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  • 【Mybatis】未封装返回结果的字段自己返回值的问题

    在spring boot中使用mybatis过程中,发现有个实体的时间字段未在mapper方法执行完的封装结果中进行封装,但是却有值返回。

    如下展示问题:

    实体如下:

    package com.sxd.swapping.domain;
    
    import com.sxd.swapping.base.BaseBean;
    import lombok.Getter;
    import lombok.Setter;
    import org.apache.commons.lang3.StringUtils;
    import org.springframework.data.jpa.domain.Specification;
    
    import javax.persistence.Column;
    import javax.persistence.Entity;
    import javax.persistence.Table;
    import javax.persistence.criteria.CriteriaBuilder;
    import javax.persistence.criteria.CriteriaQuery;
    import javax.persistence.criteria.Predicate;
    import javax.persistence.criteria.Root;
    import java.io.Serializable;
    import java.util.*;
    
    @Entity
    @Table
    @Getter
    @Setter
    public class HuaYangArea extends BaseBean implements Serializable {
        private static final long serialVersionUID = -1851783771574739215L;
    
        @Column(nullable = false)
        private String areaName;
    
        @Column(nullable = false)
        private Long areaPerson;
    
    
        public static Specification<HuaYangArea> where(HuaYangArea huaYangArea){
    
            return  new Specification<HuaYangArea>() {
                @Override
                public Predicate toPredicate(Root<HuaYangArea> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) {
                    //创建查询列表
                    List<Predicate> predicates = new ArrayList<>();
    
                    //字段areaName是否查询
                    String areaName = huaYangArea.getAreaName();
                    if (StringUtils.isNotBlank(areaName)){
                        predicates.add(criteriaBuilder.like(root.get("areaName"),"%"+areaName+"%"));
                    }
                    //字段areaPerson是否查询
                    Long areaPerson = huaYangArea.getAreaPerson();
                    if (areaPerson != null) {
                        predicates.add(criteriaBuilder.equal(root.get("areaPerson"),areaPerson));
                    }
    
                    return criteriaQuery.where(predicates.toArray(new Predicate[predicates.size()])).getRestriction();
                }
            };
        }
    
    }
    View Code
    package com.sxd.swapping.base;
    
    import org.springframework.data.domain.PageRequest;
    import org.springframework.data.domain.Sort;
    
    import javax.persistence.*;
    import java.util.*;
    import java.util.stream.Collectors;
    
    /**
     * 基础bean
     */
    @MappedSuperclass
    public class BaseBean {
    
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private Long id;// 主键 自增
    
        @Column(nullable = false, updatable = false)
        private Date createDate = new Date();// 创建时间
    
        private Date updateDate = new Date();// 修改时间
    
        private String updateId; // 修改人
    
        @Column(nullable = false)
        private String createId; // 创建人
    
    
        @Column(nullable = false)
        private String uid;     //业务主键
    
        @Transient
        private Integer pageNum = 0;    //分页 页号
    
        @Transient
        private Integer pageSize = 10;  //分页 页量
    
    
        public Long getId() {
            return id;
        }
    
        public void setId(Long id) {
            this.id = id;
        }
    
        public Date getCreateDate() {
            return createDate;
        }
    
        public void setCreateDate(Date createDate) {
            this.createDate = createDate;
        }
    
        public Date getUpdateDate() {
            return updateDate;
        }
    
        public void setUpdateDate(Date updateDate) {
            this.updateDate = updateDate;
        }
    
        public String getUpdateId() {
            return updateId;
        }
    
        public void setUpdateId(String updateId) {
            this.updateId = updateId;
        }
    
        public String getCreateId() {
            return createId;
        }
    
        public void setCreateId(String createId) {
            this.createId = createId;
        }
    
        public String getUid() {
            return uid;
        }
    
        public void setUid(String uid) {
            this.uid = uid;
        }
    
        public Integer getPageNum() {
            return pageNum;
        }
    
        public void setPageNum(Integer pageNum) {
            this.pageNum = pageNum;
        }
    
        public Integer getPageSize() {
            return pageSize;
        }
    
        public void setPageSize(Integer pageSize) {
            this.pageSize = pageSize;
        }
    
        public void initEntity(){
            this.createDate = new Date();
            this.createId = UUID.randomUUID().toString();//如果有当前登陆人,则初始化为当前登陆人
            this.uid = UUID.randomUUID().toString();
        }
    
        public void updateEntity(){
            this.updateDate = new Date();
            this.updateId = UUID.randomUUID().toString();//如果有当前登陆人,则赋值为当前登陆人
        }
    
        /**
         * 分页 工具方法
         * @return
         */
        public  PageRequest page(){
            return PageRequest.of(pageNum,this.pageSize);
        }
    
        /**
         * 分页 排序工具方法
         *
         * 中文字段排序 需要在查询出来后处理 sort无法解决中文排序的问题
         * @param map
         * @param obj
         * @return
         * @throws Exception
         */
        public  PageRequest page(Map<String,Sort.Direction> map,Object obj) throws Exception{
            //反射获取实体所有属性
            List<String> properties = Arrays.stream(obj.getClass().getDeclaredFields()).map(i->i.getName()).collect(Collectors.toList());
            Set<String> keySet = map.keySet();
            Sort sort = null;
            if (properties.containsAll(keySet)){
                for (String str:keySet){
                    if (sort == null){
                        sort = Sort.by(map.get(str),str);
                    }else{
                        sort = sort.and(Sort.by(map.get(str),str));
                    }
                }
            }else{
                throw new Exception("排序字段非本实体字段");
            }
            return PageRequest.of(this.pageNum,this.pageSize,sort);
        }
    }
    View Code

    Mapper.java如下:

    public interface HuaYangAreaMapper {
    
        /**
         * 根据业务主键查询
         * @param uid
         * @return
         */
        @Select("SELECT * FROM hua_yang_area where uid = #{uid}")
        @Results({
                @Result(property = "areaName",column = "area_name",javaType = String.class),
                @Result(property = "areaPerson",column = "area_person",javaType = Long.class),
                @Result(property = "createId",column = "create_id",javaType = String.class)
        })
        HuaYangArea findOne(String uid);
    View Code

    调用这个方法,返回结果如下:

    如上所示,因为createDate和updateDate都没有在结果集进行封装,所以按道理来说应该是获取不到值的嘛,但是这里却能获取到值。

    ,展示结果集封装

    追溯原因:

    最后找到根源,原来是因为在实体类中,部分不按逻辑出牌的字段 进行了new操作

    所以,如果想要mybatis查询的结果集完全按照自己封装的效果来进行返回,就可以将这里的初始化给去掉!!!!

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  • 原文地址:https://www.cnblogs.com/sxdcgaq8080/p/9050442.html
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