UserPost.java

import com.pranay.blog.entities.compositekey.UserPostId;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

import javax.persistence.*;
import java.io.Serializable;

@Data
@Entity
@Table(name = "user_post")
@AllArgsConstructor
@NoArgsConstructor
@IdClass(UserPostId.class)
public class UserPost implements Serializable {

    private static final long serialVersionUID = -909206262878526790L;
  
  
    @Id
    @Column(name = "user_id")
    private Integer userId;

    @Id
    @Column(name = "post_id")
    private Integer postId;

}

UserPostId.java

import lombok.Data;
import lombok.EqualsAndHashCode;
import lombok.NoArgsConstructor;

import java.io.Serializable;

@Data
@NoArgsConstructor
@EqualsAndHashCode
public class UserPostId implements Serializable {
    private static final long serialVersionUID = 2702030623316532366L;

    private Integer userId;
    private Integer postId;

}