我正在尝试在我的 project 上使用 Hibernate <>

START SCRIPT!
org.hibernate.property.access.spi.PropertyAccessException: Error accessing field [private java.util.Date centaurus.domain.User.created] by reflection for persistent property [centaurus.domain.User#created] : User{id=0, email='test', created=Wed Jun 08 13:06:53 BST 2016}
    at org.hibernate.property.access.spi.GetterFieldImpl.get(GetterFieldImpl.java:43)
    at org.hibernate.property.access.spi.GetterFieldImpl.getForInsert(GetterFieldImpl.java:58)
    at org.hibernate.tuple.entity.AbstractEntityTuplizer.getPropertyValuesToInsert(AbstractEntityTuplizer.java:521)
    at org.hibernate.tuple.entity.PojoEntityTuplizer.getPropertyValuesToInsert(PojoEntityTuplizer.java:228)
    at org.hibernate.persister.entity.AbstractEntityPersister.getPropertyValuesToInsert(AbstractEntityPersister.java:4701)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:254)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:182)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:113)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)
    at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)
    at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
    at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:682)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:674)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:669)
    at centaurus.service.player.PlayerDAOimpl.saveUser(PlayerDAOimpl.java:32)
    at centaurus.Dbmaintain.start(Dbmaintain.java:25)
    at restx.factory.Factory.start(Factory.java:846)
    at restx.RestxMainRouterFactory.build(RestxMainRouterFactory.java:450)
    at restx.RestxMainRouterFactory.newInstance(RestxMainRouterFactory.java:70)
    at restx.servlet.RestxMainRouterServlet.init(RestxMainRouterServlet.java:74)
    at org.eclipse.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:519)
    at org.eclipse.jetty.servlet.ServletHolder.doStart(ServletHolder.java:331)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
    at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:747)
    at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:265)
    at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
    at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:706)
    at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:492)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
    at org.eclipse.jetty.server.handler.HandlerCollection.doStart(HandlerCollection.java:229)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
    at org.eclipse.jetty.server.handler.HandlerCollection.doStart(HandlerCollection.java:229)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
    at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:95)
    at org.eclipse.jetty.server.Server.doStart(Server.java:277)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
    at restx.server.JettyWebServer.start(JettyWebServer.java:109)
    at restx.server.JettyWebServer.startAndAwait(JettyWebServer.java:114)
    at centaurus.AppServer.main(AppServer.java:30)
Caused by: java.lang.IllegalArgumentException: Can not set java.util.Date field centaurus.domain.User.created to centaurus.domain.User
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:164)
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:168)
    at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:55)
    at sun.reflect.UnsafeObjectFieldAccessorImpl.get(UnsafeObjectFieldAccessorImpl.java:36)
    at java.lang.reflect.Field.get(Field.java:379)
    at org.hibernate.property.access.spi.GetterFieldImpl.get(GetterFieldImpl.java:39)
    ... 40 more
2016-06-08 13:06:53,232 [main            ] [          ] INFO  restx.monitor.MetricsConfiguration - registering Metrics JVM metrics

我已经逐步执行了我的程序，它似乎有一个有效的对象通过了 hibernate 保存函数，但在它内部的某个地方抛出了一个错误。我曾尝试删除创建的字段，此时它会提示一个具有相同错误的字符串字段，并试图将其设置为 Player 对象本身。

这是我的 DAOimpl.class

package centaurus.dao.user;

import centaurus.domain.User;

import centaurus.service.HibernateUtils;
import restx.factory.Component;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Transaction;

import javax.inject.Named;
import java.util.List;

@Component
public class UserDAOimpl implements UserDAO {
    private static HibernateUtils hibernateUtils;

    public UserDAOimpl(@Named("HibernateUtils") HibernateUtils hibernateUtils) {
        this.hibernateUtils = hibernateUtils;
    }

    public User saveUser(User user){
        Session session = hibernateUtils.getFactory().openSession();
        Transaction tx = null;
        Integer playerID = null;
        try{
            tx = session.beginTransaction();
            //playerID = (Integer) session.save(user);
            session.save(user);

            tx.commit();

        }catch (HibernateException e) {
            if (tx!=null) tx.rollback();
            e.printStackTrace();
        }finally {
            session.close();
        }
        return user;
    }

    public User getUser(int playerId){
        Session session = hibernateUtils.getFactory().openSession();
        try{
            User user = (User)session.get(User.class, playerId);
            return user;
        }catch (HibernateException e) {

        }finally {
            session.close();
        }
        return null;
    }

    public List<User> getUsers(){
        Session session = hibernateUtils.getFactory().openSession();
        List<User> list = null;
        try{
            list = session.createCriteria(User.class).list();

        }catch (HibernateException e) {

        }finally {
            session.close();
        }
        return list;
    }
}

我在谷歌上搜索了又搜索，尝试了尽可能多的 hibernate 教程，但我仍然遇到这个问题。我不明白为什么 hibernate 试图将一个字段设置为一个对象，我有我的注释。

incase its want here is my domain object player:

package centaurus.domain;

import javax.persistence.*;
import java.io.Serializable;
import java.util.Calendar;
import java.util.Date;

@Entity
@Table(name="users")
public class User implements Serializable{

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name="USER_ID")
    private int id = 0;

    @Column(name="EMAIL")
    private String email = "";

    @Column(name="CREATED")
    private Date created = null;

    public User(){
        Calendar cal = Calendar.getInstance();
        this.created = cal.getTime();
    };

    public User(int id, String email, Date created) {
        this.id = id;
        this.email = email;
        this.created = created;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

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

    public int getId() {
        return id;
    }

    public Date getCreated() {
        return created;
    }

    public void setCreated(Date created) {
        this.created = created;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", email='" + email + '\'' +
                ", created=" + created +
                '}';
    }
} 

这是调用类:

package centaurus;

import centaurus.dao.user.UserDAO;
import centaurus.domain.User;
import restx.factory.AutoStartable;
import restx.factory.Component;

import javax.inject.Named;


@Component
public class DBMaintain implements AutoStartable{
    private UserDAO userDAO;

    public DBMaintain(@Named("UserDAOimpl") UserDAO userDAO) {
        this.userDAO = userDAO;
    }

    public void start(){
        System.out.println("START SCRIPT!");

        //test
        User p = new User();
        p.setEmail("test");
        userDAO.saveUser(p);

    }
}

请问有谁知道如何解决这个问题，谢谢。

编辑:(添加了 sql)

CREATE TABLE Users(
    USER_ID int NOT NULL AUTO_INCREMENT,
    CREATED TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    EMAIL varchar(45) DEFAULT NULL,
    PRIMARY KEY (USER_ID)
);

编辑添加了 hibernate 配置 /src/main/resources/hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!-- Database connection properties - Driver, URL, user, password -->
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost/andromeda</property>
        <property name="hibernate.connection.username">api</property>
        <property name="hibernate.connection.password">apipassword</property>
        <!-- Connection Pool Size -->
        <property name="hibernate.connection.pool_size">1</property>

        <!-- org.hibernate.HibernateException: No CurrentSessionContext configured! -->
        <property name="hibernate.current_session_context_class">thread</property>

        <!-- Outputs the SQL queries, should be disabled in Production -->
        <property name="hibernate.show_sql">true</property>

        <!-- Dialect is required to let Hibernate know the Database Type, MySQL, Oracle etc
            Hibernate 4 automatically figure out Dialect from Database Connection Metadata -->
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>


        <mapping class="centaurus.domain.User"/>
    </session-factory>
</hibernate-configuration>

最佳答案

不确定这是否是答案，但我们拭目以待!

尝试替换

CREATED TIMESTAMP DEFAULT CURRENT_TIMESTAMP

与

CREATED DATETIME DEFAULT CURRENT_DATETIME,

看 SQL 中 Timestamp 和 Datetime 的区别是 TIMESTAMP 值从当前时区转换为 UTC 进行存储，并从 UTC 转换回当前时区进行检索。 (这只发生在 TIMESTAMP 数据类型上，其他类型如 DATETIME 不会发生。) 如果您存储一个 TIMESTAMP 值，然后更改时区并检索该值，则检索到的值与您存储的值不同。 TimeStamp MySQL

DATETIME 表示日期(如日历中所示)和时间(可在挂钟上观察)，

由于您不能将 Java Date 存储到 SQL TIMESTAMP 对象中，因此要么将 SQL TIMESTAMP 更改为 DATETIME，要么更改

private Date created;

到

private Timestamp created;

//And convert your Date to TimeStamp
public User(){
    Date date = new Date();
    created = new Timestamp(date .getTime());
}

希望这对您有所帮助!

关于java - Hibernate DAO 将对象值设置为对象，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37656627/