/**
* 处理下子模型的嵌套mapping动作
*/
private static void doBeanMapping(BeanMappingParam param, BeanMappingField beanField, BatchObjectHolder holder) {
// 定义valueContext
ValueProcessContext valueContext = new ValueProcessContext(param, param.getConfig(), beanField, holder,
param.getCustomValueContext());
// 检查一下targetClass是否有设置,针对bean对象有效
// 如果目标对象是map,需要客户端强制设定targetClass
GetExecutor getExecutor = beanField.getGetExecutor();
if (getExecutor == null && StringUtils.isNotEmpty(beanField.getSrcField().getName())) {// 可能存在为空