在Spring Boot应用程序中使用AttributeConverter时，要注意在使用自动配置时可能会遇到该问题。解决方法是手动将AttributeConverter注册到JPA配置中。

代码示例：

首先创建一个AttributeConverter：

@Converter
public class BooleanToYNConverter implements AttributeConverter {

    @Override
    public String convertToDatabaseColumn(Boolean attribute) {
        return attribute ? "Y" : "N";
    }

    @Override
    public Boolean convertToEntityAttribute(String dbData) {
        return "Y".equals(dbData);
    }
}

然后在应用程序的JPA配置中手动注册该转换器：

@Configuration
@EnableJpaRepositories(basePackages = "com.example.repository")
@EnableTransactionManagement
public class JpaConfig {

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory(
            DataSource dataSource, JpaVendorAdapter jpaVendorAdapter) {
        LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
        em.setDataSource(dataSource);
        em.setPackagesToScan("com.example.entity");
        // Add the BooleanToYNConverter to the JpaVendorAdapter's list of converters
        HibernateJpaVendorAdapter hibernateJpaVendorAdapter = (HibernateJpaVendorAdapter) jpaVendorAdapter;
        hibernateJpaVendorAdapter.setJpaPropertyMap(getJpaProperties());
        hibernateJpaVendorAdapter.setDatabasePlatform("org.hibernate.dialect.MySQL5InnoDBDialect");
        hibernateJpaVendorAdapter.setShowSql(false);
        return em;
    }

    @Bean
    public JpaTransactionManager transactionManager(LocalContainerEntityManagerFactoryBean entityManagerFactory) {
        return new JpaTransactionManager(entityManagerFactory.getObject());
    }

    @Bean
    public JpaVendorAdapter jpaVendorAdapter() {
        HibernateJpaVendorAdapter hibernateJpaVendorAdapter = new HibernateJpaVendorAdapter();
        hibernateJpaVendorAdapter.setShowSql(false);
        hibernateJpaVendorAdapter.setGenerateDdl(false);
        hibernateJpaVendorAdapter.setDatabase(Database.MYSQL);
        return hibernateJpaVendorAdapter;
    }

    private Map getJpaProperties() {
        Map properties = new HashMap<>();
        List> converters = new ArrayList<>();
        // Add the BooleanToYNConverter to the list of converters
        converters.add(new BooleanToYNConverter());
        properties.put("hibernate.ejb.naming_strategy", ImprovedNamingStrategy.class.getName());
        properties.put("hibernate.connection.CharSet", "utf-8");
        properties.put("hibernate.connection.characterEncoding", "utf-8");
        properties.put("hibernate.connection.useUnicode", true);
        properties.put("hibernate.show_sql", true);
        properties.put("hibernate.format_sql", true);
        properties.put("hibernate.hbm2ddl.auto", "none");
        properties.put("hibernate.dialect", "org.hibernate.dialect.MySQL5InnoDBDialect");
        properties.put("hibernate.ejb.metamodel.generation", "disabled");
        properties.put("hibernate.jdbc.batch_size", 20);
        properties.put("hibernate.jdbc.fetch_size", 100);
        properties.put("hibernate.connection.release_mode", "after_transaction");
        properties.put("hibernate.ejb.entitymanager_factory_name", "default");
        properties.put("hibernate.connection.provider_class", "org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider");
        properties.put("hibernate.c3p0.min_size", 2);
        properties.put("hibernate.c3p0.initialPoolSize",