在使用时出现了LazyInitializationException无法初始化代理-没有会话的问题。

我在使用Hibernate时遇到了著名的LazyInitializationException问题。我已经看了很多关于这个问题的问题，但仍然无法解决我的问题。\n我有一个多对多的关系，如下所示：\nTeen.java\n

public class Teen implements Serializable {
    @ManyToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    @JoinTable(name = "TEEN_FOLLOWER",
            joinColumns = @JoinColumn(name = "teenEmail"),
            inverseJoinColumns = @JoinColumn(name = "followerEmail"))
    private List followerList;
}

\nFollower.java\n

public class Follower implements Serializable {
    @ManyToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    @JoinTable(name = "TEEN_FOLLOWER",
            joinColumns = @JoinColumn(name = "followerEmail"),
            inverseJoinColumns = @JoinColumn(name = "teenEmail"))
    private List teenList;
}

\n一个Teen有n个Follower，一个Follower可以关注n个Teen。\n我的数据库中已经有一些记录，我正在获取所有的Teen。\n

List teens = (List) teenDao.findAll();
for (Teen item : teens) {
    System.out.println("teen " + item.getEmail());
    List followers = item.getFollowerList();
    for (Follower follower : followers) {
        System.out.println("follower " + follower.getEmail());
    }
}

\n当我尝试从getFollowerList()方法获取的followers列表中读取时，我在上面的代码中遇到了异常。\n

org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.capstone.server.model.Teen.followerList, could not initialize proxy - no Session
    org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:572)
    org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:212)
    org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:551)
    org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:140)
    org.hibernate.collection.internal.PersistentBag.iterator(PersistentBag.java:294)
    com.capstone.server.controller.TeenController.visualizar(TeenController.java:38)
    ...

\n真的不知道该怎么办了。我已经尝试在引发错误的方法中添加了@Transactional注解，并且是有效的。然而，当我将Teen对象发送到我的Android应用程序时，转换对象为json时我遇到了相同的异常。\n我的配置文件如下：\nservlet-context.xml\n

\nPersistenceJPAConfig.java\n

@Configuration
@EnableTransactionManagement
@PropertySource("classpath:application.properties")
public class PersistenceJPAConfig {
    @Resource
    private Environment env;
    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
        em.setDataSource(dataSource());
        em.setPackagesToScan(new String[] {
                Constants.PACKAGE_NAME
        });
        JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        em.setJpaVendorAdapter(vendorAdapter);
        em.setJpaProperties(additionalProperties());
        return em;
    }
    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        // Connection data
        dataSource.setDriverClassName(env.getRequiredProperty("db.driver"));
        dataSource.setUrl(env.getRequiredProperty("db.url"));
        dataSource.setUsername(env.getRequiredProperty("db.username"));
        dataSource.setPassword(env.getRequiredProperty("db.password"));
        return dataSource;
    }
    @Bean
    public PlatformTransactionManager transactionManager(EntityManagerFactory emf) {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(emf);
        return transactionManager;
    }
    @Bean
    public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
        return new PersistenceExceptionTranslationPostProcessor();
    }
    Properties additionalProperties() {
        Properties properties = new Properties();
        // Hibernate properties
        properties.setProperty("hibernate.dialect", env.getRequiredProperty("hibernate.dialect"));
        properties.setProperty("hibernate.show_sql", env.getRequiredProperty("hibernate.show_sql"));
        properties.setProperty("hibernate.format_sql",
                env.getRequiredProperty("hibernate.format_sql"));
        // Updates the database and generate tables, if needed
        properties.setProperty("hibernate.hbm2ddl.auto",
                env.getRequiredProperty("hibernate.hbm2ddl.auto"));
        // Initializes database with admin entry in User table
        properties.setProperty("hibernate.hbm2ddl.import_files",
                env.getRequiredProperty("hibernate.hbm2ddl.import_files"));
        properties.setProperty("hibernate.hbm2ddl.import_files_sql_extractor",
                env.getRequiredProperty("hibernate.hbm2ddl.import_files_sql_extractor"));
        return properties;
    }
}