Java中对象复制 list复制

在实际项目中，我们常常需要把两个相似的对象相互转换，其目的是在对外提供数据时需要将一部分敏感数据（例如：密码、加密 token 等）隐藏起来

多用于DTO VO DO 对象转换

需要用到的jar

<!-- https://mvnrepository.com/artifact/org.modelmapper/modelmapper -->
        <dependency>
            <groupId>org.modelmapper</groupId>
            <artifactId>modelmapper</artifactId>
            <version>2.3.8</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/junit/junit -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

@Data
@AllArgsConstructor
@NoArgsConstructor
public class StudentDTO {
    private Integer id;
    private String name;
    private Integer age;
    private String email;
    //订单号
    private String orderNo;

}

@Data
public class StudentVO {
    private Integer id;
    private String name;
    private Integer age;
    private String email;

}

需求将 DTO 转换成 VO  (对象状态,集合状态)

public class MyServiceImpl {

    public static StudentDTO studentDTO;

    public static List<StudentDTO> dList;

    static {
        studentDTO = new StudentDTO();

        studentDTO.setId(111);
        studentDTO.setName("张三");
        studentDTO.setAge(18);
        studentDTO.setEmail("abe@163.com");
        studentDTO.setOrderNo("2020123567");

        dList = new ArrayList<StudentDTO>();
        StudentDTO s1 = new StudentDTO(222, "lisi", 28, "345@163", "345");
        StudentDTO s2 = new StudentDTO(333, "zhaoliu", 38, "567@163", "567");
        dList.add(s1);
        dList.add(s2);


    }

    /***
     * 方式一 modeMapper 对象状态
     */
    @Test
    public void test() {
        System.out.println(studentDTO);
        ModelMapper modelMapper = new ModelMapper();
        StudentVO student = modelMapper.map(studentDTO, StudentVO.class);
        System.out.println(student.toString());
    }

    /***
     * 方式一 modeMapper list
     */
    @Test
    public void test2() {
        ModelMapper modelMapper = new ModelMapper();
        List<StudentVO> vList = modelMapper.map(dList, new TypeToken<List<StudentDTO>>() {
        }.getType());
        System.out.println(vList);

    }

    /***
     * 方式二 BeanUtils (spring的) 对象状态
     */
    @Test
    public void test3() {
        StudentVO studentVO = new StudentVO();
        BeanUtils.copyProperties(studentDTO,studentVO);
        System.out.println(studentVO);
    }

    /***
     * 方式二 BeanUtils (spring的)  list
     */
    @Test
    public void test4() {
        List<StudentVO> studentVOList = dList.stream().map(t -> {
            StudentVO studentVO = new StudentVO();
            BeanUtils.copyProperties(t, studentVO);
            return studentVO;
        }).collect(Collectors.toList());
        System.out.println(studentVOList);
    }
}