javax.ejb.EJBTransactionRolledbackException的findAll

Question

我試圖創建使用MySQL和Hibernate簡單JPA aplication，我想從表學生 db table

負載4分的記錄，但我收到此錯誤：

Exception in thread "main" javax.ejb.EJBTransactionRolledbackException: Named query not found: findAll 

這裏是我的實體類

package entity; 

import javax.persistence.Column; 
import javax.persistence.Entity; 
import javax.persistence.GeneratedValue; 
import javax.persistence.GenerationType; 
import javax.persistence.Id; 
import javax.persistence.NamedQueries; 
import javax.persistence.NamedQuery; 
import javax.persistence.Table; 

@Entity 
@Table(name="student") 
@NamedQueries({ 
    @NamedQuery(name = "findAll", query = "select st from student st") 
    }) 
public class student{ 

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

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

    @Column(name="surname") 
    private String surname; 

    @Column(name="sex") 
    private String sex; 

    public student(String name, String surname, String sex) { 
     this.name = name; 
     this.surname = surname; 
     this.sex = sex; 
    } 

    public int getId() { 
     return id; 
    } 

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

    public String getName() { 
     return name; 
    } 

    public void setName(String name) { 
     this.name = name; 
    } 

    public String getSurname() { 
     return surname; 
    } 

    public void setSurname(String surname) { 
     this.surname = surname; 
    } 

    public String getSex() { 
     return sex; 
    } 

    public void setSex(String sex) { 
     this.sex = sex; 
    } 

    @Override 
    public String toString() { 
     return "student [id=" + id + ", name=" + name + ", surname=" + surname + ", sex=" + sex + "]"; 

} 

DAO

package dao; 

import java.util.List; 

import javax.persistence.EntityManager; 
import javax.persistence.Query; 
import javax.persistence.TypedQuery; 

import entity.student; 

public class StudentDAO { 

    public List<student> getAllStd(EntityManager em){ 
     TypedQuery<student> q = em.createNamedQuery("findAll", student.class); 
     return q.getResultList();  
    }  
} 

終於豆調用DAO方法

package test; 

import java.util.List; 

import javax.ejb.Stateless; 
import javax.persistence.EntityManager; 
import javax.persistence.PersistenceContext; 
import javax.persistence.TypedQuery; 

import dao.StudentDAO; 
import entity.student; 

@Stateless 
public class Test2Bean { 

    @PersistenceContext() 
    private EntityManager em;  

    public void getAllStudents(){ 
     StudentDAO stdDAO = new StudentDAO(); 
     List<student> students = stdDAO.getAllStd(em); 
     System.out.println(students.size()); 
    }  
} 

的persistence.xml

<?xml version="1.0" encoding="UTF-8"?> 
<persistence version="2.0" 
xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation=" 
http://java.sun.com/xml/ns/persistence 
http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"> 
<persistence-unit name="mysql"> 
<provider>org.hibernate.ejb.HibernatePersistence</provider> 
<jta-data-source>java:jboss/mysqlds</jta-data-source> 
<exclude-unlisted-classes>false</exclude-unlisted-classes> 
<properties> 

<property name="hibernate.show_sql" value="true" /> 
<property name="hibernate.hbm2ddl.auto" value="update" /> 
<property name="hibernate.use_sql_comments" value="true" /> 
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" /> 
</properties> 

</persistence-unit> 

</persistence> 

我不知道爲什麼DAO方法斜面訪問查詢，我做了一些測試方法在實體類和DAO方法可以訪問實體學生。

• 我全加的錯誤消息http://pastebin.com/agBxHg7K

感謝所有答案

Answer 1

嘗試...

@Entity 
@Table(name="student") 
@NamedQueries({ 
@NamedQuery(name = "Student.findAll", query = "select st from student st") 
}) 
public class student{ 

添加學生。之前「findAll」

不知道是否這是它，但我的命名查詢通常有這樣的。