SpringBoot中的MapStruct使用-CFANZ编程社区

目的:MapStruct可以实现对象之间的转换

一、引入依赖

<!--lombok-->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
</dependency>
<!--mapstruct-->
<dependency>
    <groupId>org.mapstruct</groupId>
    <artifactId>mapstruct</artifactId>
    <version>1.5.2.Final</version>
</dependency>
<dependency>
    <groupId>org.mapstruct</groupId>
    <artifactId>mapstruct-processor</artifactId>
    <version>1.5.2.Final</version>
</dependency>

二、创建两个实体类

import lombok.*;
 
/**
 * @author qinxun
 * @date 2023-06-05
 * @Descripion: 人实体类
 */
@Getter
@Setter
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class Person {
 
    private Long id;
 
    private String name;
 
    private Integer age;
 
}

import lombok.*;
 
/**
 * @author qinxun
 * @date 2023-06-05
 * @Descripion: 人的dto类
 */
@Getter
@Setter
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class PersonDto {
 
    private Long id;
 
    private String name;
 
    private Integer age;
 
}

三、创建MapStruct对象转换接口

import com.example.quartzdemo.bean.Person;
import com.example.quartzdemo.dto.PersonDto;
import org.mapstruct.Mapper;
import org.mapstruct.factory.Mappers;
 
import java.util.List;
 
/**
 * @author qinxun
 * @date 2023-06-05
 * @Descripion: 人的对象mapstruct转换类
 */
@Mapper
public interface PersonConverter {
 
    // 使用工厂方法获取对象实例
    PersonConverter INSTANCE = Mappers.getMapper(PersonConverter.class);
 
    PersonDto personToPersonDto(Person person);
 
    Person personDtoToPerson(PersonDto personDto);
 
    List<PersonDto> personToPersonDto(List<Person> personList);
 
    List<Person> personDtoToPerson(List<PersonDto> personDtoList);
 
}

四、测试

import com.example.quartzdemo.bean.Person;
import com.example.quartzdemo.convert.PersonConverter;
import com.example.quartzdemo.dto.PersonDto;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
 
import java.util.ArrayList;
import java.util.List;
 
@SpringBootTest
class QuartzDemoApplicationTests {
 
    /**
     * person转PersonDto
     */
    @Test
    void personToPersonDto() {
        Person person = new Person(1L, "张三", 25);
        PersonDto personDto = PersonConverter.INSTANCE.personToPersonDto(person);
        // 输出PersonDto(id=1, name=张三, age=25)
        System.out.println(personDto);
    }
 
    /**
     * personDto转Person
     */
    @Test
    void personDtoToPerson() {
        PersonDto personDto = new PersonDto(2L, "李四", 26);
        Person person = PersonConverter.INSTANCE.personDtoToPerson(personDto);
        // 输出Person(id=2, name=李四, age=26)
        System.out.println(person);
    }
 
    /**
     * personList转PersonDtoList
     */
    @Test
    void personListToPersonDtoList() {
        List<Person> personList = new ArrayList<>();
        personList.add(new Person(1L, "张三", 25));
        personList.add(new Person(2L, "李四", 26));
        List<PersonDto> personDtoList = PersonConverter.INSTANCE.personToPersonDto(personList);
        // 输出[PersonDto(id=1, name=张三, age=25), PersonDto(id=2, name=李四, age=26)]
        System.out.println(personDtoList);
    }
 
    /**
     * PersonDtoList转personList
     */
    @Test
    void prsonDtoListToPersonList() {
        List<PersonDto> personDtoList = new ArrayList<>();
        personDtoList.add(new PersonDto(1L, "张三", 25));
        personDtoList.add(new PersonDto(2L, "李四", 26));
        List<Person> personList = PersonConverter.INSTANCE.personDtoToPerson(personDtoList);
        // 输出[Person(id=1, name=张三, age=25), Person(id=2, name=李四, age=26)]
        System.out.println(personList);
    }
 
}

五、如果遇到两个实体类属性名不相同的情况，我们需要对转换器接口进行处理

import java.io.Serializable;
 
/**
 * @author qinxun
 * @date 2023-06-05
 * @Descripion: 人实体类
 */
@Getter
@Setter
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class Person implements Serializable {
 
    private Long id;
 
    private String name;
 
    private Integer age;
 
    private String address;
    
 
}

import lombok.*;
 
/**
 * @author qinxun
 * @date 2023-06-05
 * @Descripion: 人的dto类
 */
@Getter
@Setter
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class PersonDto {
 
    private Long id;
 
    private String name;
 
    private Integer age;
 
    private String addr;
 
}

两个实体中的address和addr代表的都是地址，但是表现形式不一样。这种情况我们需要对抓获接口进行配置

import com.example.quartzdemo.bean.Person;
import com.example.quartzdemo.dto.PersonDto;
import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.Mappings;
import org.mapstruct.factory.Mappers;
 
import java.util.List;
 
/**
 * @author qinxun
 * @date 2023-06-05
 * @Descripion: 人的对象mapstruct转换类
 */
@Mapper
public interface PersonConverter {
 
    // 使用工厂方法获取对象实例
    PersonConverter INSTANCE = Mappers.getMapper(PersonConverter.class);
 
    // source:需要转换的属性 target:转换后的属性
    @Mappings({
            @Mapping(source = "address", target = "addr")
    })
    PersonDto personToPersonDto(Person person);
 
    @Mappings({
            @Mapping(source = "addr", target = "address")
    })
    Person personDtoToPerson(PersonDto personDto);
 
    @Mappings({
            @Mapping(source = "address", target = "addr")
    })
    List<PersonDto> personToPersonDto(List<Person> personList);
 
    @Mappings({
            @Mapping(source = "addr", target = "address")
    })
    List<Person> personDtoToPerson(List<PersonDto> personDtoList);
 
}

测试

import com.example.quartzdemo.bean.Person;
import com.example.quartzdemo.convert.PersonConverter;
import com.example.quartzdemo.dto.PersonDto;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
 
import java.util.ArrayList;
import java.util.List;
 
@SpringBootTest
class QuartzDemoApplicationTests {
 
    /**
     * person转PersonDto
     */
    @Test
    void personToPersonDto() {
        Person person = new Person(1L, "张三", 25, "广州");
        PersonDto personDto = PersonConverter.INSTANCE.personToPersonDto(person);
        // 输出PersonDto(id=1, name=张三, age=25, addr=广州)
        System.out.println(personDto);
    }
 
    /**
     * personDto转Person
     */
    @Test
    void personDtoToPerson() {
        PersonDto personDto = new PersonDto(2L, "李四", 26, "广州");
        Person person = PersonConverter.INSTANCE.personDtoToPerson(personDto);
        // 输出Person(id=2, name=李四, age=26, address=广州)
        System.out.println(person);
    }
 
    /**
     * personList转PersonDtoList
     */
    @Test
    void personListToPersonDtoList() {
        List<Person> personList = new ArrayList<>();
        personList.add(new Person(1L, "张三", 25, "广州"));
        personList.add(new Person(2L, "李四", 26, "广州"));
        List<PersonDto> personDtoList = PersonConverter.INSTANCE.personToPersonDto(personList);
        // 输出[PersonDto(id=1, name=张三, age=25, addr=广州), PersonDto(id=2, name=李四, age=26, addr=广州)]
        System.out.println(personDtoList);
    }
 
    /**
     * PersonDtoList转personList
     */
    @Test
    void prsonDtoListToPersonList() {
        List<PersonDto> personDtoList = new ArrayList<>();
        personDtoList.add(new PersonDto(1L, "张三", 25, "广州"));
        personDtoList.add(new PersonDto(2L, "李四", 26, "广州"));
        List<Person> personList = PersonConverter.INSTANCE.personDtoToPerson(personDtoList);
        // 输出[Person(id=1, name=张三, age=25, address=广州), Person(id=2, name=李四, age=26, address=广州)]
        System.out.println(personList);
    }
 
}

六、自定义转换对于某些类型，没有办法通过代码生成器来进行处理，就需要自定义方法来进行转换。

import java.io.Serializable;
 
/**
 * @author qinxun
 * @date 2023-06-05
 * @Descripion: 人实体类
 */
@Getter
@Setter
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class Person implements Serializable {
 
    private Long id;
 
    private String name;
 
    private Integer age;
 
    private String address;
 
    private SubPerson subPerson;
 
 
}
 
@Getter
@Setter
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class SubPerson {
 
    private Integer deleted;
 
    private String name;
 
}

import lombok.*;
 
/**
 * @author qinxun
 * @date 2023-06-05
 * @Descripion: 人的dto类
 */
@Getter
@Setter
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class PersonDto {
 
    private Long id;
 
    private String name;
 
    private Integer age;
 
    private String addr;
 
    private SubPersonDto subPersonDto;
}
 
@Getter
@Setter
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class SubPersonDto {
 
    private Boolean result;
 
    private String name;
 
}

我们需要在转换接口中添加自定义的转换方法

import com.example.quartzdemo.bean.Person;
import com.example.quartzdemo.bean.SubPerson;
import com.example.quartzdemo.dto.PersonDto;
import com.example.quartzdemo.dto.SubPersonDto;
import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.Mappings;
import org.mapstruct.factory.Mappers;
 
import java.util.List;
 
/**
 * @author qinxun
 * @date 2023-06-05
 * @Descripion: 人的对象mapstruct转换类
 */
@Mapper
public interface PersonConverter {
 
    // 使用工厂方法获取对象实例
    PersonConverter INSTANCE = Mappers.getMapper(PersonConverter.class);
 
    // source:需要转换的属性 target:转换后的属性
    @Mappings({
            @Mapping(source = "address", target = "addr"),
            @Mapping(source = "subPerson", target = "subPersonDto")
    })
    PersonDto personToPersonDto(Person person);
 
    @Mappings({
            @Mapping(source = "addr", target = "address"),
            @Mapping(source = "subPersonDto", target = "subPerson")
    })
    Person personDtoToPerson(PersonDto personDto);
 
    @Mappings({
            @Mapping(source = "address", target = "addr"),
            @Mapping(source = "subPerson", target = "subPersonDto")
    })
    List<PersonDto> personToPersonDto(List<Person> personList);
 
    @Mappings({
            @Mapping(source = "addr", target = "address"),
            @Mapping(source = "subPersonDto", target = "subPerson")
    })
    List<Person> personDtoToPerson(List<PersonDto> personDtoList);
 
    /**
     * 属性的自定义转换
     */
    default SubPersonDto subPersonToSubPersonDto(SubPerson subPerson) {
        if (subPerson == null) {
            return null;
        }
        SubPersonDto subPersonDto = new SubPersonDto();
        subPersonDto.setResult(!subPerson.getDeleted().equals(0));
        subPersonDto.setName(subPerson.getName());
        return subPersonDto;
    }
 
    /**
     * 属性的自定义转换
     */
    default SubPerson subPersonDtoToSubPerson(SubPersonDto subPersonDto) {
        if (subPersonDto == null) {
            return null;
        }
        SubPerson subPerson = new SubPerson();
        subPerson.setDeleted(subPersonDto.getResult() ? 1 : 0);
        subPerson.setName(subPersonDto.getName());
        return subPerson;
    }
}

测试

import com.example.quartzdemo.bean.Person;
import com.example.quartzdemo.bean.SubPerson;
import com.example.quartzdemo.convert.PersonConverter;
import com.example.quartzdemo.dto.PersonDto;
import com.example.quartzdemo.dto.SubPersonDto;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
 
import java.util.ArrayList;
import java.util.List;
 
@SpringBootTest
class QuartzDemoApplicationTests {
 
    /**
     * person转PersonDto
     */
    @Test
    void personToPersonDto() {
        SubPerson subPerson = new SubPerson(0, "zhangsan");
        Person person = new Person(1L, "张三", 25, "广州", subPerson);
        PersonDto personDto = PersonConverter.INSTANCE.personToPersonDto(person);
        // 输出PersonDto(id=1, name=张三, age=25, addr=广州, subPersonDto=SubPersonDto(result=false, name=zhangsan))
        System.out.println(personDto);
    }
 
    /**
     * personDto转Person
     */
    @Test
    void personDtoToPerson() {
        SubPersonDto subPersonDto = new SubPersonDto(false, "lisi");
        PersonDto personDto = new PersonDto(2L, "李四", 26, "广州", subPersonDto);
        Person person = PersonConverter.INSTANCE.personDtoToPerson(personDto);
        // 输出Person(id=2, name=李四, age=26, address=广州, subPerson=SubPerson(deleted=0, name=lisi))
        System.out.println(person);
    }
 
    /**
     * personList转PersonDtoList
     */
    @Test
    void personListToPersonDtoList() {
        List<Person> personList = new ArrayList<>();
        personList.add(new Person(1L, "张三", 25, "广州", new SubPerson(0, "zhangsan")));
        personList.add(new Person(2L, "李四", 26, "广州", new SubPerson(1, "lisi")));
        List<PersonDto> personDtoList = PersonConverter.INSTANCE.personToPersonDto(personList);
        // 输出[PersonDto(id=1, name=张三, age=25, addr=广州, subPersonDto=SubPersonDto(result=false, name=zhangsan)), PersonDto(id=2, name=李四, age=26, addr=广州, subPersonDto=SubPersonDto(result=true, name=lisi))]
        System.out.println(personDtoList);
    }
 
    /**
     * PersonDtoList转personList
     */
    @Test
    void prsonDtoListToPersonList() {
        List<PersonDto> personDtoList = new ArrayList<>();
        personDtoList.add(new PersonDto(1L, "张三", 25, "广州", new SubPersonDto(false, "zhangsan")));
        personDtoList.add(new PersonDto(2L, "李四", 26, "广州", new SubPersonDto(true, "lisi")));
        List<Person> personList = PersonConverter.INSTANCE.personDtoToPerson(personDtoList);
        // 输出[Person(id=1, name=张三, age=25, address=广州, subPerson=SubPerson(deleted=0, name=zhangsan)), Person(id=2, name=李四, age=26, address=广州, subPerson=SubPerson(deleted=1, name=lisi))]
        System.out.println(personList);
    }
 
}