解决springboot中@DynamicUpdate注解无效的问题

import ch.qos.logback.core.joran.util.beans.BeanUtil;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.BeanWrapperImpl;
import java.util.HashSet;
import java.util.Set;
/**
 * created by xxx 2018/7/21
 */
public class BeanCopyUtil {
    //source中的非空属性复制到target中
    public static <T> void beanCopy(T source, T target) {
        BeanUtils.copyProperties(source, target, getNullPropertyNames(source));
    }
    //source中的非空属性复制到target中，但是忽略指定的属性，也就是说有些属性是不可修改的（个人业务需要）
    public static <T> void beanCopyWithIngore(T source, T target, String... ignoreProperties) {
        String[] pns = getNullAndIgnorePropertyNames(source, ignoreProperties);
        BeanUtils.copyProperties(source, target, pns);
    }
    public static String[] getNullAndIgnorePropertyNames(Object source, String... ignoreProperties) {
        Set<String> emptyNames = getNullPropertyNameSet(source);
        for (String s : ignoreProperties) {
            emptyNames.add(s);
        }
        String[] result = new String[emptyNames.size()];
        return emptyNames.toArray(result);
    }
    public static String[] getNullPropertyNames(Object source) {
        Set<String> emptyNames = getNullPropertyNameSet(source);
        String[] result = new String[emptyNames.size()];
        return emptyNames.toArray(result);
    }
    public static Set<String> getNullPropertyNameSet(Object source) {
        final BeanWrapper src = new BeanWrapperImpl(source);
        java.beans.PropertyDescriptor[] pds = src.getPropertyDescriptors();
        Set<String> emptyNames = new HashSet<>();
        for (java.beans.PropertyDescriptor pd : pds) {
            Object srcValue = src.getPropertyValue(pd.getName());
            if (srcValue == null) emptyNames.add(pd.getName());
        }
        return emptyNames;
    }
}

    //这里我设置【任务编号】和【创建人】不可修改
    public void copy(Task task) {
        BeanCopyUtil.beanCopyWithIngore(task, this, "taskNum", "createPerson");
    }

    @Transactional
    public Task updateTask(Task task) {
        try {
            if (task.getId() == null) {
                return null;
            }
            Task saveTask = taskRepository.findOne(task.getId());
            saveTask.copy(task);
            return taskRepository.saveAndFlush(task);
        } catch (Exception e) {
            throw new CustomException(SERVER_ERROR, e);
        }
    }