Question

我是使用Maven，Hibernate和h2数据库的新手，我试图创建嵌入式h2数据库，但是当我运行应用程序时，出现错误，我在做什么错？为了澄清起见，我仍然没有创建h2数据库，如果t，应用程序必须能够创建h2数据库。这里是代码。

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.luis</groupId>
  <artifactId>PruebaHiber</artifactId>
  <version>1.0.0-SNAPSHOT</version>

  <dependencies>
    <!-- https://mvnrepository.com/artifact/org.hibernate.orm/hibernate-core -->
    <dependency>
      <groupId>org.hibernate.orm</groupId>
      <artifactId>hibernate-core</artifactId>
      <version>6.0.0.Alpha2</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.h2database/h2 -->
    <dependency>
      <groupId>com.h2database</groupId>
      <artifactId>h2</artifactId>
      <version>1.4.199</version>
      <scope>test</scope>
    </dependency>
  </dependencies>

  <properties>
    <maven.compiler.target>1.8</maven.compiler.target>
    <maven.compiler.source>1.8</maven.compiler.source>
  </properties>
</project>

persistence.xml

<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence

http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"

  version="2.1">

  <persistence-unit name="persistenceUnit">
    <properties>
      <!-- Configuring JDBC properties -->
      <property name="javax.persistence.jdbc.url" value="jdbc:h2:file:./test"/>
      <property name="javax.persistence.jdbc.user" value="sa" />
      <property name="javax.persistence.jdbc.password" value="" />
      <property name="javax.persistence.jdbc.driver" value="org.h2.Driver" />

      <!-- Hibernate properties -->
      <property name="hibernate.show_sql" value="true" />
      <property name="hibernate.format_sql" value="true" />
      <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect" />
      <property name="hibernate.hbm2ddl.auto" value="create" />
    </properties>
  </persistence-unit>
</persistence>

Principal.java

package com.luis.pruebahiber;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

public class Principal {

	public Principal() {
		// TODO Auto-generated constructor stub
	}
	
	public static void main(String []args) {
		EntityManagerFactory emf = Persistence.createEntityManagerFactory("persistenceUnit");
		EntityManager em = emf.createEntityManager();
		em.close();
		emf.close();
	}
}

这是错误

Jun 10, 2019 3:29:00 PM org.hibernate.jpa.internal.util.LogHelper logPersistenceUnitInformation
INFO: HHH000204: Processing PersistenceUnitInfo [
	name: persistenceUnit
	...]
Jun 10, 2019 3:29:01 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {6.0.0.Alpha2}
Jun 10, 2019 3:29:01 PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
Jun 10, 2019 3:29:01 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.1.0.Final}
Jun 10, 2019 3:29:02 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
Exception in thread "main" org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:275)
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237)
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
	at org.hibernate.boot.model.relational.Database.<init>(Database.java:41)
	at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.getDatabase(InFlightMetadataCollectorImpl.java:216)
	at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.<init>(InFlightMetadataCollectorImpl.java:187)
	at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:123)
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:903)
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:936)
	at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:56)
	at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:79)
	at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54)
	at com.luis.pruebahiber.Principal.main(Principal.java:14)
Caused by: org.hibernate.boot.registry.classloading.spi.ClassLoadingException: Unable to load class [org.h2.Driver]
	at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.classForName(ClassLoaderServiceImpl.java:136)
	at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.loadDriverIfPossible(DriverManagerConnectionProviderImpl.java:149)
	at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildCreator(DriverManagerConnectionProviderImpl.java:105)
	at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildPool(DriverManagerConnectionProviderImpl.java:89)
	at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:73)
	at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:100)
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:246)
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.buildJdbcConnectionAccess(JdbcEnvironmentInitiator.java:178)
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:102)
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
	at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:94)
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:263)
	... 12 more
Caused by: java.lang.ClassNotFoundException: Could not load requested class : org.h2.Driver
	at org.hibernate.boot.registry.classloading.internal.AggregatedClassLoader.findClass(AggregatedClassLoader.java:210)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:563)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:496)
	at java.base/java.lang.Class.forName0(Native Method)
	at java.base/java.lang.Class.forName(Class.java:375)
	at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.classForName(ClassLoaderServiceImpl.java:133)
	... 24 more

Answer 1

您在pom.xml的测试范围中具有h2依赖项，因此它在运行时不可用。仅适用于您的测试。

使用默认范围（编译）-只需删除范围标签即可。

为什么在H2数据库中使用Hibernate会出现错误？

1 个答案: