2.还是先来看下两个模型：ActionForward和ActionModel，没什么东西，属性以及相应的getter,setter方法：

/**
* 类说明:转向模型
* @author dennis
*
* */
public class ActionForward {
private String name; //forward的name 
private String viewUrl; //forward的url 
public static final ActionForward SUCCESS=new ActionForward("success");
public static final ActionForward FAIL=new ActionForward("fail");
public ActionForward(String name){
this.name=name;
}
public ActionForward(String name, String viewUrl) {
super();
this.name = name;
this.viewUrl = viewUrl;
}
//...name和viewUrl的getter和setter方法 

} 

    我们看到ActionForward预先封装了SUCCESS和FAIL对象。

public class ActionModel {
private String path; // action的path 

private String className; // action的class 

private Map<String, ActionForward> forwards; // action的forward 

public ActionModel(){}
public ActionModel(String path, String className,
Map<String, ActionForward> forwards) {
super();
this.path = path;
this.className = className;
this.forwards = forwards;
}
//...相应的getter和setter方法 

} 

    3。知道了两个模型是什么样，也应该可以猜到我们的配置文件大概是什么样的了，与struts的配置文件格式类似：

<?xml version="1.0" encoding="UTF-8"?>
<actions>
<action path="/login"
class="com.strutslet.demo.LoginAction">
<forward name="success" url="hello.jsp"/>
<forward name="fail" url="fail.jsp"/>
</action>
</actions>

    path是在应用中将被调用的路径，class指定了调用的哪个action，forward元素指定了转向，比如我们这里如果是success就转向hello.jsp，失败的话转向fail.jsp，这里配置了demo用到的LoginAction。

    4。Dispacher接口，主要是getNextPage方法，此方法负责获得下一个页面将导向哪里，提供给前端控制器转发。

public interface Dispatcher {
public void setServletContext(ServletContext context);
public String getNextPage(HttpServletRequest request,ServletContext context);
} 

    5。原先书中实现了一个WorkFlow的Dispatcher，按照顺序调用action，实现工作流调用。而我们所需要的是根据请求的path调用相应的action，执行action的execute方法返回一个ActionForward，然后得到ActionForward的viewUrl，将此viewUrl提供给前端控制器转发，看看它的getNextPage方法：

public String getNextPage(HttpServletRequest request, ServletContext context) {
setServletContext(context);
Map<String, ActionModel> actions = (Map<String, ActionModel>) context
.getAttribute(Constant.ACTIONS_ATTR); //从ServletContext得到所有action信息 
String reqPath = (String) request.getAttribute(Constant.REQUEST_ATTR);//发起请求的path 
ActionModel actionModel = actions.get(reqPath); //根据path得到相应的action 
String forward_name = "";
ActionForward actionForward;
try {
Class c = Class.forName(actionModel.getClassName()); //每个请求对应一个action实例 

Action action = (Action) c.newInstance();
actionForward = action.execute(request, context); //执行action的execute方法 
forward_name = actionForward.getName();
} catch (Exception e) {
log.error("can not find action "+actionModel.getClassName());
e.printStackTrace();
}
actionForward = actionModel.getForwards().get(forward_name);
if (actionForward == null) {
log.error("can not find page for forward "+forward_name);
return null;
} else
return actionForward.getViewUrl(); //返回ActionForward的viewUrl 
}