代码改变世界

BeanUtils.copyProperties() 处理null参数被复制问题

2021-07-29 14:18  方斌  阅读(834)  评论(0)    收藏  举报

import org.apache.commons.collections.CollectionUtils;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.BeanWrapperImpl;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

import java.util.*;

/**
 * @description:
 * @projectName:({PROJECT_NAME}
 * @see:{PACKAGE_NAME}
 * @author:fb
 * @createTime:2021/7/29 11:29
 * @version:1.0
 */
public class SpringUtil implements ApplicationContextAware {

    /**
     * 当前IOC
     *
     */
    private static ApplicationContext applicationContext;

    /**
     * * 设置当前上下文环境,此方法由spring自动装配
     *
     */
    @Override
    public void setApplicationContext(ApplicationContext arg0)
            throws BeansException {
        applicationContext = arg0;
    }

    /**
     * 从当前IOC获取bean
     *
     * @param id
     * bean的id
     * @return
     *
     */
    public static Object getObject(String id) {
        Object object = null;
        object = applicationContext.getBean(id);
        return object;
    }

    public static String[] getNullPropertyNames (Object source) {
        final BeanWrapper src = new BeanWrapperImpl(source);
        java.beans.PropertyDescriptor[] pds = src.getPropertyDescriptors();

        Set<String> emptyNames = new HashSet<String>();
        for(java.beans.PropertyDescriptor pd : pds) {
            Object srcValue = src.getPropertyValue(pd.getName());
            if (srcValue == null) emptyNames.add(pd.getName());
        }
        String[] result = new String[emptyNames.size()];
        return emptyNames.toArray(result);
    }

    public static void copyPropertiesIgnoreNull(Object src, Object target){
        BeanUtils.copyProperties(src, target, getNullPropertyNames(src));
    }

    /*public static void copyPropertiesIgnoreNull(Object src, Object target, String... ignoreProperties){
        List<String> ignoreList = ignoreProperties != null ? Arrays.asList(ignoreProperties) : new ArrayList<>(2);
        String[] nullName = getNullPropertyNames(src);
        ignoreList.addAll(Arrays.asList(nullName));

        String[] ignoreNameList = new String[ignoreList.size()];
        ignoreList.toArray(ignoreNameList);

        BeanUtils.copyProperties(src, target, ignoreNameList);
    }*/

}

用法


SpringUtil.copyPropertiesIgnoreNull(source, target);