Question

我有两个实体，其中一个我正在使用用户输入的PK。

启动springboot app时，我收到以下异常。

启动ApplicationContext时出错。显示自动配置报告使用＆＃39; debug＆＃39;重新运行您的应用程序启用。 2017年9月28日 22：06：13.718 $ threadId：1 ERROR namespace：com.shop.tush o.s.b.SpringApplication [主机名：tusbanne.in.ibm.com serviceName：shoppingdetails版本：0.0.1-SNAPSHOT transactionId： conversationId：requestTimeStamp：responseTimeStamp：duration：] 应用启动失败 org.springframework.beans.factory.BeanCreationException：错误创建名为＆entityManagerFactory＆＃39;的bean在类路径中定义 resource [com / shop / tush / DataConfiguration.class]：init的调用方法失败;嵌套异常是org.hibernate.AnnotationException： mappedBy引用未知的目标实体属性： com.shop.tush.model.Department.employee in com.shop.tush.model.Employee.departments at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean（AbstractAutowireCapableBeanFactory.java:1628）在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean（AbstractAutowireCapableBeanFactory.java:555）在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean（AbstractAutowireCapableBeanFactory.java:483）在 org.springframework.beans.factory.support.AbstractBeanFactory $ 1.getObject（AbstractBeanFactory.java:306）在 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton（DefaultSingletonBeanRegistry.java:230）在 org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean（AbstractBeanFactory.java:302）在 org.springframework.beans.factory.support.AbstractBeanFactory.getBean（AbstractBeanFactory.java:197）在 org.springframework.context.support.AbstractApplicationContext.getBean（AbstractApplicationContext.java:1081）在 org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization（AbstractApplicationContext.java:856）在 org.springframework.context.support.AbstractApplicationContext.refresh（AbstractApplicationContext.java:542）在 org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh（EmbeddedWebApplicationContext.java:122）在 org.springframework.boot.SpringApplication.refresh（SpringApplication.java:737）在 org.springframework.boot.SpringApplication.refreshContext（SpringApplication.java:370）在 org.springframework.boot.SpringApplication.run（SpringApplication.java:314）在 org.springframework.boot.SpringApplication.run（SpringApplication.java:1162）在 org.springframework.boot.SpringApplication.run（SpringApplication.java:1151）在com.shop.tush.Application.main（Application.java:70）引起： org.hibernate.AnnotationException：mappedBy引用一个未知的目标实体属性：com.shop.tush.model.Department.employee in com.shop.tush.model.Employee.departments at org.hibernate.cfg.annotations.CollectionBinder.bindStarToManySecondPass（CollectionBinder.java:769）在 org.hibernate.cfg.annotations.CollectionBinder $ 1.secondPass（CollectionBinder.java:719）在 org.hibernate.cfg.CollectionSecondPass.doSecondPass（CollectionSecondPass.java:54）在 org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses（InFlightMetadataCollectorImpl.java:1655）在 org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses（InFlightMetadataCollectorImpl.java:1623）在 org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete（MetadataBuildingProcess.java:278）在 org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata（EntityManagerFactoryBuilderImpl.java:847）在 org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build（EntityManagerFactoryBuilderImpl.java:874）在 org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory（SpringHibernateJpaPersistenceProvider.java:60）在 org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory（LocalContainerEntityManagerFactoryBean.java:353）在 org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory（AbstractEntityManagerFactoryBean.java:370）在 org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet（AbstractEntityManagerFactoryBean.java:359）在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods（AbstractAutowireCapableBeanFactory.java:1687）在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean（AbstractAutowireCapableBeanFactory.java:1624） ...省略了16个常见帧

我的实体类如下。

import java.util.HashSet;
import java.util.Set;

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

@Entity
@Table(name="EMPLOYEE")
public class Employee {

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

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

    @OneToMany(mappedBy = "employee")
    private Set<Department> departments = new HashSet<Department>();

    public Employee(String name, String phoneNumber, Set<Department> department) {
        super();
        this.name = name;
        this.phoneNumber = phoneNumber;
        this.departments = department;
    }

    public String getName() {
        return name;
    }

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

    public String getPhoneNumber() {
        return phoneNumber;
    }

    public void setPhoneNumber(String phoneNumber) {
        this.phoneNumber = phoneNumber;
    }

    public Set<Department> getDepartment() {
        return departments;
    }

    public void setDepartment(Set<Department> department) {
        this.departments = department;
    }

    //equals and hashcode methods overriden



}


import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQuery;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;

@Entity
@Table(name="DEPARTMENT")
public class Department {

    @Id
    @Column(name="ID")
    @SequenceGenerator(name="seq",sequenceName="dept_seq", allocationSize=1)
    @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="seq")
    private Long deptId;

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

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

    @ManyToOne
    @JoinColumn(name = "NAME", nullable = false)
    private Employee employee;


    public Department(Long deptId, String deptName, String deptBoss, Employee employee) {
        super();
        this.deptName = deptName;
        this.deptBoss = deptBoss;
        this.employee = employee;
    }

    public Long getDeptId() {
        return deptId;
    }

    public void setDeptId(Long deptId) {
        this.deptId = deptId;
    }

    public String getDeptName() {
        return deptName;
    }

    public void setDeptName(String deptName) {
        this.deptName = deptName;
    }

    public String getDeptBoss() {
        return deptBoss;
    }

    public void setDeptBoss(String deptBoss) {
        this.deptBoss = deptBoss;
    }

    public Employee getEmployee() {
        return employee;
    }

    public void setEmployee(Employee employee) {
        this.employee = employee;
    }


    //OVERRIDE EQUALS AND HASHCODE

}

我无法在代码中找出问题。

Answer 1

AFAIK Hibernate需要每个实体的no-arg构造函数。由于Employee和Department都定义了显式构造函数，因此必须定义no-arg构造函数

Answer 2

删除

@OneToMany(mappedBy = "employee")
private Set<Department> departments = new HashSet<Department>();

由于您不需要它们，还有一件事只是将所有表格名称保留为小写，这是最佳做法之一。我认为这样可以解决您的问题。

获取mappedBy在应用启动时引用未知的目标实体属性异常

2 个答案: