第一種情況: 所有爲空值的屬性都不copy
直接上代碼吧~
public class UpdateUtil {
/**
* 所有爲空值的屬性都不copy
*
* @param source
* @param target
*/
public static void copyNullProperties(Object source, Object target) {
BeanUtils.copyProperties(source, target, getNullField(source));
}
/**
* 獲取屬性中爲空的字段
*
* @param target
* @return
*/
private static String[] getNullField(Object target) {
BeanWrapper beanWrapper = new BeanWrapperImpl(target);
PropertyDescriptor[] propertyDescriptors = beanWrapper.getPropertyDescriptors();
Set<String> notNullFieldSet = new HashSet<>();
if (propertyDescriptors.length > 0) {
for (PropertyDescriptor p : propertyDescriptors) {
String name = p.getName();
Object value = beanWrapper.getPropertyValue(name);
if (Objects.isNull(value)) {
notNullFieldSet.add(name);
}
}
}
String[] notNullField = new String[notNullFieldSet.size()];
return notNullFieldSet.toArray(notNullField);
}
public static void main(String[] args) {
TopMenuConfigEntity topMenuConfigEntity1 = new TopMenuConfigEntity();
topMenuConfigEntity1.setWardCode("cat");
topMenuConfigEntity1.setTitle("animal");
TopMenuConfigEntity topMenuConfigEntity2 = new TopMenuConfigEntity();
topMenuConfigEntity2.setWardCode("dog");
UpdateUtil.copyNullProperties(topMenuConfigEntity2,topMenuConfigEntity1);
System.out.println(topMenuConfigEntity1.getTitle());
}
}
執行main 方法後,topMenuConfigEntity1的title還是爲原來的“animal”值,沒有被topMenuConfigEntity2 的空值覆蓋。
第二種情況:
原對象的屬性有值,複製時指定某些字段不復制
調BeanUtils的這個方法
public static void copyProperties(Object source, Object target, String... ignoreProperties) throws BeansException {
copyProperties(source, target, null, ignoreProperties);
}
public static void main(String[] args) {
TopMenuConfigEntity topMenuConfigEntity1 = new TopMenuConfigEntity();
topMenuConfigEntity1.setWardCode("cat");
topMenuConfigEntity1.setTitle("animal");
topMenuConfigEntity1.setCreateTime(new Date());
TopMenuConfigEntity topMenuConfigEntity2 = new TopMenuConfigEntity();
String[] ignoreArray = new String[]{"title","createTime"};
BeanUtils.copyProperties(topMenuConfigEntity2,topMenuConfigEntity1,ignoreArray);
System.out.println("title : "+topMenuConfigEntity2.getTitle() +";createTime :" + topMenuConfigEntity2.getCreateTime());
}
topMenuConfigEntity2的title 和createTime爲null,沒有複製