Hibernate-回滚:org.hibernate.MappingException:未知实体 [英] Hibernate - Rollback: org.hibernate.MappingException: Unknown entity

问题描述

我写了一些代码将数据插入SQL数据库.实际上，我正在尝试使用Hibernate学习Struts 2.但是，很遗憾，提交表格后我遇到了问题.

I have written few codes for inserting data into my SQL database. Actually, I am trying to learn Struts 2 with Hibernate. But, unfortunately I am facing a problem after submitting my form.

我找不到此错误消息的原因.我的尝试捕获块抛出错误，如:

I could not find the reason for this error message. My try & catch block throws error like:

Exception in saveOrUpdate() Rollback  :org.hibernate.MappingException: Unknown entity: v.esoft.pojos.Employee

Pojo( Employee.java ):

Pojo(Employee.java):

@Entity
@Table(name = "employee", catalog = "eventusdb")
public class Employee implements java.io.Serializable {

    private Integer empId;
    private String name;
    private String website;

    public Employee() {
    }

    public Employee(String name, String website) {
        this.name = name;
        this.website = website;
    }

    @Id
    @GeneratedValue(strategy = IDENTITY)
    @Column(name = "emp_id", unique = true, nullable = false)
    public Integer getEmpId() {
        return this.empId;
    }

    public void setEmpId(Integer empId) {
        this.empId = empId;
    }

    @Column(name = "name", nullable = false)
    public String getName() {
        return this.name;
    }

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

    @Column(name = "website", nullable = false, length = 65535)
    public String getWebsite() {
        return this.website;
    }

    public void setWebsite(String website) {
        this.website = website;
    }

}

还具有 Employee.hbm.xml :

also having Employee.hbm.xml:

    <?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 Sep 10, 2013 4:29:04 PM by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
    <class name="v.esoft.pojos.Employee" table="employee" catalog="eventusdb">
        <id name="empId" type="java.lang.Integer">
            <column name="emp_id" />
            <generator class="identity" />
        </id>
        <property name="name" type="string">
            <column name="name" not-null="true" />
        </property>
        <property name="website" type="string">
            <column name="website" length="65535" not-null="true" />
        </property>
    </class>
</hibernate-mapping>

推荐答案

如果未映射实体，则应检查休眠配置.Hibernate是ORM框架，用于将pojo(实体)映射到数据库架构对象.您没有配置或休眠找不到对象 Employee 的映射.配置文件为 hibernate.cfg.xml ，应包含到资源 Employee.hbm.xml 的映射.假设此文件与 Employee 类位于同一文件夹中.那么映射将是

If the entity isn't mapped, you should inspect the hibernate configuration. Hibernate is ORM framework used to map pojos (entities) to the database schema objects. You didn't configure or hibernate couldn't find mapping for the object Employee. The configuration file is hibernate.cfg.xml should contain the mapping to the resource Employee.hbm.xml. Suppose this file is in the same folder as Employee class. Then the mapping will be

<mapping resource="v/esoft/pojos/Employee.hbm.xml"/>

另一种方法，如果您使用基于注释的配置，则应使用 class 属性映射到包含Hibernate/JPA注释的pojo.

Another approach if you used an annotation based configuration, then you should use class attribute to map to the pojo that contains Hibernate/JPA annotations.

<mapping class="v.esoft.pojos.Employee"/>

请注意，基于注释的 Configuration 可能会有所不同，具体取决于Hibernate的版本，并且可能需要其他库.

Note, annotation based Configuration might be different depending on version of Hibernate and may require additional libraries.

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