废料 Struts2获取request三种方法
复习啊..
struts2里面有三种方法可以获取request,最好使用ServletRequestAware接口通过IOC机制注入Request对象。
- 在Action中获取request方法一：
在Action中的代码：
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Map request = (Map)ActionContext.getContext().get(
"request"
);
List<Task> tasks = taskManager.findAll();
request.put(
"tasks"
, tasks);
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在JSP页面中获取其中的值：
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<
s:iterator
id
=
"task"
value
=
"#request.tasks"
>
<
tr
class
=
"table_header"
>
<
td
><
s:property
value
=
"#task.tname"
/></
td
>
<
td
><
s:property
value
=
"#task.tuid"
/></
td
>
<
td
><
s:property
value
=
"#task.tstartTime"
/></
td
>
<
td
><
s:property
value
=
"#task.tendTime"
/></
td
>
<
td
><
s:property
value
=
"#task.tstate"
/></
td
>
<
td
><
input
type
=
"radio"
id
=
"choose"
name
=
"choose"
onclick
=
"getId(this.value)"
value="<s:property
value
=
'#task.tid'
/>"/></
td
>
</
tr
>
</
s:iterator
>
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--------------------------------------------------------------------------------------------
- 方法二：通过ServletActionContext类来获取，使用struts2经验如果处理get传参是中文，只能使用该方法进行处理乱码问题
Action中代码：
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HttpServletRequest request = ServletActionContext.getRequest();
request.setAttribute(
"username"
,
"zhangsan"
);
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在jsp中获取其中的值
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<
s:property
value
=
"#request.username"
>或者${requestScope.req}
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--------------------------------------------------------------------------------------------
- 方法三：通过ServletRequestAware接口通过IOC机制注入Request对象
Action中的代码：
Action实现ServletRequestAware接口，实现接口中的方法
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private
HttpServletRequest request;
//实现接口中的方法
public
void
setServletRequest(HttpServletRequest request){
this
.request = request;
}
//然后在execute()方法中就可以使用了
public
String execute(){
request.setAttribute(
"username"
,
"zhangsan"
);
request.getSession().getServletContext().getApplication();
//得到Application
}
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该方法必须要实现，而且该方法是自动被调用
这个方法在被调用的过程中，会将创建好的request对象通过参数的方式传递给你，你可以用来赋给你本类中的变量，然后request就可以使用了
注意：setServletRequest()方法一定会再execute()方法被调用前执行
在jsp页面中获取其中的值
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<
s:property
value
=
"#request.task.tname"
/>
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1、浏览器往Action传递参数：
在Action中设置属性，并为属性设置get/set方法。传递参数时按照属性的名字赋值即可。如xxx?name=aa
取值用request.getPrameters("属性名“）;
<span class="kwd">public</span><span class="pln"> </span><span class="kwd">class</span><span class="pln"> </span><span class="typ">UserAction</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span>
<span class="pln"> </span><span class="kwd">private</span><span class="pln"> </span><span class="typ">String</span><span class="pln"> name</span><span class="pun">;</span><span class="pln"> </span>
<span class="pln"> </span><span class="kwd">private</span><span class="pln"> </span><span class="typ">User</span><span class="pln"> user</span><span class="pun">;</span><span class="pln"> </span>
<span class="pln"> </span><span class="kwd">public</span><span class="pln"> </span><span class="typ">String</span><span class="pln"> userAdd</span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span>
<span class="pln"> </span><span class="typ">System</span><span class="pun">.</span><span class="kwd">out</span><span class="pun">.</span><span class="kwd">print</span><span class="pun">(</span><span class="pln">user</span><span class="pun">.</span><span class="pln">getName</span><span class="pun">());</span><span class="pln"> </span>
<span class="pln"> </span><span class="typ">System</span><span class="pun">.</span><span class="kwd">out</span><span class="pun">.</span><span class="kwd">print</span><span class="pun">(</span><span class="pln">name</span><span class="pun">);</span><span class="pln"> </span>
<span class="pln"> </span><span class="kwd">return</span><span class="pln"> </span><span class="str">"success"</span><span class="pun">;</span><span class="pln"> </span>
<span class="pln"> </span><span class="pun">}</span><span class="pln"> </span>
<span class="pln"> </span><span class="kwd">public</span><span class="pln"> </span><span class="typ">String</span><span class="pln"> getName</span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span>
<span class="pln"> </span><span class="kwd">return</span><span class="pln"> name</span><span class="pun">;</span><span class="pln"> </span>
<span class="pln"> </span><span class="pun">}</span><span class="pln"> </span>
<span class="pln"> </span><span class="kwd">public</span><span class="pln"> </span><span class="kwd">void</span><span class="pln"> setName</span><span class="pun">(</span><span class="typ">String</span><span class="pln"> name</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span>
<span class="pln"> </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">name </span><span class="pun">=</span><span class="pln"> name</span><span class="pun">;</span><span class="pln"> </span>
<span class="pln"> </span><span class="pun">}</span><span class="pln"> </span>
<span class="pln"> </span><span class="kwd">public</span><span class="pln"> </span><span class="typ">User</span><span class="pln"> getUser</span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span>
<span class="pln"> </span><span class="kwd">return</span><span class="pln"> user</span><span class="pun">;</span><span class="pln"> </span>
<span class="pln"> </span><span class="pun">}</span><span class="pln"> </span>
<span class="pln"> </span><span class="kwd">public</span><span class="pln"> </span><span class="kwd">void</span><span class="pln"> setUser</span><span class="pun">(</span><span class="typ">User</span><span class="pln"> user</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span>
<span class="pln"> </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">user </span><span class="pun">=</span><span class="pln"> user</span><span class="pun">;</span><span class="pln"> </span>
<span class="pln"> </span><span class="pun">}</span><span class="pln"> </span>
<span class="pun">}</span><span class="pln"> </span>
注：struts2不会使用单例模式，因此每次的请求都是new 一个新对象。
2、Action 往浏览器界面传递参数：
方式有三种：
1）种：直接给Action 属性（有get/set方法）赋值 ，JSP中用
- <s:property value="OGNL表达式"/> 取值，注意返回结果类型为forward
例如：
- <s:property value="name"/>
- <s:property value="user.name"/>
2）种：通过ActionContext传值，在Action中所调用的方法中加入：
<p><span style="font-family: Arial, Helvetica, sans-serif; line-height: 22px; white-space: normal;"><span class="typ">ActionContext</span><span class="pun">.</span><span class="pln">getContext</span><span class="pun">().</span><span class="pln">put</span><span class="pun">(</span></span><span style="font-family: Arial, Helvetica, sans-serif; line-height: 22px; white-space: normal;">"key"</span><span style="font-family: Arial, Helvetica, sans-serif; line-height: 22px; white-space: normal;"><span class="pun">,</span><span class="pln"> </span></span><span style="font-family: Arial, Helvetica, sans-serif; line-height: 22px; white-space: normal;">"value"</span><span style="font-family: Arial, Helvetica, sans-serif; line-height: 22px; white-space: normal;"><span class="pun">);</span><span class="pln"> </span></span></p>
JSP中用
- <s:property value="#key"/>取值
3）种：通过request、session 传值。Action方法中通过取得HttpServletRequest 、HttpSession 和 Map对象设置值，
例如：
<p><span class="typ">ServletActionContext</span><span class="pun">.</span><span class="pln">getRequest</span><span class="pun">().</span><span class="pln">setAttribute</span><span class="pun">(</span><span class="str">"arg0"</span><span class="pun">,</span><span class="pln"> </span><span class="str">"value"</span><span class="pun">);</span><span class="pln"> </span> <span class="typ">ServletActionContext</span><span class="pun">.</span><span class="pln">getRequest</span><span class="pun">().</span><span class="pln">getSession</span><span class="pun">().</span><span class="pln">setAttribute</span><span class="pun">(</span><span class="str">"arg0"</span><span class="pun">,</span><span class="pln"> </span><span class="str">"value"</span><span class="pun">);</span><span class="pln"> </span> <span class="typ">ActionContext</span><span class="pun">.</span><span class="pln">getContext</span><span class="pun">().</span><span class="pln">getSession</span><span class="pun">().</span><span class="pln">put</span><span class="pun">(</span><span class="str">"key"</span><span class="pun">,</span><span class="pln"> </span><span class="str">"value"</span><span class="pun">);</span><span class="pln"> </span></p>
jsp页面通过：
【转自】 http://cailangwei.blog.163.com/blog/static/131458579201287112552485/
在上面的代码中， 在Action实现了一个 ServletRequestAware接口，并且实现了 setServletRequest方法。
如果一个动作类实现了 ServletRequestAware接口， Struts2在调用 execute方法之前，就会先调用setServletRequest方法，并将Request参数传入这个方法。如果想获得 HttpServletResponse、HttpSession和 Cookie等对象，动作类可以分别实现 ServletResponseAware、 SessionAware和CookiesAware等接口。这些接口都在 org.apache.struts2.interceptor包中。
struts2超链接传值： <s:a href="info.action?id=%{#list.id}"> <s:property value="#list.title"/></s:a>