SpringData JPA复合主键

前言

这次有个需求，给项目角色创建一个模板，在数据库建表时发现，模板表template_project_role的主键需要为复合主键：

 

正文

这里采用@IdClass注解的方式来实现复合主键；

思路

1. 编写一个复合主键类TemplateProjectRoleKey;
2. 通过@IdClass注释在实体中标注复合主键;
3. 在Repository 里标明主键为TemplateProjectRoleKey类；

实现

复合主键类

package com.tlgc.system.mvc.model.projectmanager;

import javax.persistence.Column;
import javax.persistence.Id;

public class TemplateProjectRoleKey implements java.io.Serializable {
    /**构造函数,根据自己的主键修改**/
    public TemplateProjectRoleKey(){

    }
    public TemplateProjectRoleKey(String roleId,String templateId){
        this.roleId = roleId;
        this.templateId = templateId;
    }
    /**构造函数,根据自己的主键修改**/

    /**主键列,根据自己的主键修改**/
    private String roleId;
    private String templateId;

    @Column(name = "template_id", length = 50)
    public String getTemplateId() {
        return templateId;
    }

    public void setTemplateId(String templateId) {
        this.templateId = templateId;
    }

    @Column(name = "role_id", length = 50)
    public String getRoleId() {
        return roleId;
    }

    public void setRoleId(String roleId) {
        this.roleId = roleId;
    }
    /**主键列,根据自己的主键修改**/

    /**重点,重写hashCode 和equals方法**/
    @Override
    public int hashCode() {
        final int PRIME = 31;
        int result = 1;
        /**重点,根据自己的主键修改**/
        result = PRIME * result + ((roleId == null) ? 0 : roleId.hashCode());
        result = PRIME * result + ((templateId == null) ? 0 : templateId.hashCode());
        /**重点,根据自己的主键修改**/
        return result;
    }

    @Override
    public boolean equals(Object obj){
        if(this == obj){
            return true;
        }
        if(obj == null){
            return false;
        }
        if(getClass() != obj.getClass()){
            return false;
        }
        final TemplateProjectRoleKey other = (TemplateProjectRoleKey)obj;
        /**重点,根据自己的主键修改**/
        if(roleId == null){
            if(other.roleId != null){
                return false;
            }
        }else if(!roleId.equals(other.roleId)){
            return false;
        }
        if(templateId == null){
            if(other.templateId != null){
                return false;
            }
        }else if(!templateId.equals(other.templateId)){
            return false;
        }
        /**重点,根据自己的主键修改**/
        return true;
    }
}

实体类

package com.tlgc.system.mvc.model.projectmanager;

import org.hibernate.annotations.DynamicInsert;
import org.hibernate.annotations.DynamicUpdate;
import org.hibernate.annotations.GenericGenerator;

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

@Entity
@Table(name = "template_project_role")
@DynamicInsert(true)
@DynamicUpdate(true)
@IdClass(TemplateProjectRoleKey.class)/**重点，注解@IdClass标注用于标注实体所使用主键规则的类**/
public class TemplateProjectRole  implements Serializable {
    private static final long serialVersionUID = -7509069780835660418L;

    private String roleName;

    /**重点，主键列**/
    private String roleId;
    private String templateId;
    @Id
    @Column(name = "template_id", length = 50)
    public String getTemplateId() {
        return templateId;
    }

    public void setTemplateId(String templateId) {
        this.templateId = templateId;
    }
    @Id
    @Column(name = "role_id", length = 50)
    public String getRoleId() {
        return roleId;
    }

    public void setRoleId(String roleId) {
        this.roleId = roleId;
    }
    /**重点，主键列**/


    @Column(name = "role_name")
    public String getRoleName() {
        return roleName;
    }

    public void setRoleName(String roleName) {
        this.roleName = roleName;
    }
    

}

注意： 
1. @IdClass标注用于标注实体所使用主键规则的类； 

Repository类

标明主键为TemplateProjectRoleKey类，JpaRepository<TemplateProjectRole, TemplateProjectRoleKey>

package com.tlgc.system.mvc.repository.projectmanager;

import com.tlgc.system.mvc.model.projectmanager.TemplateProjectRole;
import com.tlgc.system.mvc.model.projectmanager.TemplateProjectRoleKey;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;

public interface TemplateProjectRoleRepository extends JpaRepository<TemplateProjectRole, TemplateProjectRoleKey>, JpaSpecificationExecutor<TemplateProjectRole> {



}