struts2是MVC框架,其中org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter过滤器是前端控制器
使用Action类模拟二级分发控制器来实现减少对s2标签的依赖,这样的话对模板原型的破坏会比较小,实现方式如下
public class _Base extends ActionSupport{
private String action ="";
private String message ="";
public void setAction(String action){this.action=action;}
public String getAction(){return this.action;}
public void setMessage(String message){this.message=message;}
public String getMessage(return this.message);
public String dispatcher(){
String _action = this.getAction();
String _invokeAction ="doIndex";
if(StringUtils.isBlank(_action)){
}else{
_invokeAction = _action;
}
String _result = SUCCESS;
try{
Object obj = org.apache.commons.beanutils.MethodUtils.invokeMethod(this, _action, new Object[]{});
if(obj!=null){
_result = obj.toString();
}
}catch(Exception e){
this.setMessage(e.getMessage());
}
return _result;
}
public String doIndex(){
return SUCCESS;
}
}
public class Login extends _Base{
private String username="";
private String password="";
public void setUsername(String username){this.username=username;}
public String getUsername(){return this.username;}
public void setPassword(String password){this.password=password;}
public String getPassword(){return this.password;}
public String doLogin(){
try{
//invoke service
return "home";
}catch(Exception e){
}
retrun INPUT;
}
public String doLogout(){
//clear session
return SUCCESS;
}
}
struts.xml
<action name="Login" class="Login" method="dispatcher">
<result name="success" type="freemarker">/WEB-INF/content/Login.ftl</result>
<result name="input" type="freemarker">/WEB-INF/content/Login.ftl</result>
<result name="home" type="redirectAction">Home</result>
</action>
Login.ftl
<html><head><title></title></head><body>
<form>
<input type="hidden" name="action" value="doLogin"/><!--此隐藏域作为分发器的分发标志-->
<input type="text" name="username" value="${username}"/>
<input type="text" name="password" value="${password}"/>
<input type="submit" value="登陆"/>
</form>
</body></html>
登出的链接则产生 Login.do?action=doLogout
此思想来源于php的mvc实现,在php中实现MVC的框架一般都是有一个前端控制器如
index.php,通过传参调用不同的控制器和action,如
index.php?ctrl=Login&action=defaultView
index.php?ctrl=Login&action=doLogin
index.php?ctrl=Login&action=doLogout
