Question

我想将课程主题映射到主题表。

Themes.java

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;  
import javax.persistence.Table;
import javax.persistence.Column;

public class Themes
{
private int id;
private String theme;
private int orderInfo;
public Themes(String theme,int order_info)
{
    System.out.println("OK");
    this.theme=theme;
    this.orderInfo=order_info;
}
public int getId()
{
    return id;
}

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

public String getTheme()
{
    return theme;
}

public void setTheme(String theme)
{
    this.theme=theme;
}

public int getOrder()
{
    return orderInfo;
}

public void setOrder(int order_info)
{
    this.orderInfo=order_info;
}
}

Themes.hbm.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC 
 "-//Hibernate/Hibernate Mapping DTD//EN"
     "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> 

<hibernate-mapping>
   <class name="Themes" table="themes">
      <meta attribute="class-description">
     This class contains theme details. 
      </meta>
      <id name="id" type="int" column="id">
         <generator class="native"/>
      </id>
      <property name="text" column="text" type="string"/>
      <property name="orderInfo" column="order_info" type="int"/>
   </class>
</hibernate-mapping>

的hibernate.cfg.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration SYSTEM 
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
   <session-factory>
   <property name="hibernate.dialect">
      org.hibernate.dialect.MySQLDialect
   </property>
   <property name="hibernate.connection.driver_class">
      com.mysql.jdbc.Driver
   </property>

   <!-- Assume test is the database name -->
   <property name="hibernate.connection.url">
      jdbc:mysql://localhost/content_templating_data
   </property>
   <property name="hibernate.connection.username">
      root
   </property>
   <property name="hibernate.connection.password">

   </property>

   <!-- List of XML mapping files -->
   <mapping resource="themes.hbm.xml"/>
   <mapping resource="patterns.hbm.xml"/>
   <mapping resource="filler.hbm.xml"/>
   <mapping resource="sentences.hbm.xml"/>

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

我从csv文件中读取内容，并希望使用以下代码插入数据库中。

ManageData.java

import java.io.*;

import org.apache.log4j.BasicConfigurator;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class ManageData {
private static SessionFactory factory;
private static String csvfile="C:\\Users\\ANJANEY\\IdeaProjects\\hiveminds\\src\\file.csv";
private static String line="";
private static String splitby=",";
private static BufferedReader br=null;

private static SessionFactory getSessionFactory() {
    // create configuration using hibernate API
    Configuration configuration = new Configuration();
    configuration.setProperty("connection.driver_class",
            "com.mysql.jdbc.Driver");
    configuration.setProperty("hibernate.connection.url",
            "jdbc:mysql://localhost:3306/content_templating_data");
    configuration.setProperty("hibernate.connection.username", "root");
    configuration.setProperty("hibernate.connection.password", "");
    return configuration.buildSessionFactory();
}
public static void main(String args[])throws IOException {
    int count=0;
    try
    {
        factory=getSessionFactory();
        System.out.println("Factory Object created...");


    }
    catch (Throwable ex)
    {
        System.out.println("Failed to create Session Factory Object " + ex);
        //throw new ExceptionInInitializerError();
    }

    try {
        int order_info;
        br = new BufferedReader(new FileReader(csvfile));
        ManageData MD = new ManageData();

        line = br.readLine();
        int length=0;
        while ((line = br.readLine()) != null) {
            count++;
            String[] str = line.split(splitby);
            length=str.length;

            order_info = Integer.parseInt(str[2]);

            //Adding theme details in the theme table
            Integer themeID = MD.addTheme(str[1], order_info);


        }
    }
    catch(FileNotFoundException e)
    {
        e.printStackTrace();
    }catch(IOException e){
        e.printStackTrace();
    }finally{
        if (br != null) {
            try {
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }


    System.out.println("Done "+count);
}

//Method to add in theme table
public Integer addTheme(String theme,int order_info){

    Session session = factory.openSession();
    Transaction tx = null;
    Integer themeID = new Integer(0);

    try{
        tx = session.beginTransaction();

        Themes th=new Themes(theme,order_info);
        themeID = (Integer) session.save(th);
        System.out.println("OKAY");
        tx.commit();

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

我收到以下错误

线程“main”中的异常org.hibernate.MappingException：未知实体：主题 at org.hibernate.impl.SessionFactoryImpl.getEntityPersister（SessionFactoryImpl.java:693）在org.hibernate.impl.SessionImpl.getEntityPersister（SessionImpl.java:1485） at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId（AbstractSaveEventListener.java:120） at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId（DefaultSaveOrUpdateEventListener.java:210） at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId（DefaultSaveEventListener.java:56）在org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient（DefaultSaveOrUpdateEventListener.java:195）在org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate（DefaultSaveEventListener.java:50）在org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate（DefaultSaveOrUpdateEventListener.java:93）在org.hibernate.impl.SessionImpl.fireSave（SessionImpl.java:713）在org.hibernate.impl.SessionImpl.save（SessionImpl.java:701）在org.hibernate.impl.SessionImpl.save（SessionImpl.java:697）在ManageData.addTheme（ManageData.java:114）在ManageData.main（ManageData.java:66） at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method） at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:57） at sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43） at java.lang.reflect.Method.invoke（Method.java:606）在com.intellij.rt.execution.application.AppMain.main（AppMain.java:134）

Answer 1

错误的是你应该将你的包名称添加到Themes.hbm.xml <class name="my.package.Themes" table="themes">而不是<property name="text" column="text" type="string"/> <property name="orderInfo" column="order_info" type="int"/>。

另一个问题是你的映射不等同于你的getter＆amp; setter和fields：

public int getOrderInfo() {
    return orderInfo;
}

public void setOrderInfo(int order_info) {
    this.orderInfo = order_info;
}

文本不存在将其更改为主题。 orderInfo getter / setter应如下所示：

<hibernate-mapping package="my.package">
<class name="Themes" table="themes">
 ....
 </hibernate-mapping>

比主题课适合我。

€dit：你也可以使用类似的东西。

{{1}}

Hibernate映射异常：未知映射实体：主题

1 个答案: