如何在使用基於java的配置時指定hibernate實體關聯的映射類？ （如@OneToOne等）

Question

我想徹底退出基於xml的映射，並使用基於java的配置寫入相同。直到我有使用實體映射的要求時，它才工作得很好。有人可以幫助我如何通過基於java的配置來指定hibernate映射嗎？

以下是hibernate xml配置示例。

<?xml version="1.0" encoding="utf-8"?> 
<!DOCTYPE hibernate-configuration SYSTEM "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> 


<hibernate-configuration> 
<session-factory> 
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property> 
    <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> 
    <property name="hibernate.connection.username">myuser</property> 
    <property name="hibernate.connection.password">mypassword</property> 
    <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/websystique</property> 
    <property name="show_sql">true</property> 
    <property name="format_sql">false</property> 
    <mapping class="com.myapps.testapps.model.Student"/> 
    <mapping class="com.myapps.testapps.model.University"/> 
</session-factory> 
</hibernate-configuration> 

我想知道怎樣在我HibernateConfig.java

<mapping class="com.myapps.testapps.model.Student"/> 
    <mapping class="com.myapps.testapps.model.University"/> 

相應的Java基礎的配置（HibernateConfig.java）指定以下映射。我正在跳過我的屬性文件，這是所有提到的hibernate屬性的地方。

@Configuration 
@EnableTransactionManagement 
@ComponentScan({"com.myapps.testapps.config"}) 
@PropertySource(value = ("classpath:application.properties")) 


public class HibernateConfig { 

@Autowired 
private Environment environment; 

@Bean 
public LocalSessionFactoryBean sessionFactory(){ 
    System.out.println("-----------------------------sessionfactory--------------------------"); 
    LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean(); 
    sessionFactory.setDataSource(dataSource()); 
    sessionFactory.setPackagesToScan(new String[]{"com.myapps.testapps.model"}); 
    sessionFactory.setHibernateProperties(hibernateProperties()); 
    return sessionFactory; 
} 

@Bean 
public DataSource dataSource(){ 
    System.out.println("-----------------------------datasource--------------------------"); 
    DriverManagerDataSource dataSource = new DriverManagerDataSource(); 
    dataSource.setDriverClassName(environment.getRequiredProperty("jdbc.driverClassName")); 
    dataSource.setUrl(environment.getRequiredProperty("jdbc.url")); 
    dataSource.setUsername(environment.getRequiredProperty("jdbc.username")); 
    dataSource.setPassword(environment.getRequiredProperty("jdbc.password")); 
    return dataSource; 
} 


private Properties hibernateProperties(){ 
    System.out.println("-----------------------------properties--------------------------"); 
    Properties properties = new Properties(); 
    properties.put("hibernate.dialect", environment.getRequiredProperty("hibernate.dialect")); 
    properties.put("hibernate.show_sql", environment.getRequiredProperty("hibernate.show_sql")); 
    properties.put("hibernate.format_sql", environment.getRequiredProperty("hibernate.format_sql")); 
    return properties; 
} 

@Bean 
@Autowired 
public HibernateTransactionManager transactionManager(SessionFactory s){ 
    System.out.println("-----------------------------transaction manager--------------------------"); 
    HibernateTransactionManager txManager = new HibernateTransactionManager(); 
    txManager.setSessionFactory(s); 
    return txManager; 
} 

}

另外我已經使用JPA註釋如下

@Entity 
@Table(name = "UNIVERSITY") 
public class University { 

@Id 
@GeneratedValue 
@Column(name = "UNIVERSITY_ID") 
private long id; 

@Column(name = "NAME") 
private String name; 

@Column(name = "COUNTRY") 
private String country; 

------------------------ 

和

@Entity 
@Table(name = "STUDENT") 
public class Student { 

@Id 
@GeneratedValue 
@Column(name = "STUDENT_ID") 
private long id; 

@Column(name = "FIRST_NAME") 
private String firstName; 

@Column(name = "LAST_NAME") 
private String lastName; 

@Column(name = "SECTION") 
private String section; 

@ManyToOne(optional = false) 
@JoinColumn(name="UNIVERSITY_ID") 
private University university; 
---------------------- 

關聯getter和setter方法沿。

在一篇文章中我已閱讀，另一種方法是，指定被映射的類，讓Hibernate來找到映射文檔是：

Configuration cfg = new Configuration() 
.addClass(org.hibernate.auction.Item.class) 
.addClass(org.hibernate.auction.Bid.class); 

但我真的沒有對如何將它添加到一個線索我的HibernateConfig.java文件。如果我沒有錯，我認爲這必須使用sessionFactory來完成。有人可以幫助我嗎？

---

由於在回答中提到，setPackagesToScan（）是等效的，我收到以下錯誤，當我用實體與協會已經有setPackagesToScan()和@Entity註解我現有的代碼。

Invocation of init method failed; nested exception is org.hibernate.AnnotationException: @OneToOne or @ManyToOne on com.myapps.testapps.model.Student.university references an unknown entity: java.lang.String

Answer 1

在你的XML配置的<mapping>屬性相當於setPackagesToScan()方法查找由@Entity註解，然後映射完成由他人JPA的註解類。

我不認爲在你的例子中有什麼問題......或者發佈你得到的錯誤或什麼都不起作用。