Question

我做了一些代码来学习hibernate。它抛出下面的错误。我如何找出问题所在并修复它？ dom4j听起来像是一个XML问题。 hibernate.cfg.xml是问题吗？

Exception in thread "main" java.lang.NoClassDefFoundError: org/dom4j/DocumentException
at com.examscam.model.User.persist(User.java:45)
at com.examscam.model.User.main(User.java:57)
Caused by: java.lang.ClassNotFoundException: org.dom4j.DocumentException
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 2 more

（为什么eclipse没有显示这个“2more”的东西？）

代码 -

package com.examscam.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.tool.hbm2ddl.SchemaExport;


@Entity
public class User {

private Long id;
private String password;

@Id
@GeneratedValue

public Long getId(){
    return id;

}

public void setId(Long id){

    Class c1 = User.class;
    this.id = id;

}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

public static void persist(){

    /* 
     * Contains all the info needed to connect to database, along with
     * info from your JPA annotated class, ie this class. 
    */
    AnnotationConfiguration config = new AnnotationConfiguration();
    config.addAnnotatedClass(User.class);
    config.configure();

    SchemaExport schemaExport = new SchemaExport(config);
    schemaExport.create(true, true);

}


public static void main(String[]args){

    persist();

}

}

XML文件 -

<?xml version = '1.0' encoding='UTF-8' ?>

<!Doctype hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
<session-factory>

<property name = "connection.url">
jdbc:mysql://localhost/examscam
</property>

<property name = "connection.username">
root
</property>

<property name = "connection.password">
password
</property>

<property name = "connection.driver_class">
com.mysql.jdbc.Driver
</property>

<property name = "dialect">
org.hibernate.dialect.MySQLDialect
</property>

<property name = "transaction.factory_class">
org.hibernate.transaction.JDBCTransactionFactory
</property>

<property name = "current_session_context_class">
thread
</property>

<!-- this will show us all the SQL statements-->

<property name = "hibernate.show_sql">
true
</property>

<!-- We dont use any mapping files as of now-->

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

更新

修正上述错误后，出现了新问题 -

我用eclipse制作代码。我添加了代码所需的所有可能的jar，我的代码仍然无效。当我已经添加了sl4fj时，为什么会发生此错误 java.lang.ClassNotFoundException：org.slf4j.impl.StaticLoggerBinder slf4j-api-1.5.8.jar）建立路径？

错误 -

  SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
  SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
  Exception in thread "main" java.lang.NoClassDefFoundError: org/slf4j   
  /impl/StaticLoggerBinder
at org.slf4j.LoggerFactory.getSingleton(LoggerFactory.java:223)
at org.slf4j.LoggerFactory.bind(LoggerFactory.java:120)
at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:111)
at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:269)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:242)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:255)
at org.hibernate.cfg.Configuration.<clinit>(Configuration.java:152)
at com.examscam.model.User.persist(User.java:45)
at com.examscam.model.User.main(User.java:57)
   Caused by: java.lang.ClassNotFoundException: org.slf4j.impl.StaticLoggerBinder
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 9 more

Answer 1

确保dom4j.jar在类路径中。

2你说的话。

当你看到'... 2 more'时，这意味着'由'引发的异常的剩余行与父异常的那一点上的剩余行相同。

Answer 2

在项目的lib中添加dom4j.jar。

java.lang.ClassNotFoundException：org.dom4j.DocumentException

2 个答案: