JPA 2.0 和 Spring 3.1 的"No Persistence provider for EntityManager named manager1"错误

Question

我现在正在使用Spring 3.1和JPA 2.0进行一个项目，收到一条日志消息错误，告诉我："没有名为manager1的EntityManager的持久性提供程序"。

这是我的persistence.xml:

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
<persistence-unit name="DemoSpringCore" transaction-type="RESOURCE_LOCAL">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <class>app.demo.model.Operation</class>
    <properties>
        <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3309/test"/>
        <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>
        <property name="hibernate.connection.username" value="root"/>
        <property name="hibernate.connection.password" value="root"/>
        <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
        <property name="hibernate.show_sql" value="true"/>
    </properties>
</persistence-unit>

这是我管理的enity"Operation.java"：包app.demo.model；

import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name="operation")
public class Operation implements Serializable{
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private int id;
@Column(name="a",length=9)
private int a;
@Column(name="b",length=9)
private int b;
@Column(name="c",length=10)
private int c;
public int getA() {
    return a;
}
public void setA(int a) {
    this.a = a;
}
public int getB() {
    return b;
}
public void setB(int b) {
    this.b = b;
}
public int getC() {
    return c;
}
public void setC(int c) {
    this.c = c;
}
public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}
}

这是我的java配置文件"AppConfiguration.java"，它是Spring3.1:中"ApplicationContext.xml"的替代文件

package app.demo.config;
import java.util.Properties;
import com.jolbox.bonecp.BoneCPDataSource;
import javax.annotation.Resource;
import javax.sql.DataSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.ImportResource;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import app.demo.dao.OperationDAO;
import app.demo.dao.OperationDAOImpl;
import app.demo.service.OperationServiceImpl;
import app.demo.service.OperationService;
import org.hibernate.ejb.HibernatePersistence;
@Configuration
@PropertySource("/META-INF/application.properties")
public class AppConfiguration {
private static final String PROPERTY_NAME_DATABASE_DRIVER = "db.driver";
private static final String PROPERTY_NAME_DATABASE_PASSWORD = "db.password";
private static final String PROPERTY_NAME_DATABASE_URL = "db.url";
private static final String PROPERTY_NAME_DATABASE_USERNAME = "db.username";
private static final String PROPERTY_NAME_HIBERNATE_DIALECT = "hibernate.dialect";
private static final String PROPERTY_NAME_HIBERNATE_FORMAT_SQL = "hibernate.format_sql";
private static final String PROPERTY_NAME_HIBERNATE_SHOW_SQL = "hibernate.show_sql";
private static final String PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN = "entitymanager.packages.to.scan";
// private static final String PROPERTY_NAME_HIBERNATE_NAMING_STRATEGY =
// "hibernate.ejb.naming_strategy";
@Resource
private Environment environment;
@Bean(name = "operationServiceBean")
public OperationService operationService() {
    return new OperationServiceImpl();
}
@Bean(name = "operationDAOBean")
public OperationDAO operationDAO() {
    return new OperationDAOImpl();
}
@Bean
public DataSource dataSource() {
    BoneCPDataSource dataSource = new BoneCPDataSource();
    dataSource.setDriverClass(environment
            .getRequiredProperty(PROPERTY_NAME_DATABASE_DRIVER));
    dataSource.setJdbcUrl(environment
            .getRequiredProperty(PROPERTY_NAME_DATABASE_URL));
    dataSource.setUsername(environment
            .getRequiredProperty(PROPERTY_NAME_DATABASE_USERNAME));
    dataSource.setPassword(environment
            .getRequiredProperty(PROPERTY_NAME_DATABASE_PASSWORD));
    return (DataSource) dataSource;
}
@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactoryBean()
        throws ClassNotFoundException {
    LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();
    entityManagerFactoryBean
            .setPersistenceProviderClass(HibernatePersistence.class);
    entityManagerFactoryBean.setDataSource(dataSource());
    Properties jpaProterties = new Properties();
    jpaProterties.put(PROPERTY_NAME_HIBERNATE_DIALECT, environment
            .getRequiredProperty(PROPERTY_NAME_HIBERNATE_DIALECT));
    jpaProterties.put(PROPERTY_NAME_HIBERNATE_FORMAT_SQL, environment
            .getRequiredProperty(PROPERTY_NAME_HIBERNATE_FORMAT_SQL));
    jpaProterties.put(PROPERTY_NAME_HIBERNATE_SHOW_SQL, environment
            .getRequiredProperty(PROPERTY_NAME_HIBERNATE_SHOW_SQL));
    jpaProterties
            .put(PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN,
                    environment
                            .getRequiredProperty(PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN));
    // jpaProterties.put(PROPERTY_NAME_HIBERNATE_NAMING_STRATEGY,
    // environment
    // .getRequiredProperty(PROPERTY_NAME_HIBERNATE_NAMING_STRATEGY));
    entityManagerFactoryBean.setJpaProperties(jpaProterties);
    return entityManagerFactoryBean;
}
}

最后是我的"application.properties"，在这里我放置了数据源连接属性：

db.driver=com.mysql.jdbc.Driver
db.url=jdbc:mysql://localhost:3309/test
db.username=root
db.password=root
hibernate.dialect=org.hibernate.dialect.MySQLDialect
hibernate.format_sql=true
hibernate.show_sql=true
entitymanager.packages.to.scan=app.demo.model

p.S：我使用了"applicaction.properties"one_answers"persistence.xml"这两种方法，每种方法都是单独使用的，并且在同时使用这两种方式之后，我希望它们能起作用，但什么都没发生！此外，我在"AppConfiguration.java"one_answers"persistence.xml"中都添加了provider属性，并验证了所有依赖项jar文件的存在！

提前感谢：）

Answer 1

您必须将包设置为直接在emf中扫描，还必须设置持久性单元名称：

entityManagerFactoryBean.setPackagesToScan(...);
entityManagerFactoryBean.setPersistenceUnitName(...);

在这之后，您甚至不再需要persistence.xml了。

此外，我建议（如果您无论如何都去掉了persistence.xml）使用正确的jpa属性作为基本属性：

javax.persistence.jdbc.driver
javax.persistence.jdbc.url
javax.persistence.jdbc.user
javax.persistence.jdbc.password