LookupDispatchAction类处理一个form多个submit

ACTION中重定向

@Override
public String list() throws Exception {
????HttpServletRequest request = ServletActionContext.getRequest();
????String loginName = request.getParameter("j_username");
????String password = request.getParameter("j_password");
????HttpSession session = request.getSession();
????session.setAttribute("username", loginName);
????session.setAttribute("password", password);
????????//你要转向的页面的地址.

????String url = new String( ("../j_spring_security_check?j_username="
????????+java.net.URLEncoder.encode(loginName)
????????+"&j_password="+password).getBytes("UTF-8"),"ISO8859_1");


??? //你要转向的页面的地址.
????HttpServletResponse response = ServletActionContext.getResponse();
????response.sendRedirect(url);
??? //重定向后,别忘了返回null值,而不能再返回return????


??? //mapping.findForward("****");??????
??? return null;
????//return SUCCESS;????????????

}

有时在HTML form中需要提供多个提交按钮，这时LookupDispatchAction类就派上用场了。LookupDispatchAction是DispatchAction的子类，用于处理客户端代码中有一个Form含有多个提交按钮的情况。为了使用LookupDispatchAction，首先来编写客户端代码，代码如下：

?

<html:form?action="myaction">
?????
??? <html:submit?property="action">
??????? <bean:message?key="submit.print"?/>
??? </html:submit>
??? <html:submit?property="action">
??????? <bean:message?key="submit.save"?/>
??? </html:submit>
</html:form>

??? 其中submit.print和submit.save是属性文件中的key.action实际上是提交按钮的name属性值。在提交时，会将property和<bean：message key="……" />作为请求参数和参数值传给Struts动作。如save按钮被单击时，请求URL为http://localhost：8080/……/myaction.do？action=save.其中save为submit.save在属性文件中对应的属性值，也就是说submit.save = save.

??? 接下来我们编写一个LookupDispatchAction的子类，代码如下：

?

package?action;
import?org.apache.struts.actions.LookupDispatchAction;
?
??public?class?MyLookupDispatchAction?extends?LookupDispatchAction
??{
??????//??为了方便描述，在这里未使用属性文件，只是直接将key和value的映射添加到Map对象中
??????//??读者可以在getKeyMethodMap方法中从属性文件中读取相应的key-value对
??????//??来添加到Map对象中
??????protected?Map?getKeyMethodMap()
??????{
??????????Map?m?=?new?HashMap();
??????????m.put("submit.print",?"print");
??????????m.put("submit.save",?"save");
??????????return?m;
??????}
??????public?ActionForward?print?(ActionMapping?mapping,?ActionForm?form,
??????????????HttpServletRequest?request,?HttpServletResponse?response)
??????{
??????????//?处理print代码
??????}?
??????public?ActionForward?save(ActionMapping?mapping,?ActionForm?form,
??????????????HttpServletRequest?request,?HttpServletResponse?response)
??????{
??????????//?处理save代码
??????}?
??}

??? 在编写LookupDispatchAction的子类时要注意必须实现getKeyMethodMap方法，在这个方法中需要进行key和Action方法的映射。下面的代码用来配置MyLookupDispatchAction.

?

<action?path="/moresubmit"?type="action.MyLookupDispatchAction"?parameter="action"?/>

??? 其中parameter属性指定了请求URL中由提交按钮生成的请求参数名