java - 事务不会回滚@Hibernate

Question

我正在尝试为我的 spring 项目添加一个回滚机制，按照一些教程我仍然无法解决为什么回滚不会在以下代码中发生的问题:

@Override
    @Transactional(propagation = Propagation.REQUIRED, rollbackFor = TransactionException.class)
    public boolean changeSquad(ArrayList<Integer> playerIdList, String email) {
        boolean squadChanged = false;

        // Obtain the current list of players from the persistent storage
        TypedQuery<Player> playersQuery = emgr.createNamedQuery("Player.getUsersPlayers", Player.class);
        playersQuery.setParameter("email", email);



        List<Player> currentPlayerList = playersQuery.getResultList();

        // Make a copy of the list obtained as method parameter
        ArrayList<Integer> playerIdListCopy = new ArrayList<Integer>(playerIdList);

        // Make a copy of the list obtained from persistent storage
        ArrayList<Player> currentPlayerListCopy = new ArrayList<Player>(currentPlayerList);
        System.out.println("current player list copy = " + currentPlayerListCopy);



        // Iterate through each player from the currentPlayerList
        for (int i = 0; i < currentPlayerListCopy.size(); i++) {
            // On each iteration check if the playerIdList contains currently iterated 
            // Player's id, if so then eliminate it from both lists
            int playerId = currentPlayerListCopy.get(i).getPlayer_id();

            if (playerIdListCopy.contains(playerId)) {
                currentPlayerListCopy.remove(i);
                playerIdListCopy.remove(playerIdListCopy.indexOf(playerId));
                i--;
            }

        }
        // IF copy of current player list AND playerId list is empty, proceed
        if (currentPlayerListCopy.isEmpty() && playerIdListCopy.isEmpty()) {
            System.out.println("currentPlayerListCopy && playerIdListCopy = empty");

            // Make the squad changes

            for (int j = 0; j < currentPlayerList.size(); j++) {
                Player tempPlayer = currentPlayerList.get(j);
                int tempPlayerId = tempPlayer.getPlayer_id();

                // LOOP for all players from the client side list
                for (int n = 0; n < playerIdList.size(); n++) {
                    if (playerIdList.get(n) == tempPlayerId) {
                        ......
                    } 
                } // END loop for all players from the client side list 

                emgr.persist(tempPlayer);
                if (j == 13) {
                    System.out.println("j13, throwing exception");
                    try {
                        throw new TransactionException("sh.t happens");
                    } catch (Exception e) {
                        System.out.println("thrown and catched");

                        e.printStackTrace();
                    }
                }
            } // END loop for the player from the server side list
        } else {
            System.out.println("Seems like somebody messed up with the values.");
        }
        return squadChanged;
    }

在抛出 TransactionException 时，我希望回滚机制起作用，但它没有起作用，并且实体被持久化..

下面是persistence.xml

<?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:jdbc="http://www.springframework.org/schema/jdbc"
    xmlns:jpa="http://www.springframework.org/schema/data/jpa"
    xsi:schemaLocation="http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-4.0.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd">

    <!-- CREATES DATA SOURCE -->
    <!-- <bean class="java.net.URI" id="dbUrl">
        <constructor-arg value="#{systemEnvironment['DATABASE_URL']}" />
    </bean> -->

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="url"
            value="#{ 'jdbc:postgresql://' + 'localhost' + ':' + '5432' + '/handball' }" />
        <property name="username" value="'#{ 'postgres' }" />
        <property name="password" value="#{ '........' }" />
    </bean>

    <bean
        class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
        id="emf">
        <!-- Entities location -->
        <property name="packagesToScan" value="af.handball.entity"></property>
        <property name="dataSource" ref="dataSource" />
        <property name="jpaProperties">
            <props>
                <prop key="hibernate.show_sql">false</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop>
                <prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop>
                <prop key="hibernate.connection.autocommit">false</prop>
            </props>
        </property>

         <property name="persistenceProvider">
            <bean class="org.hibernate.jpa.HibernatePersistenceProvider" />
        </property>  

    </bean>
</beans>

如能提供我可能出错的任何信息，我将不胜感激，谢谢!

Answer 1

不要在事务方法中捕获异常。事务功能由包装服务对象的代理实现。异常必须到达代理，以便代理知道它需要回滚。如果您在服务方法中捕获到异常，那么代理不知道该事务应该失败。

删除异常周围的 try-catch block 并抛出异常，您应该会看到事务被回滚。