Spring + Hibernate：我無法刪除表中的記錄

我在Spring領域頗爲新穎，在這段時間我正在研究如何將它與Hibernate集成以創建我的DAO對象，但我發現一些難度與DELETE操作...Spring + Hibernate：我無法刪除表中的記錄

所以我有一個表的人，我有創建實現我的DAO對象這個具體類：

package org.andrea.myexample.HibernateOnSpring.dao; 

import java.util.List; 

import org.andrea.myexample.HibernateOnSpring.entity.Person; 
import org.hibernate.Criteria; 
import org.hibernate.Session; 
import org.hibernate.SessionFactory; 
import org.springframework.transaction.annotation.Transactional; 

public class PersonDAOImpl implements PersonDAO { 

private SessionFactory sessionFactory; 

public void setSessionFactory(SessionFactory sessionFactory) { 
    this.sessionFactory = sessionFactory; 
} 

// Metodo che inserisce un nuovo record nella tabella person 
@Transactional(readOnly = false) 
public void addPerson(Person p) { 
    Session session = sessionFactory.openSession(); 
    session.save(p); 
    session.close(); 
} 

/* 
* Metodo che recupera un record, rappresentante una persona, avente uno 
* specifico id dalla tabella. 
* 
* @param L'id univoco della persona 
*/ 

public Person getById(int id) { 
    Session session = sessionFactory.openSession(); 
    try { 
     return (Person) session.get(Person.class, id); 
    } finally { 
     session.close(); 
    } 
} 

/* 
* Metodo che recupera la lista di tutti le persone rappresentanti dalle 
* righe della tabella person 
*/ 
@SuppressWarnings("unchecked") 
public List<Person> getPersonsList() { 

    Session session = sessionFactory.openSession(); 
    try { 

     Criteria criteria = session.createCriteria(Person.class); 
     return criteria.list(); 

    } finally { 
     session.close(); 
    } 

} 

/* 
* Metodo che elimina dalla tabella person la riga avente uno specifico id 
* 
* @param l'id della persona da eliminare dalla tabella person 
*/ 
public void delete(int id) { 

    Session session = sessionFactory.openSession(); 
    try { 
     Person personToDelete = getById(id); 
     session.delete(personToDelete); 

    } finally { 
     session.close(); 
    } 

} 

}

然後，我有創建一個主類，以測試如何吾道工作我沒有問題插入一個新的對象到dable中，以獲得單個對象或所有對象的列表在表中，但我發現問題從表中刪除一個對象。

這是我的測試類：

package org.andrea.myexample.HibernateOnSpring; 

import java.util.List; 

import org.andrea.myexample.HibernateOnSpring.dao.PersonDAO; 
import org.andrea.myexample.HibernateOnSpring.dao.PersonDAOImpl; 
import org.andrea.myexample.HibernateOnSpring.entity.Person; 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.context.ApplicationContext; 
import org.springframework.context.support.ClassPathXmlApplicationContext; 

public class App { 

public static void main(String[] args){ 

    ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml"); 
    System.out.println("Contesto recuperato: " + context); 

    Person persona1 = new Person(); 

    persona1.setFirstname("Pippo"); 
    persona1.setLastname("Blabla"); 
    //persona1.setPid(1); 

    System.out.println("Creato persona1: " + persona1); 

    PersonDAO dao = (PersonDAO) context.getBean("personDAOImpl"); 

    System.out.println("Creato dao object: " + dao); 

    dao.addPerson(persona1); 

    System.out.println("persona1 salvata nel database"); 

    Person personaEstratta = dao.getById(persona1.getPid()); 

    System.out.println("Persona con id: " + personaEstratta.getPid() + " estratta dal DB"); 
    System.out.println("Dati persona estratta:"); 
    System.out.println("Nome: " + personaEstratta.getFirstname()); 
    System.out.println("Cognome: " + personaEstratta.getLastname()); 

    System.out.println(""); 

    // STAMPA LA LISTA DELLE PERSONE NELLA TABELL person: 
    List<Person> listaPersone = dao.getPersonsList(); 
    System.out.println("Lista delle persone recuperata: " + listaPersone); 

    // MOSTRA I DATI DI TUTTE LE PERSONE NELLA LISTA: 
    for(int i=0; i<listaPersone.size(); i++){ 
     Person currentPerson = listaPersone.get(i); 
     System.out.println("id: " + currentPerson.getPid() 
          + " nome: " + currentPerson.getFirstname() 
          + " cognome: " + currentPerson.getLastname()); 
    } 

    // ELIMINAZIONE DI UNA PERSONA DALLA TABELLA person: 
    System.out.println(""); 
    System.out.println("ELIMINAZIONE DI UNA PERSONA DALLA TABELLA person:"); 


    // ELIMINA TUTTI I RECORD DALLA TABELLA persone: 
    for(int i=0; i<listaPersone.size(); i++){ 
     dao.delete(listaPersone.get(i).getPid()); 
     System.out.println("Persona con id: " + i + " eliminata"); 
    } 

    listaPersone = dao.getPersonsList(); // Lista vuota 

    // MOSTRA I DATI DI TUTTE LE PERSONE NELLA LISTA: 
    for(int i=0; i<listaPersone.size(); i++){ 
     Person currentPerson = listaPersone.get(i); 
     System.out.println("id: " + currentPerson.getPid() 
            + " nome: " + currentPerson.getFirstname() 
            + " cognome: " + currentPerson.getLastname());  
    } 

} 
}

在這個類我想刪除所有表記錄執行週期，只需要這樣的結尾：

dao.delete(listaPersone.get(i).getPid());

但不要」噸工作，並在我的表中，所有記錄仍保持不變...

爲什麼？我的代碼有什麼問題？（我也不例外...）

這是我的Person類代碼：

package org.andrea.myexample.HibernateOnSpring.entity; 

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

@Entity 
@Table(name="person") 
public class Person { 

@Id 
@GeneratedValue(strategy=GenerationType.AUTO) 
private int pid; 

private String firstname; 

private String lastname; 

public int getPid() { 
    return pid; 
} 

public void setPid(int pid) { 
    this.pid = pid; 
} 

public String getFirstname() { 
    return firstname; 
} 

public void setFirstname(String firstname) { 
    this.firstname = firstname; 
} 

public String getLastname() { 
    return lastname; 
} 

public void setLastname(String lastname) { 
    this.lastname = lastname; 
} 
}

來源

2013-02-23 AndreaNobili

可以包括代碼對於Person對象也好嗎？ – 2013-02-23 20:24:21

好的，在原來的主題中我添加了人員類代碼 – AndreaNobili 2013-02-23 22:06:45

您是否也可以包含程序的輸出？ – 2013-02-24 18:51:25

從你的代碼似乎挽救工作，但刪除不。我假設會話與事務同步（事務完成前清除會話）。在delete方法上配置@Transactional應該可以工作。

來源

2013-02-23 20:41:55 Adi

添加仍然不工作...我已經在原來的主題 – AndreaNobili 2013-02-23 22:08:07

我在刪除方法上看不到@Transactional？你有沒有一個

來源

2013-02-23 21:19:07 JohnNY

包括人類仍然沒有工作添加...我已經包括人類在原始主題 – AndreaNobili 2013-02-23 22:07:18

爲什麼你不把代碼在github上和我會看看 – JohnNY 2013-02-24 02:48:17

你的刪除方法它看起來像什麼？是否包含@Transaction 這是一個例子：

@Transaction 
public int deleteUser(String userName) { 
    try { 

    //open a session and begin the transaction with the database 
    sessionFactory = HibernateUtil.getSessionFactory(); 
    Session session = sessionFactory.openSession(); 
    session.beginTransaction(); 

    //query the database 
    Query query = session.createQuery("delete from Users u where u.userName ='" + userName +"'"); 
    int result = query.executeUpdate(); 
    session.close(); 

    return result; 
}

確認您的回報statment之前關閉會話

來源

2014-04-06 00:11:12 wolver

如果你'beginTransaction（）'你不需要'commit（）'你的事務??? – KNU 2014-04-06 00:16:37

不，因爲你有@Transactional，現在每個交易都要注意這個註釋;） – wolver 2014-04-14 15:21:35

啊，我從來沒有用過它。這個週末值得測試。 – KNU 2014-04-15 11:08:51

我已經解決了這個問題，這樣的：

@Override 
public void deleteData(int id) { 
    log.info("delete by id = "+id); 
    Transaction tx=null; 

    //open a session and begin the transaction with the database 
    Session session = null; 


    try { 
     session = getSession(); 
     tx = session.beginTransaction(); 
     Person person = getPerson(id); 
     session.delete(person);    
     tx.commit(); 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } finally { 

     if (!tx.wasCommitted()) { 
      tx.rollback(); 
     }//not much doing but a good practice 
     session.flush(); //this is where I think things will start working. 
     session.close(); 
    } 
}

來源

2016-03-10 02:58:38

Spring + Hibernate：我無法刪除表中的記錄

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