编写RequestUtils，利用BeanUtils封装请求参数的处理（赋值与自动类型转换）过程...

 将request中的所有参数设置到entityClass类型的对象上

public class RequestUtil {

/**
* 将request中的所有参数设置到entityClass类型的对象上
* @param entityClass
* @param request
* @return
*/
public static Object copyParam(Class entityClass,HttpServletRequest request){

try {
Object entity = entityClass.newInstance();

//把请求中的参数取出
Map allParams = request.getParameterMap();
Set entries = allParams.entrySet();
for (Iterator iterator = entries.iterator(); iterator.hasNext();) {
Map.Entry entry = (Map.Entry) iterator.next();
String name = (String)entry.getKey();
String[] value = (String[])entry.getValue();

if(value != null){
if(value.length == 1){
BeanUtils.copyProperty(entity, name, value[0]);
}else{
BeanUtils.copyProperty(entity, name, value);
}
}
}
return entity;
} catch (Exception e) {
e.printStackTrace();
}

return null;
}
}

 在到servlet页面上就可以直接写 

Article a = (Article)RequestUtil.copyParam(Article.class, request);