Java对象转换的方案分享

@Data
public class UserDO {
  private Long id;
  private String name;
  private Integer gender;
  private String passWord;
  private Date gmtCreate;
  private Date gmtModified;
}

@Data
public class UserDTO {
  private Long id;
  private String name;
  private Integer gender;
}

private static void simpleBeanCopy() {
    BeanCopier beanCopier = BeanCopier.create(UserDO.class, UserDTO.class, false);
    UserDO userDO = new UserDO();
    userDO.setId(1L);
    userDO.setName("aihe");
    userDO.setGmtCreate(new Date());
    userDO.setGender(0);
    userDO.setPassword("xxxxxx");
    UserDTO userDTO = new UserDTO();
    beanCopier.copy(userDO, userDTO,null);
    Assert.assertEquals("名称未成功拷贝",userDTO.getName(),"aihe");
    Assert.assertEquals("Id未成功拷贝", 1L, (long)userDTO.getId());
    Assert.assertEquals("性别未成功拷贝", Integer.valueOf(0),userDTO.getGender());
  }

package me.aihe.daka;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import net.sf.cglib.beans.BeanCopier;

public class BeanCopyUtils {

    
    private static Map<Class<?>, Map<Class<?>, BeanCopier>> beanCopierMap = new ConcurrentHashMap<>();
    
    public static <S,T> void copy(S sourceBean,T targetBean){
        @SuppressWarnings("unchecked")
        Class<S> sourceClass = (Class<S>) sourceBean.getClass();
        @SuppressWarnings("unchecked")
        Class<T> targetClass = (Class<T>) targetBean.getClass();

        BeanCopier beanCopier = getBeanCopier(sourceClass,targetClass);
        beanCopier.copy(sourceBean,targetBean,null);
    }
    
    public static <S,T> T convert(S sourceBean,Class<T> targetClass){
        try {
            assert sourceBean!=null;
            T targetBean = targetClass.newInstance();
            copy(sourceBean,targetBean);
            return targetBean;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
    private static <S,T> BeanCopier getBeanCopier(Class<S> sourceClass, Class<T> targetClass ){
        Map<Class<?>,BeanCopier> map = beanCopierMap.get(sourceClass);
        if(map == null || map.isEmpty()){
            BeanCopier newBeanCopier = BeanCopier.create(sourceClass, targetClass, false);
            Map<Class<?>,BeanCopier> newMap = new ConcurrentHashMap<>();
            newMap.put(targetClass,newBeanCopier);
            beanCopierMap.put(sourceClass,newMap);
            return newBeanCopier;
        }
        BeanCopier beanCopier = map.get(targetClass);
        if(beanCopier == null){
            BeanCopier newBeanCopier = BeanCopier.create(sourceClass, targetClass, false);
            map.put(targetClass,newBeanCopier);

            return newBeanCopier;
        }
        return beanCopier;
    }
}

UserDO userDO = new UserDO();
    userDO.setId(1L);
    userDO.setName("aihe");
    userDO.setGmtCreate(new Date());
    userDO.setGender(0);
    userDO.setPassword("xxxxxx");
    UserDTO userDTO = new UserDTO();
    BeanCopyUtils.copy(userDO, userDTO);
    Assert.assertEquals("名称未成功拷贝",userDTO.getName(),"aihe");
    Assert.assertEquals("Id未成功拷贝", 1L, (long)userDTO.getId());
    Assert.assertEquals("性别未成功拷贝", Integer.valueOf(0),userDTO.getGender());

<properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <org.mapstruct.version>1.5.2.Final</org.mapstruct.version>
        <org.projectlombok.version>1.18.20</org.projectlombok.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.mapstruct</groupId>
            <artifactId>mapstruct</artifactId>
            <version>${org.mapstruct.version}</version>
        </dependency>

        <dependency>
            <groupId>org.mapstruct</groupId>
            <artifactId>mapstruct-processor</artifactId>
            <version>${org.mapstruct.version}</version>
            <!-- IntelliJ does not pick up the processor if it is not in the dependencies.
             There is already an open issue for IntelliJ see https://youtrack.jetbrains.com/issue/idea-150621
            -->
            <scope>provided</scope>
        </dependency>
       
         <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${org.projectlombok.version}</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>

@Mapper
public interface UserDTOMapper {

    UserDTOMapper MAPPER = Mappers.getMapper( UserDTOMapper.class );
    //@Mapping( source = "test", target = "testing" )
    //@Mapping( source = "test1", target = "testing2" )
    UserDTO toTarget( UserDO s );
}

public static void main( String[] args ) {
        //simpleDemo();
        UserDO userDO = new UserDO();
        userDO.setId(1L);
        userDO.setName("aihe");
        userDO.setGmtCreate(new Date());
        userDO.setGender(0);
        userDO.setPassword("xxxxxx");
        UserDTO userDTO = UserDTOMapper.MAPPER.toTarget(userDO);
        Assert.assertEquals("名称未成功拷贝",userDTO.getName(),"aihe");
        Assert.assertEquals("Id未成功拷贝", 1L, (long)userDTO.getId());
        Assert.assertEquals("性别未成功拷贝", Integer.valueOf(0),userDTO.getGender());
    }

@Mapping(target = "userNick1", source = "userNick")
@Mapping(target = "createTime", source = "createTime", dateFormat = "yyyy-MM-dd")
@Mapping(target = "age", source = "age", numberFormat = "#0.00")
@Mapping(target = "id", ignore = true)
@Mapping(target = "userVerified", defaultValue = "defaultValue-2")
UserDTO toTarget( UserDO s );

import java.util.Date;
import com.alibaba.fastjson.JSON;
import org.junit.Before;
import org.junit.Test;

public class BenchDemoTest{

  
  private UserDO userDO;

  
  private final static int count = 1000000;
  @Before
  public void before() {
    userDO = new UserDO();
    userDO.setId(1L);
    userDO.setName("aihe");
    userDO.setGmtCreate(new Date());
    userDO.setGender(0);
    userDO.setPassword("xxxxxx");
  }
  @Test
  public void mapstruct() {
    long startTime = System.currentTimeMillis();
    for (int i = 1; i <=count; i++) {
      UserDTO userDTO = UserDTOMapper.MAPPER.toTarget(userDO);
    }
    System.out.println("mapstruct time" + (System.currentTimeMillis() - startTime));
  }
  @Test
  public void beanCopier() {
    long startTime = System.currentTimeMillis();
    for (int i = 1; i <= count; i++) {
      UserDTO targetBean = new UserDTO();
      BeanCopyUtils.copy(userDO, targetBean);
    }
    System.out.println("beanCopier time" + (System.currentTimeMillis() - startTime));
  }
  @Test
  public void springBeanUtils(){
    long startTime = System.currentTimeMillis();
    for (int i = 1; i <=count; i++) {
      UserDTO userDTO = new UserDTO();
      org.springframework.beans.BeanUtils.copyProperties(userDO, userDTO);
    }
    System.out.println("springBeanUtils time" + (System.currentTimeMillis() - startTime));
  }
  @Test
  public void fastjson() {
    long startTime = System.currentTimeMillis();
    for (int i = 1; i <= count; i++) {
      JSON.parseObject(JSON.toJSONString(userDO), UserDTO.class);
    }
    System.out.println("fastjson time" + (System.currentTimeMillis() - startTime));
  }
}