java - Hibernate 持久错误，id 字段为空

Question

嗨，我正在尝试进行持久化，但看起来好像从未设置过其中一个属性，但是，在进行持久化之前，我打印了值并进行了设置。我正在与 postgrest 合作

我的坚持方法

  public void saveText(Document document){

    sessionFactory = new Configuration().configure().buildSessionFactory();

    Session session = sessionFactory.getCurrentSession();

    System.out.println(document.getText());
    System.out.println(document.getId());

    try {
        session.beginTransaction();
        session.persist(document);
        session.getTransaction().commit();
    }
    catch (HibernateException e) {
        e.printStackTrace();
        session.getTransaction().rollback();
    }
}

我反对坚持下去

import java.io.Serializable;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import br.com.symsar.sysged.acessobd.AccesData;

@Entity
@ManagedBean
@SessionScoped
@Table(name = "documents", schema = "public")
public class Document implements Serializable {

private static final long serialVersionUID = 1L;

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "\"id\"")
private int id;
@Column(name = "\"text\"")
private String text;

public void persist() {
    AccesData access = new AccesData();
    access.saveText(this);
}

/**
 * @return the text
 */
public String getText() {
    return text;
}

/**
 * @param text
 *            the text to set
 */
public void setText(String text) {
    this.text = text;
}

public Integer getId() {
    return id;
}

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

}

hibernate显示的Sql查询

Hibernate: insert into public.documents ("id", "text") values (null, ?)

这是错误:

ERROR: ERRO: Null value in the column "id" violates not-null constraint

Answer 1

字段id在实体类中有JPA注释@Id。这意味着它不能为 null。尝试插入不带 id 参数的值:

Hibernate: insert into public.documents ("text") values (?)