我看到＆＃34;类似＆＃34;许多网站的问题，但无法解决我的问题。我正在使用以下软件/配置。
1.Eclipse版本：Neon.3发布（4.6.3）
2.Hibernate Tools 5.1.3.v20170210-1113
3.MySql 5.6.36
当我运行持久性＆＃34; ManageEmployee＆＃34;时，我收到以下错误类。
May 07, 2017 1:53:26 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.2.10.Final}
May 07, 2017 1:53:26 PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000205: Loaded properties from resource hibernate.properties: {hibernate.connection.driver_class=org.h2.Driver, hibernate.service.allow_crawling=false, hibernate.max_fetch_depth=5, hibernate.dialect=org.hibernate.dialect.H2Dialect, hibernate.format_sql=true, hibernate.generate_statistics=true, hibernate.connection.username=sa, hibernate.connection.url=jdbc:h2:mem:db1;DB_CLOSE_DELAY=-1;LOCK_TIMEOUT=10000, hibernate.bytecode.use_reflection_optimizer=false, hibernate.connection.password=****, hibernate.connection.pool_size=5}
May 07, 2017 1:53:27 PM org.hibernate.spatial.integration.SpatialService <init>
INFO: HHH80000001: hibernate-spatial integration enabled : true
May 07, 2017 1:53:27 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
May 07, 2017 1:53:29 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
May 07, 2017 1:53:30 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/testdb]
May 07, 2017 1:53:30 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: Connection properties: {user=root, password=****}
May 07, 2017 1:53:30 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit mode: false
May 07, 2017 1:53:30 PM org.hibernate.engine.jdbc.connections.internal.PooledConnections <init>
INFO: HHH000115: Hibernate connection pool size: 5 (min=1)
May 07, 2017 1:53:30 PM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
May 07, 2017 1:53:31 PM org.hibernate.envers.boot.internal.EnversServiceImpl configure
INFO: Envers integration enabled? : true
Failed to create sessionFactory object.org.hibernate.boot.registry.classloading.spi.ClassLoadingException: Unable to load class [Employee]
Exception in thread "main" java.lang.ExceptionInInitializerError
at hibernatePackage.ManageEmployee.main(ManageEmployee.java:20)
Caused by: org.hibernate.boot.registry.classloading.spi.ClassLoadingException: Unable to load class [Employee]
at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.classForName(ClassLoaderServiceImpl.java:348)
at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.<init>(AnnotationMetadataSourceProcessorImpl.java:104)
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess$1.<init>(MetadataBuildingProcess.java:147)
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:141)
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83)
at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:418)
at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
at hibernatePackage.ManageEmployee.main(ManageEmployee.java:17)
Caused by: java.lang.ClassNotFoundException: Could not load requested class : Employee
at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl$AggregatedClassLoader.findClass(ClassLoaderServiceImpl.java:336)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.classForName(ClassLoaderServiceImpl.java:345)
... 9 more
Package explorer hierarchy snapshot
Hibernate映射文件：Employee.hbm.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="hibernatePackage.Employee" table="EMPLOYEE">
<meta attribute="class-description">
This class contains the employee detail.
</meta>
<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>
Hibernate配置文件：hibernate.cfg.xml
<?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 name="">
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/testdb</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<mapping class="Employee" package="hibernatePackage" resource="resource"/>
<mapping resource="hibernatePackage/Employee.hbm.xml"/>
<mapping class="hibernatePackage.Employee"/>
</session-factory>
</hibernate-configuration>
POJO类：Employee.java
package hibernatePackage;
public class Employee {
private int id;
private String firstName;
private String lastName;
private int 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;
}
}
要持久化对象的类：ManageEmployee.java
package hibernatePackage;
import java.util.List;
import java.util.Date;
import java.util.Iterator;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class ManageEmployee {
private static SessionFactory factory;
public static void main(String[] args) {
try{
factory = new Configuration().configure().buildSessionFactory();
}catch (Throwable ex) {
System.err.println("Failed to create sessionFactory object." + ex);
throw new ExceptionInInitializerError(ex);
}
ManageEmployee ME = new ManageEmployee();
/* Add few employee records in database */
Integer empID1 = ME.addEmployee("Zara", "Ali", 1000);
Integer empID2 = ME.addEmployee("Daisy", "Das", 5000);
Integer empID3 = ME.addEmployee("John", "Paul", 10000);
/* List down all the employees */
ME.listEmployees();
/* Update employee's records */
ME.updateEmployee(empID1, 5000);
/* Delete an employee from the database */
ME.deleteEmployee(empID2);
/* List down new list of the employees */
ME.listEmployees();
}
/* Method to CREATE an employee in the database */
public Integer addEmployee(String fname, String lname, int salary){
Session session = factory.openSession();
Transaction tx = null;
Integer employeeID = null;
try{
tx = session.beginTransaction();
Employee employee = new Employee(fname, lname, salary);
employeeID = (Integer) session.save(employee);
tx.commit();
}catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
}finally {
session.close();
}
return employeeID;
}
/* Method to READ all the employees */
public void listEmployees( ){
Session session = factory.openSession();
Transaction tx = null;
try{
tx = session.beginTransaction();
List employees = session.createQuery("FROM Employee").list();
for (Iterator iterator =
employees.iterator(); iterator.hasNext();){
Employee employee = (Employee) iterator.next();
System.out.print("First Name: " + employee.getFirstName());
System.out.print(" Last Name: " + employee.getLastName());
System.out.println(" Salary: " + employee.getSalary());
}
tx.commit();
}catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
}finally {
session.close();
}
}
/* Method to UPDATE salary for an employee */
public void updateEmployee(Integer EmployeeID, int salary ){
Session session = factory.openSession();
Transaction tx = null;
try{
tx = session.beginTransaction();
Employee employee =
(Employee)session.get(Employee.class, EmployeeID);
employee.setSalary( salary );
session.update(employee);
tx.commit();
}catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
}finally {
session.close();
}
}
/* Method to DELETE an employee from the records */
public void deleteEmployee(Integer EmployeeID){
Session session = factory.openSession();
Transaction tx = null;
try{
tx = session.beginTransaction();
Employee employee =
(Employee)session.get(Employee.class, EmployeeID);
session.delete(employee);
tx.commit();
}catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
}finally {
session.close();
}
}
}
答案 0 :(得分：1)
源代码怎么样？
我已经发布了你的stackTrace片段：
<?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.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hb_employee_tracker?useSSL=false</property>
<property name="hibernate.connection.username">hbemployee</property>
<property name="hibernate.connection.password">hbemployee</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="connection.pool_size">1</property>
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="show_sql">true</property>
<property name="current_session_context_class">thread</property>
</session-factory>
</hibernate-configuration>
也许它出了什么问题？
- UPD --- 我改变了一些东西，并没有触及其他方法，比如添加，列出ets。 另外我不知道如何制作好的xml映射，所以如果你也不知道，请使用像我这样的java注释。
所以，我的下面的事情：
<强> hibernate.cfg.xml中
package hibernatepackage.entity;
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 = "employee")
public class Employee {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private int id;
@Column(name="first_name")
private String firstName;
@Column(name="last_name")
private String lastName;
@Column(name="salary")
private int 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;
}
}
<强> Employee.java
package hibernatepackage.persistance;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import hibernatepackage.entity.Employee;
public class ManageEmployee {
private static SessionFactory factory;
public static void main(String[] args) {
factory = new Configuration()
.configure("hibernate.cfg.xml")
.addAnnotatedClass(Employee.class)
.buildSessionFactory();
Session session = factory.getCurrentSession();
Employee emp0 = new Employee("John", "Doe", 1000);
Employee emp1 = new Employee("Richard", "Roe", 2000);
Employee emp2 = new Employee("Joe", "Bloggs", 3000);
Employee emp3= new Employee("Another", "Everyman", 4000);
try {
session.beginTransaction();
session.save(emp0);
session.save(emp1);
session.save(emp2);
session.save(emp3);
session.getTransaction().commit();
} finally {
factory.close();
}
}
}
这是你的persistense课没有和另一个东西： ManageEmployee.java
/myfeed.php?start=2013-12-01&end=2014-01-12&_=1386054751381
上面的代码为数据库添加了4个新实体。我在MySQL localhost DB上测试它。
答案 1 :(得分：0)
为什么要在hibernate配置文件中映射<?php
$title = 'My awesome title';
/** Here your php code to get the content and assign variable to all nodes **/
$title_old = $title; /** Get the info your xml script or cached XML data **/
$title_new = 'My awesome title'; /** Use YOUR new value! - requestt the content again after someone clicked the save button or use a crontab to get info on changes every x minutes, hours or days **/
if($title_new == $title_old){
$title_changed = 'No changes detected to the title node';
echo $title_changed . ': The title is "' . $title . '"';
}else{
$title_changed = 'The title node has been changed';
echo $title_changed . ': The new title is "' . $title . '"';
}
?>
文件和hbm类？
<强>问题：
您只需要在Pojo中映射Employee.hbm文件，Hibernate.cfg.xml类已经映射到Employee.java文件中，这是导致此问题的原因异常。
如果您将其映射到Employee.hbm，则hibernate会查找此类中的Hibernate.cfg.xml配置，从而触发Annotations。
<强>解决方案：
因此，您的Hibernate配置文件将只映射ClassLoadingException文件：
Employee.hbmHibernate Docs：
您可以查看Hibernate Configuration File Example和Using Native Hibernate APIs and hbm.xml Mappings tutorial了解详情。