자바 대상 복사, 원본 대상 source 대상 target

import org.springframework.beans.BeansException;
import org.springframework.beans.FatalBeanException;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;

import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.List;

import static org.springframework.beans.BeanUtils.getPropertyDescriptor;
import static org.springframework.beans.BeanUtils.getPropertyDescriptors;

/**
 * Java    ,   source     target
 */
public class BeanUtils {


    /**
     *     
     *         
     * @param source              
     * @param target               
     * @param ignoreProperties     n    
     */
    private static void copyProperties(Object source, Object target, String... ignoreProperties)
            throws BeansException {

        Assert.notNull(source, "Source must not be null");
        Assert.notNull(target, "Target must not be null");

        Class> actualEditable = target.getClass();
        PropertyDescriptor[] targetPds = getPropertyDescriptors(actualEditable);
        List ignoreList = (ignoreProperties != null) ? Arrays.asList(ignoreProperties) : null;

        for (PropertyDescriptor targetPd : targetPds) {
            Method writeMethod = targetPd.getWriteMethod();
            if (writeMethod != null && (ignoreProperties == null || (!ignoreList.contains(targetPd.getName())))) {
                PropertyDescriptor sourcePd = getPropertyDescriptor(source.getClass(), targetPd.getName());
                if (sourcePd != null) {
                    Method readMethod = sourcePd.getReadMethod();
                    if (readMethod != null &&
                            ClassUtils.isAssignable(writeMethod.getParameterTypes()[0], readMethod.getReturnType())) {
                        try {
                            if (!Modifier.isPublic(readMethod.getDeclaringClass().getModifiers())) {
                                readMethod.setAccessible(true);
                            }
                            Object value = readMethod.invoke(source);
                            if(value != null){
                                if (!Modifier.isPublic(writeMethod.getDeclaringClass().getModifiers())) {
                                    writeMethod.setAccessible(true);
                                }
                                writeMethod.invoke(target, value);
                            }
                        }
                        catch (Throwable ex) {
                            throw new FatalBeanException(
                                    "Could not copy property '" + targetPd.getName() + "' from source to target", ex);
                        }
                    }
                }
            }
        }
    }
}