无法确定“oracle”的方言

Question

我正在使用 Spring boot(2.3.5)、Oracle19c DB 和 Hibernate(5.4)。

我尝试建立多数据源连接，但我不断收到方言错误Couldn't determine Dialect for "oracle"。

在类路径资源 [org/springframework/boot/autoconfigure/data/jdbc/JdbcRepositoriesAutoConfiguration$SpringBootJdbcConfiguration.class] 中创建名称为“jdbcDialect”的 bean 时出错：通过工厂方法实例化 bean 失败；嵌套异常是 org.springframework.beans.BeanInstantiationException：无法实例化 [org.springframework.data.relational.core.dialect.Dialect]：工厂方法“jdbcDialect”抛出异常；嵌套异常是 org.springframework.data.jdbc.repository.config.DialectResolver$NoDialectException：无法确定 org.springframework.jdbc.core.JdbcTemplate@2ba9ed19 的方言。请提供方言。

我基本上是跟着this tutorial配置多个数据源的。

application.properties:

spring.datasource-primary.username=oracleprimary
spring.datasource-primary.password=oracleprimary
spring.datasource-primary.url=jdbc:oracle:thin:@//localhost:1521/orcl

spring.datasource-secondary.driver-class-name=oracle.jdbc.OracleDriver
spring.datasource-secondary.username=oraclesecondary
spring.datasource-secondary.password=oraclesecondary
spring.datasource-secondary.url=jdbc:oracle:thin:@//localhost:1521/orcl

主要配置：

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "primaryEntityManagerFactory",
        transactionManagerRef = "primaryTransactionManager",
        basePackages = {"com.foo.primary.repository"})
public class PrimaryDataSourceConfiguration {

    @Primary
    @Bean(name = "primaryDataSourceProperties")
    @ConfigurationProperties("spring.datasource-primary")
    public DataSourceProperties primaryDataSourceProperties() {
        return new DataSourceProperties();
    }

    @Primary
    @Bean(name = "primaryDataSource")
    @ConfigurationProperties("spring.datasource-primary.configuration")
    public DataSource primaryDataSource(@Qualifier("primaryDataSourceProperties") DataSourceProperties primaryDataSourceProperties) {
        return primaryDataSourceProperties.initializeDataSourceBuilder().type(HikariDataSource.class).build();
    }

    @Primary
    @Bean(name = "primaryEntityManagerFactory")
    public LocalContainerEntityManagerFactoryBean primaryEntityManagerFactory(
            EntityManagerFactoryBuilder primaryEntityManagerFactoryBuilder, @Qualifier("primaryDataSource") DataSource primaryDataSource) {

        Map<String, String> primaryJpaProperties = new HashMap<>();
        primaryJpaProperties.put("hibernate.dialect", "org.hibernate.dialect.Oracle12cDialect");

        return primaryEntityManagerFactoryBuilder
                .dataSource(primaryDataSource)
                .packages("com.foo.primary.model")
                .persistenceUnit("primaryDataSource")
                .properties(primaryJpaProperties)
                .build();
    }

    @Primary
    @Bean(name = "primaryTransactionManager")
    public PlatformTransactionManager primaryTransactionManager(
            @Qualifier("primaryEntityManagerFactory") EntityManagerFactory primaryEntityManagerFactory) {

        return new JpaTransactionManager(primaryEntityManagerFactory);
    }

第二次配置：

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "secondaryEntityManagerFactory",
        transactionManagerRef = "secondaryTransactionManager",
        basePackages = {"com.foo.secondary.repository"})
public class SecondaryDataSourceConfiguration {

    @Bean(name = "secondaryDataSourceProperties")
    @ConfigurationProperties("spring.datasource-secondary")
    public DataSourceProperties secondaryDataSourceProperties() {
        return new DataSourceProperties();
    }

    @Bean(name = "secondaryDataSource")
    @ConfigurationProperties("spring.datasource-secondary.configuration")
    public DataSource secondaryDataSource(@Qualifier("secondaryDataSourceProperties") DataSourceProperties secondaryDataSourceProperties) {
        return secondaryDataSourceProperties.initializeDataSourceBuilder().type(HikariDataSource.class).build();
    }

    @Bean(name = "secondaryEntityManagerFactory")
    public LocalContainerEntityManagerFactoryBean secondaryEntityManagerFactory(
            EntityManagerFactoryBuilder secondaryEntityManagerFactoryBuilder, @Qualifier("secondaryDataSource") DataSource secondaryDataSource) {

        Map<String, String> secondaryJpaProperties = new HashMap<>();
        secondaryJpaProperties.put("hibernate.dialect", "org.hibernate.dialect.Oracle12cDialect");

        return secondaryEntityManagerFactoryBuilder
                .dataSource(secondaryDataSource)
                .packages("com.foo.secondary.model")
                .persistenceUnit("secondaryDataSource")
                .properties(secondaryJpaProperties)
                .build();
    }

    @Bean(name = "secondaryTransactionManager")
    public PlatformTransactionManager secondaryTransactionManager(
            @Qualifier("secondaryEntityManagerFactory") EntityManagerFactory secondaryEntityManagerFactory) {

        return new JpaTransactionManager(secondaryEntityManagerFactory);
    }
}

我也尝试了org.hibernate.dialect.Oracle10gDialect，并在application.properties 中设置了spring.jpa.database-platform=org.hibernate.dialect.Oracle12cDialect，但没有任何改变。

如何正确配置 oracle 的方言？

Answer 1

Spring Data JDBC does not support oracle dialect。您需要定义实现JdbcDialectProvider 的方言。

public final class OracleDialect implements DialectResolver.JdbcDialectProvider {

    private static Dialect getDialect(Connection connection) throws SQLException {
        DatabaseMetaData metaData = connection.getMetaData();
        String name = metaData.getDatabaseProductName().toLowerCase(Locale.ROOT);

        if (name.contains("oracle")) {
            return AnsiDialect.INSTANCE;
        }

        return null;
    }

    @Override
    public Optional<Dialect> getDialect(JdbcOperations operations) {
        return Optional.ofNullable(operations.execute((ConnectionCallback<Dialect>) OracleDialect::getDialect));
    }
}

在您的build.gradle 或pom.xml 中添加spring-boot-starter-data-jdbc 依赖项。

然后，as mentioned in the blog，在resources/META-INF中创建spring.factories文件，并粘贴以下命令：

org.springframework.data.jdbc.repository.config.DialectResolver$JdbcDialectProvider=<your-package>.OracleDialect

另外，由于您使用的两个数据库是相同的（OracleDB），您不需要为实体管理器设置.properties()。正如@SternK 提到的，您只能在application.properties 中包含spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.Oracle12cDialect。