Java对象属性拷贝工具

超、凢脫俗 2022-12-23 00:49 468阅读 0赞

### Java对象属性拷贝 ###

*  1. 常用工具对比
 *  2. 对比结果分析
 *  3. 集合对象拷贝
 *  4. 对比代码实现

# 1. 常用工具对比 #

常见对象属性拷贝工具  
1.Spring BeanUtils：效率其次  
2.Cglib BeanCopier：效率最高  
3.Apache BeanUtils：效率低,原因Apache BeanUtils力求做的完美，做了很多校验，兼容，日志打印等导致性能下降。  
4.Apache PropertyUtils：效率低

# 2. 对比结果分析 #

对比结果:仅供参考，当然耗时因素很多，机器配置环境等

<table> 
 <thead> 
  <tr> 
   <th>工具类</th> 
   <th>100次消耗时间</th> 
   <th>1000次消耗时间</th> 
   <th>10000次消耗时间</th> 
   <th>100000次消耗时间</th> 
   <th>1000000次消耗时间</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>Spring BeanUtils</td> 
   <td>307</td> 
   <td>14</td> 
   <td>37</td> 
   <td>165</td> 
   <td>1518</td> 
  </tr> 
  <tr> 
   <td>Cglib BeanCopier</td> 
   <td>32</td> 
   <td>3</td> 
   <td>10</td> 
   <td>27</td> 
   <td>80</td> 
  </tr> 
  <tr> 
   <td>Apache BeanUtils</td> 
   <td>28</td> 
   <td>37</td> 
   <td>184</td> 
   <td>767</td> 
   <td>7076</td> 
  </tr> 
  <tr> 
   <td>Apache PropertyUtils</td> 
   <td>2</td> 
   <td>16</td> 
   <td>101</td> 
   <td>857</td> 
   <td>8693</td> 
  </tr> 
 </tbody> 
</table>

# 3. 集合对象拷贝 #

BeanUtils使用instantiateClass初始化对象注意：  
必须保证初始化类必须有public默认无参数构造器，注意初始化内部类时，内部类必须是静态的，否则报错！

import cn.hutool.core.collection.CollectionUtil;
    import com.google.common.collect.Lists;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.beans.BeanUtils;
    import org.springframework.beans.BeansException;
    
    import java.util.List;
    
    /** * 对象属性拷贝 * * @author zrj * @since 2021/7/29 **/
    @Slf4j
    public class BeanUtil { 
        /** * 对象属性拷贝 * 将源对象的属性拷贝到目标对象 * * @param source 源对象 * @param target 目标对象 */
        public static void copyProperties(Object source, Object target) { 
            try { 
                BeanUtils.copyProperties(source, target);
            } catch (BeansException e) { 
                log.error("BeanUtil property copy failed :BeansException", e);
            } catch (Exception e) { 
                log.error("BeanUtil property copy failed:Exception", e);
            }
        }
    
        /** * @param input 输入集合 * @param clzz 输出集合类型 * @param <E> 输入集合类型 * @param <T> 输出集合类型 * @return 返回集合 */
        public static <E, T> List<T> convertList2List(List<E> input, Class<T> clzz) { 
            List<T> output = Lists.newArrayList();
            if (CollectionUtil.isEmpty(input)) { 
                return output;
            }
    
            input.forEach(source -> { 
                T target = BeanUtils.instantiateClass(clzz);
                BeanUtils.copyProperties(source, target);
                output.add(target);
            });
            return output;
        }
    }

# 4. 对比代码实现 #

/** * 对象属性拷贝工具 * 1、Spring BeanUtils：效率其次 * 2、Cglib BeanCopier：效率最高 * 3、Apache BeanUtils：效率低,原因Apache BeanUtils力求做的完美，做了很多校验，兼容，日志打印等导致性能下降。 * 4、Apache PropertyUtils：效率低 * 5、Dozer * 使用场景：DO,DTO,VO,PO,BO等场景装换的时候通过对象属性拷贝提高开发效率，简化代码， * 但是同时也带来了隐藏拷贝了那些属性，没有直接转换更为直接，按需使用吧 * * @author zrj * @version 1.0 * @since 2020/8/18 **/
    public class MapperTest { 
        public static void main(String[] args) throws InvocationTargetException, IllegalAccessException, NoSuchMethodException { 
            PersonDO personDO = new PersonDO();
    
            personDO.setName( "jerry" );
            personDO.setAge( 26 );
            personDO.setBirthday( new Date() );
            personDO.setId( 1 );
    
            MapperTest mapperTest = new MapperTest();
    
            System.out.println( "------mappingBySpringBeanUtils-------" );
            mapperTest.mappingBySpringBeanUtils( personDO, 100 );
            mapperTest.mappingBySpringBeanUtils( personDO, 1000 );
            mapperTest.mappingBySpringBeanUtils( personDO, 10000 );
            mapperTest.mappingBySpringBeanUtils( personDO, 100000 );
            mapperTest.mappingBySpringBeanUtils( personDO, 1000000 );
    
            System.out.println( "------mappingByCglibBeanCopier-------" );
            mapperTest.mappingByCglibBeanCopier( personDO, 100 );
            mapperTest.mappingByCglibBeanCopier( personDO, 1000 );
            mapperTest.mappingByCglibBeanCopier( personDO, 10000 );
            mapperTest.mappingByCglibBeanCopier( personDO, 100000 );
            mapperTest.mappingByCglibBeanCopier( personDO, 1000000 );
    
            System.out.println( "------mappingByApachePropertyUtils-------" );
            mapperTest.mappingByApachePropertyUtils( personDO, 100 );
            mapperTest.mappingByApachePropertyUtils( personDO, 1000 );
            mapperTest.mappingByApachePropertyUtils( personDO, 10000 );
            mapperTest.mappingByApachePropertyUtils( personDO, 100000 );
            mapperTest.mappingByApachePropertyUtils( personDO, 1000000 );
    
            System.out.println( "------mappingByApacheBeanUtils-------" );
            mapperTest.mappingByApacheBeanUtils( personDO, 100 );
            mapperTest.mappingByApacheBeanUtils( personDO, 1000 );
            mapperTest.mappingByApacheBeanUtils( personDO, 10000 );
            mapperTest.mappingByApacheBeanUtils( personDO, 100000 );
            mapperTest.mappingByApacheBeanUtils( personDO, 1000000 );
        }
    
        /** * Spring BeanUtils进行属性拷贝 */
        public void mappingBySpringBeanUtils(PersonDO personDO, int times) { 
            StopWatch stopwatch = new StopWatch();
            stopwatch.start();
    
            for (int i = 0; i < times; i++) { 
                PersonDTO personDTO = new PersonDTO();
                org.springframework.beans.BeanUtils.copyProperties( personDO, personDTO );
            }
    
            stopwatch.stop();
            System.out.println( "mappingBySpringBeanUtils cost " + times + " :" + stopwatch.getTotalTimeMillis() );
        }
    
        /** * Cglib BeanCopier进行属性拷贝 */
        private void mappingByCglibBeanCopier(PersonDO personDO, int times) { 
            StopWatch stopwatch = new StopWatch();
    
            stopwatch.start();
    
            for (int i = 0; i < times; i++) { 
                PersonDTO personDTO = new PersonDTO();
                BeanCopier copier = BeanCopier.create( PersonDO.class, PersonDTO.class, false );
                copier.copy( personDO, personDTO, null );
            }
    
            stopwatch.stop();
    
            System.out.println( "mappingByCglibBeanCopier cost " + times + " :" + stopwatch.getTotalTimeMillis() );
        }
    
        /** * Apache BeanUtils进行属性拷贝 */
        private void mappingByApacheBeanUtils(PersonDO personDO, int times)
                throws InvocationTargetException, IllegalAccessException { 
            StopWatch stopwatch = new StopWatch();
            stopwatch.start();
            for (int i = 0; i < times; i++) { 
                PersonDTO personDTO = new PersonDTO();
                BeanUtils.copyProperties( personDTO, personDO );
            }
            stopwatch.stop();
            System.out.println( "mappingByApacheBeanUtils cost " + times + " :" + stopwatch.getTotalTimeMillis() );
        }
    
        /** * Apache PropertyUtils进行属性拷贝 * 无人问津 */
        private void mappingByApachePropertyUtils(PersonDO personDO, int times)
                throws InvocationTargetException, IllegalAccessException, NoSuchMethodException { 
            StopWatch stopwatch = new StopWatch();
            stopwatch.start();
            for (int i = 0; i < times; i++) { 
                PersonDTO personDTO = new PersonDTO();
                PropertyUtils.copyProperties( personDTO, personDO );
            }
            stopwatch.stop();
            System.out.println( "mappingByApachePropertyUtils cost " + times + " :" + stopwatch.getTotalTimeMillis() );
        }
    }

/** * @author zrj * @version 1.0 * @since 2020/8/18 **/
    @Data
    @NoArgsConstructor
    @AllArgsConstructor
    public class PersonDO { 
        private Integer id;
        private String name;
        private Integer age;
        private Date birthday;
    }
    
    /** * @author zrj * @version 1.0 * @since 2020/8/18 **/
    @Data
    @NoArgsConstructor
    @AllArgsConstructor
    public class PersonDTO { 
        private String name;
        private Integer age;
        private Date birthday;
    }