java - org.hibernate.hql.ast.QuerySyntaxException 与 Hibernate

Question

我不熟悉将 Hibernate 与 Java 结合使用。我收到以下异常。我在网上找到的有关此错误的内容似乎没有帮助。有任何想法吗？异常:

java.lang.IllegalArgumentException: org.hibernate.hql.ast.QuerySyntaxException: 

ApplPerfStats is not mapped [select count(c) from ApplPerfStats c]
    at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:601)
    at org.hibernate.ejb.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:96)
    at com.icesoft.icefaces.samples.datatable.jpa.CustomerDAO.findTotalNumberCustomers(CustomerDAO.java:89)
    at com.icesoft.icefaces.samples.datatable.ui.SessionBean.getDataPage(SessionBean.java:189)
    at com.icesoft.icefaces.samples.datatable.ui.SessionBean.access$0(SessionBean.java:185)
    at com.icesoft.icefaces.samples.datatable.ui.SessionBean$LocalDataModel.fetchPage(SessionBean.java:245)
    at com.icesoft.icefaces.samples.datatable.ui.PagedListDataModel.getPage(PagedListDataModel.java:121)
    at com.icesoft.icefaces.samples.datatable.ui.PagedListDataModel.getRowCount(PagedListDataModel.java:100)
    at com.icesoft.faces.component.datapaginator.DataPaginator.isModelResultSet(DataPaginator.java:1091)
    at com.icesoft.faces.component.datapaginator.DataPaginatorRenderer.encodeBegin(DataPaginatorRenderer.java:201)

调用的地方:

@SuppressWarnings("unchecked")
public Long findTotalNumberCustomers() {
    EntityManagerHelper.log("finding number of Customer instances", Level.INFO, null);
    try {
        String queryString = "select count(c) from ApplPerfStats c";
        return (Long) getEntityManager().createQuery(queryString).getSingleResult();
    } catch (RuntimeException re) {
        EntityManagerHelper.log("find number of Appl_perf_stats failed",
                Level.SEVERE, re);
        throw re;
    }
}

映射到数据库表的类:

package com.icesoft.icefaces.samples.datatable.jpa;

import java.sql.Timestamp;

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

@Entity
@Table(name = "Appl_perf_stats", uniqueConstraints = {})
public class ApplPerfStats implements java.io.Serializable {
.....

谢谢，

谭

Answer 1

尝试在 persistence.xml 文件中的 persistence-unit 下添加一个 class 元素。

<?xml version="1.0" encoding="UTF-8"?>
<persistence ...>

    <persistence-unit name="unit">
        <class>com.icesoft.icefaces.samples.datatable.jpa.ApplPerfStats</class>
        ...
     </persistence-unit>
<persistence>

除了 JPA/EntityManager，我没有做更多的事情，所以我不知道是否有办法添加整个包。据我所知，在使用 hibernate.cfg.xml 时，必须直接指定每个持久类。