Struts ActionFrom 原理 实现

package com.vili.wems.web.webservice.ma.information;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.util.Enumeration;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.struts.action.ActionForm;

public class FormUtils {

public static void fillForm(HttpServletRequest request,String formFullClassName,String formName){
try {
//1.利用JAVA的反射机制获得当前传进来的BEAN对象
ActionForm form =(ActionForm)Class.forName(formFullClassName).newInstance();
PropertyDescriptor[] properties = Introspector.getBeanInfo(form.getClass()).getPropertyDescriptors();

//2.取得页面中的传递元素
Enumeration formParameters = request.getParameterNames();

//3.遍历元素
while(formParameters.hasMoreElements()){
String parameterName = (String)formParameters.nextElement();

for(PropertyDescriptor property:properties){
String properyName = property.getName();

//4.比较两个对象的名称是否相等,如果相等则填充FORM
if(parameterName.equals(properyName))
{
String propertyValue = request.getParameter(properyName);
BeanUtils.setProperty(form, properyName, propertyValue);
}
}

}

//5.保存填充好的对象
request.getSession().setAttribute(formName, form);
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IntrospectionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

}