hibernate 的简单问题
我根据教学视频写了一个hibernate的helloworld测试项目：先是一个Student类：
package com.hibernate.model;
public class Student {
private int id;
private String name;
private int age;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
hibernate.cfg.xml代码：
<?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>
<!-- Database connection settings -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost/hibernate</property>
<property name="connection.username">root</property>
<property name="connection.password">root</property>
<!-- JDBC connection pool (use the built-in) -->
<!-- <property name="connection.pool_size">1</property>-->
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- Enable Hibernate's automatic session context management -->
<!-- <property name="current_session_context_class>thread</property>-->
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<!-- Drop and re-create the database schema on startup -->
<!-- <property name="hbm2ddl.auto">update</property> -->
<mapping resource="com/hibernate/model/Student.hbm.xml" />
</session-factory>
</hibernate-configuration>
Student.hbm.xml代码：
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.hibernate.model">
<class name="Student">
<id name="id"></id>
<property name="name"></property>
<property name="age"></property>
</class>
</hibernate-mapping>
StudentTest代码：
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import com.hibernate.model.Student;
public class StudentTest {
public static void main(String[] args) {
Student s=new Student();
s.setId(1);
s.setName("s1");
s.setAge(1);
Configuration cfg=new Configuration();
SessionFactory sf=cfg.configure().buildSessionFactory();
Session session=sf.openSession();
session.beginTransaction();
session.save(s);
session.getTransaction().commit();
session.close();
sf.close();
}
}
运行后老是出错：
Exception in thread "main" java.lang.NoClassDefFoundError: javax/persistence/EntityListeners
at org.hibernate.cfg.annotations.reflection.JPAMetadataProvider.getDefaults(JPAMetadataProvider.java:96)
at org.hibernate.annotations.common.reflection.java.JavaReflectionManager.getDefaults(JavaReflectionManager.java:226)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1385)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1856)
at StudentTest.main(StudentTest.java:16)
Caused by: java.lang.ClassNotFoundException: javax.persistence.EntityListeners
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
... 5 more
有关hibernate的jar包我都导进去了的，还是有错，请各位高手指点一下，为什么？
[解决办法]
只要是noClassDefFoundError，大部分都是你有jar檔沒有加進來。
看log，應該是你的JPA的實現沒有，你只要加了JPA的接口的包，沒有實現的包，所以錯了。
Configuration cfg = new Configuration();
SessionFactory sf = cfg.configure().buildSessionFactory();
Session session = sf.openSession();
Transaction tr = session.beginTransaction(); <== 發生錯誤的程式
session.save(u);
// session.getTransaction().commit();
tr.commit();
session.close();
sf.close();
Exception in thread "main" java.lang.NoClassDefFoundError: javax/persistence/EntityListeners
at org.hibernate.cfg.annotations.reflection.JPAMetadataProvider.getDefaults(JPAMetadataProvider.java:96)
at org.hibernate.annotations.common.reflection.java.JavaReflectionManager.getDefaults(JavaReflectionManager.java:226)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1355)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1826)
at company.service.SampleService.main(SampleService.java:24)
Caused by: java.lang.ClassNotFoundException: javax.persistence.EntityListeners
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
... 5 more
錯誤原因是：沒有annotation的包，
hibernate3.4版前要加載3個包:hibernate-annotations.jar,ejb3-persistence.jar,hibernate-commons-annotations.jar
之後的版本就只需要加載一個包了：hibernate-jpa-2.0-api-1.0.0.Final.jar
我的异常网推荐解决方案：java.lang.ClassNotFoundException: javax.persistence.EntityListeners,http://www.myexception.cn/j2ee/182645.html
