问题描述：大体思路是这样，我最近在做IOS开发想通过WebService访问服务器端数据库的数据，所以想使用Java搭建一个WebService于是在网上找资料使用Java实现的框架JAX-RS.代码如下：
com.hnu.hibernate.bean包下的Student.java类
package com.hnu.hibernate.bean;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.persistence.OneToMany;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement
@Entity
@Table(name="student")
public class Student {
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private Integer userid;
@Column(name="username")
private String username;
@Column(name="password")
private String password;
@Column(name="realname")
private String realname;
@Column(name="age")
private Integer age;
@Column(name="nationality")
private String nationality;
@Column(name="language")
private String language;
@Column(name="year")
private float year;
@Column(name="studyabroadschool")
private String studyabroadschool;
public Integer getUserid() {
return userid;
}
public void setUserid(Integer userid) {
this.userid = userid;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getRealname() {
return realname;
}
public void setRealname(String realname) {
this.realname = realname;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public String getNationality() {
return nationality;
}
public void setNationality(String nationality) {
this.nationality = nationality;
}
public String getLanguage() {
return language;
}
public void setLanguage(String language) {
this.language = language;
}
public float getYear() {
return year;
}
public void setYear(float year) {
this.year = year;
}
public String getStudyabroadschool() {
return studyabroadschool;
}
public void setStudyabroadschool(String studyabroadschool) {
this.studyabroadschool = studyabroadschool;
}
}
com.hnu.hibernate.dao包
package com.hnu.hibernate.dao;
import java.io.Serializable;
import java.util.List;
import org.hibernate.Session;
import com.hnu.hibernate.util.HibernateSessionFactory;
import com.hnu.hibernate.util.HibernateUtil;
public class BaseDAO {
/**
* 插入数据
*
* @param object
*/
public int create(T object) {
Session session = HibernateSessionFactory.getSession();
try {
session.beginTransaction();
session.persist(object);
session.getTransaction().commit();
} catch (Exception e) {
session.getTransaction().rollback();
return 0;
} finally {
session.close();
}
return 1;
}
/**
* 更新数据库
*
* @param object
*/
public int update(T object) {
Session session = HibernateSessionFactory.getSession();
try {
session.beginTransaction();
session.update(object);
session.getTransaction().commit();
} catch (Exception e) {
session.getTransaction().rollback();
return 0;
} finally {
session.close();
}
return 1;
}
/**
* 从数据库中删除
*
* @param object
*/
public int delete(T object) {
Session session = HibernateSessionFactory.getSession();
try {
session.beginTransaction();
session.delete(object);
session.getTransaction().commit();
} catch (Exception e) {
session.getTransaction().rollback();
return 0;
} finally {
session.close();
}
return 1;
}
/**
* 查找单个Entity Bean
*
* @param clazz
* @param id
* @return
*/
@SuppressWarnings("unchecked")
public T find(Class<? extends T> clazz, Serializable id) {
Session session = HibernateSessionFactory.getSession();
try {
session.beginTransaction();
return (T) session.get(clazz, id);
} finally {
session.getTransaction().commit();
session.close();
}
}
/**
* 查找多个Entity Bean
*
* @param hql
* @return
*/
@SuppressWarnings("unchecked")
public List<T> list(String hql) {
Session session =HibernateSessionFactory.getSession();
try {
session.beginTransaction();
return session.createQuery(hql).list();
} finally {
session.getTransaction().commit();
session.close();
}
}
}
com.hnu.hibernate.bean包下生成的WebService Javabean StudentsResource.java类
package com.hnu.hibernate.bean;
import java.util.List;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import com.hnu.hibernate.dao.BaseDAO;
@Produces("application/xml")
@Path("students")
public class StudentsResource {
private BaseDAO baseDAO=new BaseDAO();
@GET
public List getStudents() {
return baseDAO.list("from Student");
}
}
com.hnu.hibernate.util包下Hibernate获取Session的类 HibernateSessionFactory.java类
package com.hnu.hibernate.util;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
/**
- Configures and provides access to Hibernate sessions, tied to the
- current thread of execution. Follows the Thread Local Session
-
pattern, see {@link http://hibernate.org/42.html }.
*/
public class HibernateSessionFactory {/**
- Location of hibernate.cfg.xml file.
- Location should be on the classpath as Hibernate uses
- #resourceAsStream style lookup for its configuration file.
- The default classpath location of the hibernate config file is
- in the default package. Use #setConfigFile() to update
- the location of the configuration file for the current session.
*/ private static final ThreadLocal threadLocal = new ThreadLocal(); private static org.hibernate.SessionFactory sessionFactory;
private static Configuration configuration = new Configuration();
private static ServiceRegistry serviceRegistry;static {
try {
configuration.configure();
serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
sessionFactory = configuration.buildSessionFactory(serviceRegistry);
} catch (Exception e) {
System.err.println("%%%% Error Creating SessionFactory %%%%");
e.printStackTrace();
}
}
private HibernateSessionFactory() {
}/**
- Returns the ThreadLocal Session instance. Lazy initialize
- the
SessionFactoryif needed. * - @return Session
-
@throws HibernateException
*/
public static Session getSession() throws HibernateException {
Session session = (Session) threadLocal.get();if (session == null || !session.isOpen()) {
if (sessionFactory == null) {
rebuildSessionFactory();
}
session = (sessionFactory != null) ? sessionFactory.openSession()
: null;
threadLocal.set(session);
}return session;
}
/**
- Rebuild hibernate session factory * */ public static void rebuildSessionFactory() { try { configuration.configure(); serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry(); sessionFactory = configuration.buildSessionFactory(serviceRegistry); } catch (Exception e) { System.err.println("%%%% Error Creating SessionFactory %%%%"); e.printStackTrace(); } }
/**
- Close the single hibernate session instance. *
-
@throws HibernateException
*/
public static void closeSession() throws HibernateException {
Session session = (Session) threadLocal.get();
threadLocal.set(null);if (session != null) {
session.close();
}
}
/**
- return session factory * / public static org.hibernate.SessionFactory getSessionFactory() { return sessionFactory; } /*
- return hibernate configuration * */ public static Configuration getConfiguration() { return configuration; }
}
hibernate.cfg.xml部署文件
<?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">
<session-factory>
<property name="hbm2ddl.auto">update</property>
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="connection.url">jdbc:mysql://localhost:3306/vocabularyadaptivetestingsystem?characterEncoding=UTF-8</property>
<property name="connection.username">root</property>
<property name="connection.password">123</property>
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="show_sql">true</property>
<property name="current_session_context_class">thread</property>
<mapping class="com.hnu.hibernate.bean.Student"/>
</session-factory>
使用本地的ApplicationServer使用Hibernate访问数据库没有任何问题。但是一旦把访问Hibernate的方法部署到Tomcat服务器上，访问WebService方法没有问题，但是使用WebService调用如下代码：baseDAO.list("from Student");
就出现了如图所示的错误：
希望各位高手帮忙看一下，搞了好久没搞出来，重分酬谢！
