerService.createTeam2(t2);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

当我在上下文文件中将playerDao设置为PlayerService的属性之一时，事务运行良好，如下所示（playerDao没有@Autowired set）；

<bean id="playerService" class="com.slpl.service.PlayerServiceImpl" >
    <property name="playerDao" ref="playerDao" />
</bean>

<bean id="playerDao" class="com.slpl.persistence.PlayerDaoImpl">
    <property name="jdbcTemplate" ref="jdbcTemplate" />
</bean>

但是，当I@Autowired playerDao连接到PlayerServiceImpl类时，事务不适用（事务不起作用）。

我犯了什么错？

Answer 1

这个示例应用程序将演示使用注释的Spring事务。PlayerServiceImpl类中的createTeam1（）方法将创建3名玩家和一个团队。因此，一旦完成运行，它将在PLAYERS表中创建3行，在TEAMS表中创建一行。createTeam2（）方法试图创建两个玩家和一个团队。在这个方法的末尾，它抛出一个异常，该异常应该回滚玩家和团队创建，并且不能在玩家和团队表中创建行。

对于PlayerServiceImpl类中的PlayerDao，使用@Autowired注释是正确的。然而，申请交易是不正确的。正如@M.Deinum清楚解释的，当前代码通过直接在DAO方法（在本例中是insertPlayer（）和insertTeam（）方法）中应用事务来创建7个单独的事务。因此，应用事务的正确方法是在服务方法（本例中为createTeam1（）和createTeam2（）方法）上。

为了在抛出异常时回滚事务，必须使用正确的异常设置rollbackfor事务属性（作为@Transactional注释的属性）。然后在抛出异常时弹出事务回滚更改。因此，正确的服务方法实现如下；

@Transactional (propagation=Propagation.REQUIRED, rollbackFor = {Exception.class})
public void createTeam1(Team team) throws Exception{
    playerDao.insertPlayer(team.getPlayers().get(0));
    playerDao.insertPlayer(team.getPlayers().get(1));
    playerDao.insertPlayer(team.getPlayers().get(2));
    playerDao.insertTeam(team);
}

@Transactional (propagation=Propagation.REQUIRED, rollbackFor = {Exception.class})
public void createTeam2(Team team) throws Exception{
    playerDao.insertPlayer(team.getPlayers().get(0));
    playerDao.insertPlayer(team.getPlayers().get(1));

    playerDao.insertTeam(team);
    throw new Exception();
}