java - hibernate + postgres java.lang.ClassNotFoundException : jdbc. driverClassName

Question

我正在将 hibernate 和 postgres 9.6 与 intellij idea 和 maven 一起使用。 这是我的 hibernate 类

@Configuration
@EnableTransactionManagement
@PropertySource({"classpath:psql_config.properties"})
public class HibernateConfig {
    @Autowired
    private Environment env;

    @Bean
    public LocalSessionFactoryBean sessionFactory(){
        LocalSessionFactoryBean sessionFactory  = new LocalSessionFactoryBean();
        sessionFactory.setDataSource(restDataSource());
        sessionFactory.setPackagesToScan(new String[] {"ru.amoup"});
        sessionFactory.setHibernateProperties(hibernateProperties());
        return sessionFactory;
    }

    @Bean
    public DataSource restDataSource(){
        BasicDataSource dataSource = new BasicDataSource();
        dataSource.setDriverClassName("jdbc.driverClassName");
        dataSource.setUrl("jdbc.url");
        dataSource.setUsername("jdbc.user");
        dataSource.setPassword("jdbc.pass");
        return dataSource;
    }

    @Bean
    @Autowired
    public HibernateTransactionManager transactionManager(SessionFactory sessionFactory){
        HibernateTransactionManager txManager = new HibernateTransactionManager();
        txManager.setSessionFactory(sessionFactory);
        return txManager;
    }

    Properties hibernateProperties(){
        return new Properties(){
            {
                setProperty("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
                setProperty("hibernate.dialect", env.getProperty("hibernate.dialect"));
                setProperty("hibernate.globally_quoted_identifiers", "true");
            }
        };
    }

    @Bean
    public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
        return new PersistenceExceptionTranslationPostProcessor();
    }
}

这是我的属性文件

# postgresql
jdbc.driverClassName = org.postgresql.Driver
jdbc.url = jdbc:postgresql://localhost:5432/integration
jdbc.user = myuser
jdbc.pass = mypass

# hibernate.X
hibernate.dialect = org.hibernate.dialect.PostgreSQLDialect
hibernate.show_sql=false
hibernate.hbm2ddl.auto = validate

在maven中我有依赖

<dependency>
  <groupId>org.postgresql</groupId>
  <artifactId>postgresql</artifactId>
  <version>42.1.4</version>
</dependency>

而postgresql-42.1.4.jar放在WEB-INF\lib中

当我尝试启动我的应用程序时，我明白了

 org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ru.amoup.configuration.HibernateConfig: Invocation of init method failed; nested exception is org.hibernate.exception.GenericJDBCException: Unable to open JDBC Connection for DDL execution
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:742)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
    at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:668)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:634)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:682)
    at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:553)
    at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:494)
    at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:171)
    at javax.servlet.GenericServlet.init(GenericServlet.java:158)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1183)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1099)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:779)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:133)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1457)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)
Caused by: org.hibernate.exception.GenericJDBCException: Unable to open JDBC Connection for DDL execution
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:47)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:97)
    at org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl.getIsolatedConnection(DdlTransactionIsolatorNonJtaImpl.java:69)
    at org.hibernate.tool.schema.internal.exec.ImprovedExtractionContextImpl.getJdbcConnection(ImprovedExtractionContextImpl.java:60)
    at org.hibernate.tool.schema.extract.internal.SequenceInformationExtractorLegacyImpl.extractMetadata(SequenceInformationExtractorLegacyImpl.java:40)
    at org.hibernate.tool.schema.extract.internal.DatabaseInformationImpl.initializeSequences(DatabaseInformationImpl.java:65)
    at org.hibernate.tool.schema.extract.internal.DatabaseInformationImpl.<init>(DatabaseInformationImpl.java:59)
    at org.hibernate.tool.schema.internal.Helper.buildDatabaseInformation(Helper.java:132)
    at org.hibernate.tool.schema.internal.AbstractSchemaValidator.doValidation(AbstractSchemaValidator.java:61)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:191)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:309)
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:452)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:710)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
    at org.springframework.orm.hibernate5.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:511)
    at org.springframework.orm.hibernate5.LocalSessionFactoryBean.afterPropertiesSet(LocalSessionFactoryBean.java:495)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624)
    ... 36 more
Caused by: org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'jdbc.driverClassName'
    at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1136)
    at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:880)
    at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180)
    at org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl.getIsolatedConnection(DdlTransactionIsolatorNonJtaImpl.java:43)
    ... 52 more
Caused by: java.lang.ClassNotFoundException: jdbc.driverClassName
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1285)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:264)
    at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1130)
    ... 56 more

我看到过用这种方式检查驱动程序的建议:

public static void main(String[] args) throws Exception {
      System.out.println(Class.forName("org.postgresql.Driver"));
}

但它工作得很好!我做错了什么？

Answer 1

当您设置数据源时，您实际上并没有引用属性，您只是向它提供包含属性键的字符串。

你必须做这样的事情:

//class level variable
@Value("${jdbc.driverClassName}")
private String driverClassName;

//....
dataSource.setDriverClassName(driverClassName);