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Java使用mapstruct實(shí)現(xiàn)對(duì)象拷貝

更新時(shí)間：2024年12月06日 10:15:28 作者：前行123

MapStruct可以簡化對(duì)象之間的映射,本文就來介紹一下Java使用mapstruct實(shí)現(xiàn)對(duì)象拷貝,文中通過示例代碼介紹的非常詳細(xì),對(duì)大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價(jià)值,需要的朋友們下面隨著小編來一起學(xué)習(xí)學(xué)習(xí)吧

Mapstructs實(shí)現(xiàn)對(duì)象拷貝:

單個(gè)對(duì)象拷貝(默認(rèn)只拷貝屬性名和方法名都相同的值)，當(dāng)屬性名或者屬性類型不同時(shí)可使用@Mapping注解進(jìn)行映射
List拷貝
List嵌套List拷貝

代碼示例

import lombok.AllArgsConstructor;
import lombok.Data;
import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.Mappings;
import org.mapstruct.factory.Mappers;

import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;

/**
 * Mapstructs實(shí)現(xiàn)實(shí)現(xiàn)拷貝：
 *  1、單個(gè)對(duì)象拷貝
 *  2、List拷貝
 *  3、List嵌套拷貝
 *  4、自定義拷貝規(guī)則
 * MapSturct 是一個(gè)生成類型安全， 高性能且無依賴的 JavaBean 映射代碼的注解處理器，編譯后會(huì)生產(chǎn)相應(yīng)代碼，路徑為
 * target/generated-sources/annotations/BeanCopierUtilImpl.java
 */
@Mapper
interface BeanCopierUtil {
    BeanCopierUtil INSTANCE = Mappers.getMapper(BeanCopierUtil.class);

    /**
     * 單個(gè)對(duì)象轉(zhuǎn)化
     * @param userDto
     * @return
     */
    @Mappings({
            @Mapping(target = "userName", source = "user_name")
    })
    UserVo toVo(UserDto userDto);
    /**
     * List集合拷貝,支持嵌套，需要定義UserDto到UserVo的轉(zhuǎn)化
     */
    List<UserVo> toVo(List<UserDto> userList);
}

public class MapstructTest {
    public static void main(String[] args) {
        List<UserDto> userDtoList = Stream.of(
                new UserDto("1","張三",5),
                new UserDto("2","李四",6)
        ).collect(Collectors.toList());
        List<UserVo> result = BeanCopierUtil.INSTANCE.toVo(userDtoList);
        System.out.println(userDtoList);
        System.out.println(result);

    }
}

@Data
@AllArgsConstructor
class UserDto {
    private String id;
    private String user_name;
    private Integer user_age;
}

@Data
class UserVo {
    private String id;
    private String userName;
    private Integer userAge;
}

運(yùn)行結(jié)果

[UserDto(id=1, user_name=張三, user_age=5), UserDto(id=2, user_name=李四, user_age=6)]
[UserVo(id=1, userName=張三, userAge=null), UserVo(id=2, userName=李四, userAge=null)]

Pom.xml引入依賴包

<properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <mapstruct.version>1.5.5.Final</mapstruct.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.16</version>
            <scope>compile</scope>
        </dependency>
        <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>
            <scope>provided</scope>
        </dependency>
    </dependencies>