ognl and token and a little method at the beginning

Store data in ValueStack

The first way to get the value stack ( very troublesome)

ActionContext actionContext = ActionContext . getContext();
Map<String,Object> reqmap = (Map<String, Object>) actionContext.get("request");
ValueStack valueStack = (ValueStack) reqmap.get("struts.valueStack");

the second way

HttpServletRequest request= ServletActionContext.getRequest();
ValueStack valueStack = (ValueStack)request.getAttribute（“struts.valueStack”）;

third way

ActionContext actionContext = ActionContext.getCOntext();
ValueStack valueStack = actionContext.getValueStack();

This second and third is a bit like yesterday's, it seems to be the way to get the context ?

wait i see

Oh no , it's Session , it's all inexplicable to the request

Then take out the quoted name from the request

Store data on the value stack

valueStack.put(new Student( " Little Black " ,20));

This is placed on the top of the stack, and the attribute of the student class is regarded as name ,

Another one that can also be stored is to put it directly outside and use private ,

setValue(String str,Object obj)

Adding a # sign is to store a key-value pair in the ActionContext , the key is name , and the value is pipipi

valueStack.setValue(“#name”,”pipipipi”);

Without the # sign, the first attribute name is overwritten. If there is no such attribute name, an error will be reported.

valuStack.setValue(“name”,”bibibib”);

set(String key ,Object obj)

Encapsulate a hashmap and use the value of the key as the key,

valueStack.set(“stu”,new new Student(“xiaohua”,21);

valueStack.push(new Student(“xiaohua”,22);

I have to see what this set and push are for

This is a JSP page

I didn't want to write, I really don't know what to write

Just barely write

<s:debug></s:debug>

<s:property value=”[0].name”/>

<s:property value=”[1].name”/>

<s:property value=”[2].name”/>

The problem is that I put a lot of useless things in the back (the back is on the top)

Then it starts drawing frames one by one,

1,2,3,4,5，6

These values are always the first

Well, let's see how the implementation works

ActionContext context = ActionContext.getContext();

ValueStack valueStack=context.getValueStack();

Object obj = ValueStack.findValue(“name”);

out.println(obj);

这原理好特么浅啊。。。。。。。

下一项吧

serlvet中的查找顺序

pageContext,request,session,application

Struts中使用el表达式的搜索顺序

request.ValueStack,ActionContext,Session,Applilcation

从值栈找不到，会去actioncontext中查找

没有使用var，每次迭代出来的对象放入值栈的栈顶

      <s:iterator value="stuts" status="st">
           <tr>
              <td><s:property value="#st.count"/></td>
              <td><s:property value="name"/></td>
              <td><s:property value="age"/></td>
           </tr>
         </s:iterator>  
       </table>
 
  <s:iterator value="stuts.{?#this.age>22}" status="st">
           <tr>
              <td><s:property value="#st.count"/></td>
              <td><s:property value="name"/></td>
              <td><s:property value="age"/></td>
           </tr>
         </s:iterator>  
 
 
     <s:iterator value="stuts" var="stu" status="st">
           <tr>
              <td><s:property value="#st.count"/></td>
              <td><s:property value="#stu.name"/></td>
              <td><s:property value="#stu.age"/></td>
           </tr>
         </s:iterator>

<!--

ognl投影：筛选字段

-->

<s:iterator value="stuts.{name}" status="st">

<tr>

</tr>

</s:iterator>

</table>

自己理解吧贼简单看一遍就懂了但是我现在不想看了嘤嘤嘤

哦对这个东西叫令牌，想了半天没想起来

首先在jsp页面上写

<s:token></s:token>

然后再Struts中配置

就是加个拦截器的功效

<interceptor-ref name=”token”></interceptor-ref>

记得把默认加进去

<interceptor-ref name=”defaultStack”></

啊不写了还有个什么界面

不管了

出道题：暂时想的

1：用户登录

（设上用户名密码验证，后台验证）

2：登录后看到一个表

（用ognl看出来）

（这个表就是注册用户表吧）

3：新增用户

（时间格式，后台验证）

（设置回显，设置回显样式）

不过拦截器是干嘛来着，哦对，看有没有Session，

可以用在show界面前面，ok就这样

也可以想一点别的，关于拦截器

写项目的小总结，边写边总结，

那估计会写的更慢了。。。

继承的是ActionSupport，实现的是 ModelDriven接口

怎么记不住呢

验证器怎么写来着。。。

总算被我（在帮助下）找到了原始的文件

验证器源文件：

Web App Libraries 下

xwork-core-2.3.15.3.jar下（dtd约束也在）

com.opensymphony.xwork2下

validator下

validators下

default.xml

给自己挖的两个坑

只用写类名-动作名-validation.xml

就可以了

不过是动作名！！动作名！！

记得还要写返回结果，所以才能看到啊（摊手）

<result name=”input”>/login.jsp</result>

C3P0怎么写又忘了。。。。。。。。。。。。

private static DataSource ds = new ComboPooledDataSource();

public static DataSource getDataSource(){

return ds;

遇到了谜一样的数据库链接失败问题不管了

ognl and token and a little method at the beginning

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