解决JPA懒加载的办法

布满荆棘的人生 2024-02-18 21:14 20阅读 0赞

方案1：

1.1、在多的一方的类上加上@ToString()注解，重写toString方法

1.2、在代码中获取一的时候主动调用多的toString()方法：

uopUser.getUserChannelRelationList().toString();

方案2：

2.1、在代码中主动get多的一方的唯一主键：uopUser.getUserChannelRelationList().get\[0\].getId();

1、一对多的类

import lombok.*;
    
    import javax.persistence.*;
    import java.util.List;
    
    @ToString()
    @Entity
    @Getter
    @Setter
    @Builder
    @NoArgsConstructor
    @AllArgsConstructor
    @Table(name = "uop_user")
    public class UopUser {
    
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private Long id;
    
        private String userName;
    
        /**
         * 渠道
         */
        @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY,mappedBy = "uopUser")
        private List<UserChannelRelation> userChannelRelationList;
    
        /**
         * 工业分类
         */
        @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY,mappedBy = "uopUser")
        private List<UserCategoryRelation> userCategoryRelationList;
    
        /**
         *  分部
         */
        @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY,mappedBy = "uopUser")
        private List<UserERPOrganizationFBRelation> userERPOrganizationFBRelationList;
    
        /**
         *  经营部门
         */
        @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY,mappedBy = "uopUser")
        private List<UserERPOrganizationJYRelation> userERPOrganizationJYRelationList;
    
    
    }

2、多的一方

import com.alibaba.fastjson.annotation.JSONType;
    import com.efivestar.weaf.security.domain.ManageUser;
    import com.fasterxml.jackson.annotation.JsonBackReference;
    import com.fasterxml.jackson.annotation.JsonIgnore;
    import lombok.*;
    import org.springframework.validation.annotation.Validated;
    
    import javax.persistence.*;
    import java.util.Date;
    
    @ToString(exclude = "uopUser")
    @JSONType(ignores = "uopUser")
    @Entity
    @Getter
    @Setter
    @Builder
    @NoArgsConstructor
    @AllArgsConstructor
    @Table(name = "user_channel_relation")
    public class UserChannelRelation {
    
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private Long id;
    
        /**
         * 用户
         */
        @JsonIgnore
    //    @JsonBackReference
        @ManyToOne
        @JoinColumn(name = "uop_user_id")
        private UopUser uopUser;
    
        /**
         * 渠道
         */
        @JsonIgnore
        @OneToOne(fetch = FetchType.LAZY)
        private Channel channel;
    
        /**
         * 可选状态
         */
        @Column(nullable = true)
        @Builder.Default
        private boolean checkFlag = false;
    
        /**
         * 修改时间
         */
        @Column(name = "update_time")
        private Date updateTime;
    }