java - 重复导入 : Employee -> Employee org. hibernate.InvalidMappingException : Could not parse mapping document from resource Employee. hbm.xml

Question

我是 hibernate 新手当我尝试执行下面的代码时，我遇到了以下异常:

org.hibernate.InvalidMappingException: 无法从资源 Employee.hbm.xml 解析映射文档

这是我的代码:

配置:

    <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/hibernatetest 
    </property> 
    <property name="hibernate.connection.username"> 
    root 
    </property> 
    <property name="hibernate.connection.password"> 
    root 
    </property> 

    <!-- List of XML mapping files --> 
    <mapping resource="Employee.hbm.xml"/> 

    </session-factory> 
    </hibernate-configuration> 

来源:

    package com.practice.HBtest; 

public class Employee {

    private int id;
    private String firstName;
    private String lastName;
    private Integer salary;

    public Employee() {}

    public Employee(String fname, String lname, int salary) {
        this.firstName = fname;
        this.lastName = lname;
        this.salary = salary;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String first_name) {
        this.firstName = first_name;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String last_name) {
        this.lastName = last_name;
    }

    public int getSalary() {
        return salary;
    }

    public void setSalary(int salary) {
        this.salary = salary;
    }
}

映射:

<hibernate-mapping> 
<class name="Employee" table="EMPLOYEE"> 
<id name="id" type="int" column="id"> 
<generator class="native"/> 
</id> 

<property name="firstname" column="first_name" type="String"/> 
<property name="lastname" column="last_name" type="String"/> 
<property name="salary" column="salary" type="int"/>    
</class> 
</hibernate-mapping> 

源摘录:

import org.hibernate.HibernateException;
import org.hibernate.SessionFactory;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;

public class EmployeeRecordManager {

    private static SessionFactory sessionFactory;
    private static ServiceRegistry serviceRegistry;
    private Session session;

    public static void main(String[] args) {

        EmployeeRecordManager erm = new EmployeeRecordManager();

        try {
            Configuration cfg = new Configuration().addResource("Employee.hbm.xml");
            SessionFactory sessionFactory = cfg.configure().buildSessionFactory(serviceRegistry);

        } catch (Exception e) {
            System.out.println(e);
        }
        Integer empID1 = erm.addEmployee("Amruta", "Ali", 1000);
        Integer empID2 = erm.addEmployee("Ruchi", "Das", 5000);
        Integer empID3 = erm.addEmployee("Mitul", "Paul", 10000);

        System.out.println(erm);

    }

    public Integer addEmployee(String fname, String lname, int salary) {
        Session session = sessionFactory.openSession();
        Transaction tx = null;
        Integer empID = null;
        try {
            tx = session.beginTransaction();
            Employee employee = new Employee(fname, lname, salary);
            empID = (Integer) session.save(employee);
            tx.commit();
        } catch (HibernateException e) {
            if (tx != null)
                tx.rollback();
            e.printStackTrace();
        } finally {
            session.close();
        }
        return empID;
    }

}







   Nov 7, 2012 5:36:15 PM org.hibernate.annotations.common.Version <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {4.0.1.Final}
Nov 7, 2012 5:36:15 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {4.1.8.Final}
Nov 7, 2012 5:36:15 PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
Nov 7, 2012 5:36:15 PM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
Nov 7, 2012 5:36:15 PM org.hibernate.cfg.Configuration addResource
INFO: HHH000221: Reading mappings from resource: Employee.hbm.xml
Nov 7, 2012 5:36:15 PM org.hibernate.cfg.Configuration configure
INFO: HHH000043: Configuring from resource: /hibernate.cfg.xml
Nov 7, 2012 5:36:15 PM org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: HHH000040: Configuration resource: /hibernate.cfg.xml
Nov 7, 2012 5:36:15 PM org.hibernate.cfg.Configuration addResource
INFO: HHH000221: Reading mappings from resource: Employee.hbm.xml
Nov 7, 2012 5:36:15 PM org.hibernate.cfg.Configuration doConfigure
INFO: HHH000041: Configured SessionFactory: null
Nov 7, 2012 5:36:15 PM org.hibernate.cfg.Configuration$MappingsImpl addImport
INFO: HHH000071: Duplicate import: Employee -> Employee
org.hibernate.InvalidMappingException: Could not parse mapping document from resource Employee.hbm.xml
    at org.hibernate.cfg.Configuration$MetadataSourceQueue.processHbmXml(Configuration.java:3417)
    at org.hibernate.cfg.Configuration$MetadataSourceQueue.processHbmXmlQueue(Configuration.java:3406)
    at org.hibernate.cfg.Configuration$MetadataSourceQueue.processMetadata(Configuration.java:3394)
    at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1341)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1737)
    at com.practice.HBtest.EmployeeRecordManager.main(EmployeeRecordManager.java:24)
Caused by: org.hibernate.DuplicateMappingException: Duplicate class/entity mapping Employee
    at org.hibernate.cfg.Configuration$MappingsImpl.addClass(Configuration.java:2582)
    at org.hibernate.cfg.HbmBinder.bindRoot(HbmBinder.java:174)
    at org.hibernate.cfg.Configuration$MetadataSourceQueue.processHbmXml(Configuration.java:3414)
    ... 5 more
Exception in thread "main" java.lang.NullPointerException
    at com.practice.HBtest.EmployeeRecordManager.addEmployee(EmployeeRecordManager.java:39)
    at com.practice.HBtest.EmployeeRecordManager.main(EmployeeRecordManager.java:30)
org.hibernate.InvalidMappingException: Could not parse mapping document from resource Employee.hbm.xml
After Adding the code mentioned by you was getting below Exception:


  Nov 7, 2012 6:48:24 PM org.hibernate.annotations.common.Version <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {4.0.1.Final}
Nov 7, 2012 6:48:24 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {4.1.8.Final}
Nov 7, 2012 6:48:24 PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
Nov 7, 2012 6:48:24 PM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
Nov 7, 2012 6:48:24 PM org.hibernate.cfg.Configuration configure
INFO: HHH000043: Configuring from resource: hibernate.cfg.xml
Nov 7, 2012 6:48:24 PM org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: HHH000040: Configuration resource: hibernate.cfg.xml
Nov 7, 2012 6:48:24 PM org.hibernate.cfg.Configuration addResource
INFO: HHH000221: Reading mappings from resource: Employee.hbm.xml
Nov 7, 2012 6:48:24 PM org.hibernate.cfg.Configuration doConfigure
INFO: HHH000041: Configured SessionFactory: null
Nov 7, 2012 6:48:24 PM org.hibernate.cfg.Configuration configure
INFO: HHH000043: Configuring from resource: /hibernate.cfg.xml
Nov 7, 2012 6:48:24 PM org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: HHH000040: Configuration resource: /hibernate.cfg.xml
Nov 7, 2012 6:48:24 PM org.hibernate.cfg.Configuration addResource
INFO: HHH000221: Reading mappings from resource: Employee.hbm.xml
Nov 7, 2012 6:48:24 PM org.hibernate.cfg.Configuration doConfigure
INFO: HHH000041: Configured SessionFactory: null
Nov 7, 2012 6:48:24 PM org.hibernate.cfg.Configuration$MappingsImpl addImport
INFO: HHH000071: Duplicate import: Employee -> Employee
org.hibernate.InvalidMappingException: Could not parse mapping document from resource Employee.hbm.xml
    at org.hibernate.cfg.Configuration$MetadataSourceQueue.processHbmXml(Configuration.java:3417)
    at org.hibernate.cfg.Configuration$MetadataSourceQueue.processHbmXmlQueue(Configuration.java:3406)
    at org.hibernate.cfg.Configuration$MetadataSourceQueue.processMetadata(Configuration.java:3394)
    at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1341)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1737)
    at com.practice.HBtest.EmployeeRecordManager.main(EmployeeRecordManager.java:24)
Caused by: org.hibernate.DuplicateMappingException: Duplicate class/entity mapping Employee
    at org.hibernate.cfg.Configuration$MappingsImpl.addClass(Configuration.java:2582)
    at org.hibernate.cfg.HbmBinder.bindRoot(HbmBinder.java:174)
    at org.hibernate.cfg.Configuration$MetadataSourceQueue.processHbmXml(Configuration.java:3414)
    ... 5 more
Exception in thread "main" java.lang.NullPointerException
    at com.practice.HBtest.EmployeeRecordManager.addEmployee(EmployeeRecordManager.java:39)
    at com.practice.HBtest.EmployeeRecordManager.main(EmployeeRecordManager.java:30)
org.hibernate.InvalidMappingException: Could not parse mapping document from resource Employee.hbm.xml

Answer 1

您的 hbm.xml 属性名称之间存在大小写差异:

<property name="firstname" column="first_name" type="String"/> 
<property name="lastname" column="last_name" type="String"/> 
<property name="salary" column="salary" type="int"/> 

以及您类(class)中的实际成员字段:

private String first**N**ame; 
private String last**N**ame; 
private Integer salary; 

更重要的是，你类的 getter 和 setter 也有驼峰式封装，而 hibernate 会寻找getFirstname(), setFirstname(), ...