java - GWT 中的 hibernate 错误

Question

我遇到 hibernate 错误。我只是做一个概念验证来测试 hibernate 中的关联。我几乎可以肯定我认为的错误存在于映射文件中，但我无法弄清楚

我使用的示例是一个用户可以拥有多台计算机，但一台计算机只能供一个用户使用

我的 ModuleLoad 有点类似于 Java 中的 main

public void onModuleLoad() 
    {
        GreetingServiceAsync S = GWT.create(GreetingService.class);
        ((ServiceDefTarget) S).setServiceEntryPoint( GWT.getModuleBaseURL() +"greet");

        Computer C1= new Computer(1,"ad");
        Computer C2= new Computer(2,"ad");
        Computer C3= new Computer(3,"ad");
        Set <Computer> S1= new HashSet();
        S1.add(C2);S1.add(C3);S1.add(C1);

        Users U1= new Users(1,S1);
        S.greetServer(U1, new AsyncCallback <Users>(){

            @Override
            public void onFailure(Throwable caught) {
                // TODO Auto-generated method stub
                Window.alert("Failure");

            }

            @Override
            public void onSuccess(Users result) {
                // TODO Auto-generated method stub
                Window.alert("Success");
            }});

    }

用户类:

    import java.util.HashSet;
    import java.util.List;
    import java.util.Set;

    import net.sf.gilead.pojo.gwt.LightEntity;

    import com.google.gwt.user.client.rpc.IsSerializable;

    public class Users extends LightEntity implements IsSerializable
    {
        private long UserId;
        private Set <Computer> Computers=new HashSet <Computer> ();

        public Users(){}
        public Users(long userId, Set <Computer> computers) 
        {
            UserId = userId;
            Computers = computers;
        }
        public long getUserId() {
            return UserId;
        }
        public void setUserId(long userId) {
            UserId = userId;
        }
        public Set <Computer> getComputers() {
            return Computers;
        }
        public void setComputers(Set<Computer> computers) {
            Computers = computers;
        }
    }

Computer Class:

    import net.sf.gilead.pojo.gwt.LightEntity;

    import com.google.gwt.user.client.rpc.IsSerializable;

    public class Computer extends LightEntity implements IsSerializable
    {
        private long ComputerId;
        private String Description;

        public Computer(){}
        public Computer(long ComputerId,String Description)
        {
            this.ComputerId=ComputerId;
            this.Description=Description;
        }

        public long getComputerId() {
            return ComputerId;
        }
        public void setComputerId(long computerId) {
            ComputerId = computerId;
        }
        public String getDescription() {
            return Description;
        }
        public void setDescription(String description) {
            Description = description;
        }
    }

Users Mapping File:
  <?xml version="1.0"?>
        <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
        <!-- Generated Dec 3, 2010 5:21:42 AM by Hibernate Tools 3.4.0.Beta1 -->
        <hibernate-mapping>
            <class name="com.BiddingSystem.domain.Users" table="USERS">
                <id name="UserId" type="long">
                    <column name="USERID" />
                    <generator class="assigned" />
                </id>
                <set name="Computers" table="COMPUTER" inverse="false" lazy="true">
                    <key>
                        <column name="USERID" />
                    </key>
                    <one-to-many class="com.BiddingSystem.domain.Computer" />
                </set>
            </class>
        </hibernate-mapping>

计算机类:

import net.sf.gilead.pojo.gwt.LightEntity;

import com.google.gwt.user.client.rpc.IsSerializable;

public class Computer extends LightEntity implements IsSerializable
{
    private long ComputerId;
    private String Description;

    public Computer(){}
    public Computer(long ComputerId,String Description)
    {
        this.ComputerId=ComputerId;
        this.Description=Description;
    }

    public long getComputerId() {
        return ComputerId;
    }
    public void setComputerId(long computerId) {
        ComputerId = computerId;
    }
    public String getDescription() {
        return Description;
    }
    public void setDescription(String description) {
        Description = description;
    }
}

计算机映射文件:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated Dec 3, 2010 5:21:42 AM by Hibernate Tools 3.4.0.Beta1 -->
<hibernate-mapping>
    <class name="com.BiddingSystem.domain.Computer" table="COMPUTER">
        <id name="ComputerId" type="long">
            <column name="COMPUTERID" />
            <generator class="assigned" />
        </id>
        <property name="Description" type="java.lang.String">
            <column name="DESCRIPTION" />
        </property>
    </class>
</hibernate-mapping>

hibernate 配置文件:

<?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="hibernate.connection.driver_class">org.postgresql.Driver</property>
        <property name="hibernate.connection.url">jdbc:postgresql://localhost/postgres</property>
        <property name="hibernate.connection.username">postgres</property>
        <property name="hibernate.connection.password">noor</property>
        <property name="hibernate.connection.pool_size">10</property>
        <property name="show_sql">true</property>
        <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
        <property name="hibernate.hbm2ddl.auto">update</property>
        <property name="current_session_context_class">thread</property> 
        <mapping resource="com/BiddingSystem/domain/Users.hbm.xml"/>
        <mapping resource="com/BiddingSystem/domain/Computer.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

服务器实现将其保存到数据库:

import java.util.ArrayList;
import java.util.List;

import net.sf.gilead.core.PersistentBeanManager;
import net.sf.gilead.core.hibernate.HibernateUtil;
import net.sf.gilead.core.store.stateless.StatelessProxyStore;
import net.sf.gilead.gwt.PersistentRemoteService;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

import com.BiddingSystem.client.GreetingService;

import com.BiddingSystem.domain.Users;


import com.google.gwt.user.server.rpc.RemoteServiceServlet;
public class GreetingServiceImpl extends PersistentRemoteService implements GreetingService 
{

    private static final long serialVersionUID = 1L;
    private HibernateUtil gileadHibernateUtil = new HibernateUtil();
    public GreetingServiceImpl ()
    {
         gileadHibernateUtil.setSessionFactory(com.BiddingSystem.server.HibernateUtil.getSessionFactory());

                PersistentBeanManager persistentBeanManager = new PersistentBeanManager();
                persistentBeanManager.setPersistenceUtil(gileadHibernateUtil);
                persistentBeanManager.setProxyStore(new StatelessProxyStore());

                setBeanManager(persistentBeanManager);
    }

    public Users greetServer(Users S) 
    {
        Session session = gileadHibernateUtil.getSessionFactory().openSession();
        Transaction tr= session.beginTransaction();
        session.save(S);
        tr.commit();
        session.close();
         return S;
      }


}

我收到的错误:

Caused by: org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
    at org.hibernate.jdbc.Expectations$BasicExpectation.checkBatched(Expectations.java:85)
    at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:70)
    at org.hibernate.jdbc.BatchingBatcher.checkRowCounts(BatchingBatcher.java:90)
    at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
    at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:183)
    at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
    at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
    at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1206)
    at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:375)
    at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
    at com.BiddingSystem.server.GreetingServiceImpl.greetServer(GreetingServiceImpl.java:44)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at net.sf.gilead.gwt.PersistentRemoteService.processCall(PersistentRemoteService.java:174)
    ... 21 more

用户映射文件:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated Dec 3, 2010 5:21:42 AM by Hibernate Tools 3.4.0.Beta1 -->
<hibernate-mapping>
    <class name="com.BiddingSystem.domain.Users" table="USERS">
        <id name="UserId" type="long">
            <column name="USERID" />
            <generator class="assigned" />
        </id>
        <set name="Computers" table="COMPUTER" inverse="false" lazy="true">
            <key>
                <column name="USERID" />
            </key>
            <one-to-many class="com.BiddingSystem.domain.Computer" />
        </set>
    </class>
</hibernate-mapping>

另一个文件肯定是好的，因为我已经在没有 hibernate 的情况下测试了它们

如果有人能帮忙，那就太好了

Answer 1

使用 hibernate 中指定的生成器，您需要选择一个不同的未保存值来告诉 hibernate 确定是 INSERT 还是 UPDATE。默认实现会检查 id 列是否为空。由于您是手动分配的，因此即使未保存的实体也会有一个 id，并且 Hibernate 将尝试执行更新而不是插入。

阅读 Hibernate documentation 的 ID 部分(特别是 5.1.2.2.5)