效率提升-再次实践pojo的映射简化（mapStruct）

我会带着你远行 2023-07-21 11:23 13阅读 0赞

# 背景 #

之前写了一个mapStruct的Hello World，本wiki将再用一个实际项目中的例子来进行优化。

# 实现过程 #

## 创建一个spring boot项目 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dhbmdqaWU1NTQw_size_16_color_FFFFFF_t_70]  
这里创建了一个MyApplicationRunner，方便我们调试bean

## 复制之前项目中的代码 ##

我们先看一下两个需要转换的类。  
ClassTaskPO.java

import lombok.Data;
    import lombok.NoArgsConstructor;
    
    import java.sql.Timestamp;
    
    
    /**
     * <p>Description: 班级任务持久化对象类</p>
     *
     * @author wang
     * @date 2018/10/22
     **/
    @Data
    @NoArgsConstructor
    public class ClassTaskPO {
        
        private Long id;
        private Integer oldTaskId;
        private Long templateId;
        private String publisherId;
        private String publisherName;
        private String relation;
        private String classId;
        private String className;
        private String schoolId;
        private String userId;
        private Integer roleType;
        private Integer type;
        private String tags;
        private String title;
        private String image;
        private Integer imageWidth;
        private Integer imageHeight;
        private String coverImage;
        private Integer coverImageWidth;
        private Integer coverImageHeight;
        private String introduction;
        private String content;
        private String remarkContent;
        private Integer origin;
        private Integer totalCount;
        private Integer totalDay;
        private Timestamp startTime;
        private Timestamp endTime;
        private String submitEndTime;
        private Integer state;
        private String students;
        private Integer contentType;
        private Integer visibility;
        private Integer isDelete;
        private Integer isRemark;
        private Long remindTime;
        private Timestamp createTime;
        private Timestamp updateTime;
    
    	// 直接在构造函数中写的转换，缺点是：即使属性名称相同，也得一个一个去写属性匹配（不留神丢一个，就尴尬了）
        public ClassTaskPO(ClassTaskWriteDTO classTaskWriteDTO) {
        
            templateId = classTaskWriteDTO.getTaskTemplateId();
            publisherId = classTaskWriteDTO.getPublisherId();
            // default配置
            publisherName = classTaskWriteDTO.getPublisherName() == null ? "" : classTaskWriteDTO.getPublisherName();
            relation = classTaskWriteDTO.getRelation();
            classId = classTaskWriteDTO.getClassId();
            className = classTaskWriteDTO.getClassName();
            userId = classTaskWriteDTO.getUserId();
            roleType = classTaskWriteDTO.getRoleType();
            schoolId = classTaskWriteDTO.getSchoolId();
            type = classTaskWriteDTO.getType();
            tags = classTaskWriteDTO.getTags();
            title = classTaskWriteDTO.getTitle();
            introduction = classTaskWriteDTO.getIntroduction();
            content = classTaskWriteDTO.getContent();
            remarkContent = classTaskWriteDTO.getRemarkContent();
            origin = classTaskWriteDTO.getOrigin();
            totalCount = classTaskWriteDTO.getTotalCount();
            totalDay = classTaskWriteDTO.getTotalDay();
            // 时间戳转换
            startTime = new Timestamp(classTaskWriteDTO.getStartTime());
            endTime = new Timestamp(classTaskWriteDTO.getEndTime());
            // 时间戳转换
            submitEndTime = classTaskWriteDTO.getSubmitEndTime();
            contentType = classTaskWriteDTO.getContentType();
            visibility = classTaskWriteDTO.getVisibility();
            // 时间戳转换
            startTime = new Timestamp(classTaskWriteDTO.getStartTime());
            state = classTaskWriteDTO.getState();
        }
    
        public ClassTaskPO(ClassTaskUpdateDTO classTaskUpdateDTO) {
        
            id = classTaskUpdateDTO.getTaskId();
            schoolId = classTaskUpdateDTO.getSchoolId();
            tags = classTaskUpdateDTO.getTags();
            title = classTaskUpdateDTO.getTitle();
            introduction = classTaskUpdateDTO.getIntroduction();
            content = classTaskUpdateDTO.getContent();
            submitEndTime = classTaskUpdateDTO.getSubmitEndTime();
            totalCount = classTaskUpdateDTO.getTaskTotalCount();
            totalDay = classTaskUpdateDTO.getTaskTotalDay();
            if (null != classTaskUpdateDTO.getStartTime()) {
        
                startTime = new Timestamp(classTaskUpdateDTO.getStartTime());
            }
            if (null != classTaskUpdateDTO.getEndTime()) {
        
                endTime = new Timestamp(classTaskUpdateDTO.getEndTime());
            }
        }
    
        public ClassTaskPO(ClassTaskDetail classTaskDetail, ClassTaskUpdateDTO classTaskUpdateDTO) {
        
            templateId = classTaskDetail.getTaskTemplateId();
            publisherId = classTaskDetail.getPublisherId();
            publisherName = classTaskDetail.getPublisherName() == null ? "" : classTaskDetail.getPublisherName();
            relation = classTaskDetail.getRelation();
            classId = classTaskDetail.getClassId();
            className = classTaskDetail.getClassName();
            userId = classTaskDetail.getUserId();
            roleType = classTaskDetail.getRoleType();
            schoolId = classTaskDetail.getSchoolId();
            type = classTaskDetail.getType();
            remarkContent = classTaskDetail.getRemarkContent();
            origin = classTaskDetail.getOrigin();
            contentType = classTaskDetail.getContentType();
            visibility = classTaskDetail.getVisibility();
            startTime = new Timestamp(classTaskDetail.getStartTime());
            state = classTaskDetail.getState();
    
            tags = classTaskUpdateDTO.getTags();
            title = classTaskUpdateDTO.getTitle();
            introduction = classTaskUpdateDTO.getIntroduction();
            content = classTaskUpdateDTO.getContent();
            startTime = new Timestamp(classTaskUpdateDTO.getStartTime());
            endTime = new Timestamp(classTaskUpdateDTO.getEndTime());
            submitEndTime = classTaskUpdateDTO.getSubmitEndTime();
            totalCount = classTaskUpdateDTO.getTaskTotalCount();
            totalDay = classTaskUpdateDTO.getTaskTotalDay();
        }
    }

ClassTaskWriteDTO.java

import lombok.Data;
    
    import java.io.Serializable;
    
    /**
     * <p>Description: 班级任务写入传输对象</p>
     *
     * @author wang
     * @date 2018/11/12
     **/
    @Data
    public class ClassTaskWriteDTO implements Serializable {
        
        private static final long serialVersionUID = -5720405607273123914L;
    
        private Long taskTemplateId;
        /**
         * 发布者id
         */
        private String publisherId;
        /**
         * 发布者名称
         */
        private String publisherName;
        /**
         * 关系
         */
        private String relation;
        /**
         * 班级id
         */
        private String classId;
        /**
         * 班级名称
         */
        private String className;
        /**
         * 学校id
         */
        private String schoolId;
        /**
         * 用户id
         */
        private String userId;
        /**
         * 用户类型
         */
        private Integer roleType;
        /**
         * 任务类型
         */
        private Integer type;
        /**
         * 任务标签
         */
        private String tags;
        /**
         * 标题
         */
        private String title;
        /**
         * 任务介绍
         */
        private String introduction;
        /**
         * 任务内容
         */
        private String content;
        /**
         * 点评
         */
        private String remarkContent;
        /**
         * 任务来源
         */
        private Integer origin;
        /**
         * 连续任务总次数
         */
        private Integer totalCount;
        /**
         * 连续任务总天数
         */
        private Integer totalDay;
        /**
         * 任务参与人数
         */
        private Integer participateCount;
        /**
         * 任务状态 0：进行中，1:已完成 2：已结束 3未开始
         */
        private Integer state;
        /**
         * 统一内容类型
         */
        private Integer contentType;
        private Integer visibility;
        /**
         * 任务开始时间
         */
        private Long startTime;
        /**
         * 任务结束时间
         */
        private Long endTime;
        /**
         * 打卡截止时间
         */
        private String submitEndTime;
    }

可以看到，是使用构造函数实现了转换过程。下面进行改造，使用mapStruct进行转换。

## 使用mapStruct进行修改 ##

### 添加pom文件依赖 ###

<properties>
        <java.version>1.8</java.version>
        <mapstruct.version>1.3.1.Final</mapstruct.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    <dependency>
         <groupId>org.mapstruct</groupId>
         <artifactId>mapstruct</artifactId>
         <version>${mapstruct.version}</version>
    </dependency>
    <dependency>
        <groupId>org.mapstruct</groupId>
        <artifactId>mapstruct-processor</artifactId>
        <version>${mapstruct.version}</version>
    </dependency>

### 添加代码 ###

MyTransform.java，实现不同类型之间的转换

import org.springframework.stereotype.Component;
    
    import java.sql.Timestamp;
    
    @Component
    public class MyTransform {
        
        public Timestamp longToTimestamp(Long t) {
        
            if (t != null) {
        
                return new Timestamp(t);
            }
            return null;
        }
    
        public Long timestampToLong(Timestamp timestamp) {
        
            if (timestamp != null) {
        
                return timestamp.getTime();
            }
            return null;
        }
    }

添加映射类  
MyMapper.java

import org.mapstruct.Mapper;
    
    import java.sql.Timestamp;
    
    @Mapper(
    		// 在spring中使用，可以被Autowared
            componentModel = "spring",
            // 在生成的impl类中，添加import
            imports = Timestamp.class,
            // 使用转换类（转换类需要添加@Commponet）
            uses = {
        MyTransform.class}
    )
    public interface MyMapper {
        
        ClassTaskPO classTaskWriteDTOToClassTaskPO(ClassTaskWriteDTO classTaskWriteDTO);
    
        ClassTaskWriteDTO classTaskPOToClassTaskWriteDTO(ClassTaskPO classTaskPO);
    }

在你ApplicationRunner中进行测试  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dhbmdqaWU1NTQw_size_16_color_FFFFFF_t_70 1]

## 自定生成的impl代码 ##

import java.sql.Timestamp;
    import javax.annotation.Generated;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Component;
    
    @Generated(
        value = "org.mapstruct.ap.MappingProcessor",
        date = "2020-04-04T14:51:17+0800",
        comments = "version: 1.3.1.Final, compiler: javac, environment: Java 1.8.0_111 (Oracle Corporation)"
    )
    @Component
    public class MyMapperImpl implements MyMapper {
        
    
        @Autowired
        private MyTransform myTransform;
    
        @Override
        public ClassTaskPO classTaskWriteDTOToClassTaskPO(ClassTaskWriteDTO classTaskWriteDTO) {
        
            if ( classTaskWriteDTO == null ) {
        
                return null;
            }
    
            ClassTaskPO classTaskPO = new ClassTaskPO();
    
            classTaskPO.setPublisherId( classTaskWriteDTO.getPublisherId() );
            classTaskPO.setPublisherName( classTaskWriteDTO.getPublisherName() );
            classTaskPO.setRelation( classTaskWriteDTO.getRelation() );
            classTaskPO.setClassId( classTaskWriteDTO.getClassId() );
            classTaskPO.setClassName( classTaskWriteDTO.getClassName() );
            classTaskPO.setSchoolId( classTaskWriteDTO.getSchoolId() );
            classTaskPO.setUserId( classTaskWriteDTO.getUserId() );
            classTaskPO.setRoleType( classTaskWriteDTO.getRoleType() );
            classTaskPO.setType( classTaskWriteDTO.getType() );
            classTaskPO.setTags( classTaskWriteDTO.getTags() );
            classTaskPO.setTitle( classTaskWriteDTO.getTitle() );
            classTaskPO.setIntroduction( classTaskWriteDTO.getIntroduction() );
            classTaskPO.setContent( classTaskWriteDTO.getContent() );
            classTaskPO.setRemarkContent( classTaskWriteDTO.getRemarkContent() );
            classTaskPO.setOrigin( classTaskWriteDTO.getOrigin() );
            classTaskPO.setTotalCount( classTaskWriteDTO.getTotalCount() );
            classTaskPO.setTotalDay( classTaskWriteDTO.getTotalDay() );
            classTaskPO.setStartTime( myTransform.longToTimestamp( classTaskWriteDTO.getStartTime() ) );
            classTaskPO.setEndTime( myTransform.longToTimestamp( classTaskWriteDTO.getEndTime() ) );
            classTaskPO.setSubmitEndTime( classTaskWriteDTO.getSubmitEndTime() );
            classTaskPO.setState( classTaskWriteDTO.getState() );
            classTaskPO.setContentType( classTaskWriteDTO.getContentType() );
            classTaskPO.setVisibility( classTaskWriteDTO.getVisibility() );
    
            return classTaskPO;
        }
    
        @Override
        public ClassTaskWriteDTO classTaskPOToClassTaskWriteDTO(ClassTaskPO classTaskPO) {
        
            if ( classTaskPO == null ) {
        
                return null;
            }
    
            ClassTaskWriteDTO classTaskWriteDTO = new ClassTaskWriteDTO();
    
            classTaskWriteDTO.setPublisherId( classTaskPO.getPublisherId() );
            classTaskWriteDTO.setPublisherName( classTaskPO.getPublisherName() );
            classTaskWriteDTO.setRelation( classTaskPO.getRelation() );
            classTaskWriteDTO.setClassId( classTaskPO.getClassId() );
            classTaskWriteDTO.setClassName( classTaskPO.getClassName() );
            classTaskWriteDTO.setSchoolId( classTaskPO.getSchoolId() );
            classTaskWriteDTO.setUserId( classTaskPO.getUserId() );
            classTaskWriteDTO.setRoleType( classTaskPO.getRoleType() );
            classTaskWriteDTO.setType( classTaskPO.getType() );
            classTaskWriteDTO.setTags( classTaskPO.getTags() );
            classTaskWriteDTO.setTitle( classTaskPO.getTitle() );
            classTaskWriteDTO.setIntroduction( classTaskPO.getIntroduction() );
            classTaskWriteDTO.setContent( classTaskPO.getContent() );
            classTaskWriteDTO.setRemarkContent( classTaskPO.getRemarkContent() );
            classTaskWriteDTO.setOrigin( classTaskPO.getOrigin() );
            classTaskWriteDTO.setTotalCount( classTaskPO.getTotalCount() );
            classTaskWriteDTO.setTotalDay( classTaskPO.getTotalDay() );
            classTaskWriteDTO.setState( classTaskPO.getState() );
            classTaskWriteDTO.setContentType( classTaskPO.getContentType() );
            classTaskWriteDTO.setVisibility( classTaskPO.getVisibility() );
            classTaskWriteDTO.setStartTime( myTransform.timestampToLong( classTaskPO.getStartTime() ) );
            classTaskWriteDTO.setEndTime( myTransform.timestampToLong( classTaskPO.getEndTime() ) );
            classTaskWriteDTO.setSubmitEndTime( classTaskPO.getSubmitEndTime() );
    
            return classTaskWriteDTO;
        }
    }

不用自己去写每个属性，只需要写一下mapper，如果需要的话，写一个通用的transform即可

# 评价 #

*  不用再去一个个属性的去写，以免丢失
 *  可以自己定义属性变化
 *  可以在spring中使用mapStruct

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