将 source 的属性复制给 target
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.BeanWrapperImpl;
import java.util.HashSet;
import java.util.Set;
public class BeanUtil {
public static String[] getNullPropertyNames(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());
}
String[] result = new String[emptyNames.size()];
return emptyNames.toArray(result);
}
}
BeanUtils.copyProperties(source, target, BeanUtil.getNullPropertyNames(source));