Hibernate的@GeneratedValue复合键(Hibernate @GeneratedV

问题：

我要地图休眠以下

当我实现用户表是我的错误：

无法设置由User.id的反射设定部字段值

我使用MySQL和ID字段是自动递增

@Entity
@Table(name="users")
public class User implements Serializable
{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue
    private Integer id;

    @Id
    private String username;

    //Other fields  
    public User()
    {

    }

    public User(String username, String email, String firstName,
            String lastName, String password, String authority,
            boolean enabled, boolean reset, boolean deleted) 
    {
        this.username = username;
        this.email = email;
        this.firstName = firstName;
        this.lastName = lastName;
        this.password = password;
        this.authority = authority;
        this.enabled = enabled;
        this.reset = reset;
        this.deleted = deleted;
    }

    public User(int id, String username, String email, String firstName,
            String lastName, String password, String authority,
            boolean enabled, boolean reset, boolean deleted) 
    {
        this.id = id;
        this.username = username;
        this.email = email;
        this.firstName = firstName;
        this.lastName = lastName;
        this.password = password;
        this.authority = authority;
        this.enabled = enabled;
        this.reset = reset;
        this.deleted = deleted;
    }

    public int getId() 
    {
        return id;
    }

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

问题是，在休眠状态，如果我想使用两个主键实体的我不得不使用注释@Embedded，但我不知道如何正确使用它

我可以使用的ID @Transient批注轻松地解决这个问题，但这似乎并没有正确的方法

你能帮我在整理了这一点，请

UPDATE

由于@Prasanna我创建了以下，但仍同样的问题

public class UserPK implements Serializable 
{
/**
     * 
     */
    private static final long serialVersionUID = 1L;


    protected Integer id;
    protected String username;

    public UserPK() 
    {

    }

    public UserPK(Integer id, String username) 
    {
        this.id = id;
        this.username = username;
    }

    @Override
    public int hashCode() 
    {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((id == null) ? 0 : id.hashCode());
        result = prime * result
                + ((username == null) ? 0 : username.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) 
    {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        UserPK other = (UserPK) obj;
        if (id == null) {
            if (other.id != null)
                return false;
        } else if (!id.equals(other.id))
            return false;
        if (username == null) {
            if (other.username != null)
                return false;
        } else if (!username.equals(other.username))
            return false;
        return true;
    }
}

注意：我也更新了我的用户类

@Entity
@IdClass(UserPK.class)
@Table(name="users")
public class User implements Serializable
{

Answer 1:

按照在Hibernate中当前实现，其不可能使用@GeneratedValue复合键，选择使用组合键或单个@GeneratedValue ID。

目前已在休眠与自动生成的部分复合ID的报告的问题- HHH-6044

Answer 2:

很显然，当我在一个复合键使用GeneratedValue出现的诸多问题

卸下GeneratedValue注解解决我的问题

谁能解释这是否足以让MySQL的自动增量选项正常工作

文章来源: Hibernate @GeneratedValue in a composite key