我有2个POJO的员工和地址以及两个表员工和地址。我首先尝试将地址行添加到数据库中，然后添加一个员工记录，其中包含先前添加的地址记录的引用。只有在配置文件中有一个映射资源时，我才能添加地址记录。
我的主要文件：`package many2one;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
public class ManageEmployee {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
Session session = null;
try
{
Configuration configuration = new Configuration();
configuration.configure("many2one/hibernate.cfg.xml");
ServiceRegistry sr = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
SessionFactory sf = configuration.buildSessionFactory(sr);
session = sf.openSession();
session.beginTransaction();
System.out.println("Populating the Database.");
Address1 address = new Address1("Mogappair","Chennai","Tamilnadu","600107");
session.save(address);
session.getTransaction().commit();
System.out.println("Done");
}catch(HibernateException he){
System.out.println("Exception Thrown " + he);
}finally{
session.flush();
session.close();
}
}
}
我的员工POJO：
package many2one;
import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
@Entity(name="employee")
public class Employee1 implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
public Long id;
public String firstName;
public String lastName;
public int salary;
public Address1 address;
public Employee1(){}
public Employee1(String f_name,String l_name,int sal,Address1 add){
this.firstName = f_name;
this.lastName = l_name;
this.salary = sal;
this.address = add;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getFirstName(){
return firstName;
}
public void setFirstName(String f_name){
this.firstName = f_name;
}
public String getLastName(){
return lastName;
}
public void setLastName(String l_name){
this.lastName = l_name;
}
public Address1 getAddress(){
return address;
}
public void setAddress(Address1 address){
this.address = address;
}
}
我的地址文件
package many2one;
import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
@Entity(name="address")
public class Address1 implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
public Long id;
public String streetName;
public String cityName;
public String stateName;
public String zipcode;
public Address1(){}
public Address1(String s_name,String c_name,String st_name,String zipcode){
this.streetName = s_name;
this.cityName = c_name;
this.stateName = st_name;
this.zipcode = zipcode;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getStreetName() {
return streetName;
}
public void setStreetName(String s_name) {
this.streetName = s_name;
}
public String getCityName() {
return cityName;
}
public void setCityName(String c_name) {
this.cityName = c_name;
}
public String getStateName() {
return stateName;
}
public void setStateName(String state_name) {
this.stateName = state_name;
}
public String getZipcode() {
return zipcode;
}
public void setZipcode(String zipcode) {
this.zipcode = zipcode;
}
}
配置文件：
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"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.url">jdbc:mysql://localhost:3306/hibernate?zeroDateTimeBehavior=convertToNull</property>
<property name="hibernate.connection.username">root</property>
<!--<mapping resource="many2one/Mapping.hbm.xml"/>-->
<mapping resource="many2one/Address1.hbm.xml"/>
</session-factory>
</hibernate-configuration>
映射文件：
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="many2one.Employee1" table="employee">
<meta attribute="class-description">
This contains the Employee Details
</meta>
<id name="id" column="id" type="long">
<generator class="native"></generator>
</id>
<property name="firstName" column="first_name" type="string"></property>
<property name="lastName" column="last_name" type="string"></property>
<property name="salary" column="salary" type="string"></property>
<many-to-one name="address" column="address" class="many2one.Address1" not-null="true"/>
</class>
<class name="many2one.Address1" table="address">
<meta attribute="class-description">
This contains the Address Details
</meta>
<id name="id" column="id" type="long">
<generator class="native"></generator>
</id>
<property name="streetName" column="street_name" type="string"></property>
<property name="cityName" column="city_name" type="string"></property>
<property name="stateName" column="state_name" type="string"></property>
<property name="zipcode" column="zipcode" type="string"></property>
</class>
</hibernate-mapping>
我的任务是在数据库中添加地址记录，然后使用带有地址引用的employee构造函数添加员工记录。当employee表的映射资源被注释掉时，我能够添加地址记录，但如果我尝试两者，那么我会收到错误。无法获得构造函数错误。
堆栈跟踪：`调试：
Feb 26, 2015 11:19:10 AM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {4.0.4.Final}
Feb 26, 2015 11:19:11 AM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {4.3.1.Final}
Feb 26, 2015 11:19:11 AM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
Feb 26, 2015 11:19:11 AM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
Feb 26, 2015 11:19:12 AM org.hibernate.cfg.Configuration configure
INFO: HHH000043: Configuring from resource: many2one/hibernate.cfg.xml
Feb 26, 2015 11:19:12 AM org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: HHH000040: Configuration resource: many2one/hibernate.cfg.xml
Feb 26, 2015 11:19:12 AM org.hibernate.cfg.Configuration addResource
INFO: HHH000221: Reading mappings from resource: many2one/Mapping.hbm.xml
Feb 26, 2015 11:19:13 AM org.hibernate.cfg.Configuration doConfigure
INFO: HHH000041: Configured SessionFactory: null
Feb 26, 2015 11:19:15 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH000402: Using Hibernate built-in connection pool (not for production use!)
Feb 26, 2015 11:19:16 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000401: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/hibernate?zeroDateTimeBehavior=convertToNull]
Feb 26, 2015 11:19:16 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000046: Connection properties: {user=root}
Feb 26, 2015 11:19:16 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000006: Autocommit mode: false
Feb 26, 2015 11:19:16 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
INFO: HHH000115: Hibernate connection pool size: 20 (min=1)
Feb 26, 2015 11:19:17 AM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
Feb 26, 2015 11:19:18 AM org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService
INFO: HHH000399: Using default transaction strategy (direct JDBC transactions)
Feb 26, 2015 11:19:18 AM org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory <init>
INFO: HHH000397: Using ASTQueryTranslatorFactory
Feb 26, 2015 11:19:19 AM org.hibernate.validator.internal.util.Version <clinit>
INFO: HV000001: Hibernate Validator 5.0.0.Final
Exception Thrown org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister
`
`
答案 0 :(得分：0)
在配置文件中添加多个映射文件为
<mapping resource="path/Address.hbm.xml"/>
<mapping resource="path/Employee.hbm.xml"/>