Spring中SimpleFormController & MultiActionController合并

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Spring中SimpleFormController & MultiActionController合并

关键字: Java Spring

SimpleFormController & MultiActionController

表面看来SimpleFormController用来处理与Form相关的提交，并且无法进行多个提交处理，必须自己判断提交类型。而MultiActionController可以用来处理如同过方法名字区别的不同提交，便于多个相似业务处理集中，但是却无法处理与Form相关的操作，比较遗憾。如果能将二者结合就好了。

下面有两种解决方案：

1> 自己定义MultiDispachController extends SimpleFormController;

这样MultiDispachController已经具备处理Form功能，然后自己定义MethodNameResolver，并且在onSubmit(HttpServletRequest request,

HttpServletResponse response, Object command, BindException error)

函数中通过MethodNameResolver解析函数名字，并通过反射调用对应函数。

优点：可以灵活配置Form

缺点：使用反射，性能有所损失

2> 直接使用MultiActionController实现

通过对MultiActionController源代码观察，发现以下玄机：

在函数派发的时候MultiActionController会调用如下函数：invokeNamedMethod

而此函数中

// 如果调用参数大于=3，并且第三个参数为HttpSession

if (method.getParameterTypes().length >= 3 &&method.getParameterTypes()[2].equals(HttpSession.class) )

{

HttpSession session = request.getSession(false);

if (session == null) {

throw new HttpSessionRequiredException("Pre-existing session required for handler method '" + methodName + "'");

}

params.add(session);

}

// 如果调用参数大于=3，并且第三个参数不是HttpSession，Spring框架默认为一个//Command,并尝试进行Form绑定操作，如下

// If last parameter isn't of HttpSession type, it's a command.

if (method.getParameterTypes().length >= 3 && !method.getParameterTypes()[method.getParameterTypes().length - 1].equals(HttpSession.class))

{

Object command =newCommandObject(method.getParameterTypes()[method.getParameterTypes().length - 1]);

params.add(command);

bind(request, command);

}

所以基于此隐秘的操作我们可以如下实现，下面是一个简单例子

package com.app.domain;

/**

* @author xh94799

· 一个业务实体包含用户名，密码

public class UserInfo {

private String userName;

private String password;

public UserInfo() {}

public String getPassword() {

return password;

}

public void setPassword(String password) {

this.password = password;

}

public String getUserName() {

return userName;

}

public void setUserName(String userName) {

this.userName = userName;

}

/**

· 一个更详细的业务实体

· 包含用户名，地址，ID 但实际上页面只有用户名密码，此类是用来测试绑定的

package com.app.domain;

public class UserDetailInfo {

private String userName;

private String address;

private String custID;

public UserDetailInfo() { super(); // TODO Auto-generated constructor stub }

public String toString() {

// TODO Auto-generated method stub

StringBuffer sb = new StringBuffer();

sb.append("UserName: " + this.userName).append("Add: " + this.address) .append("CustID: " + this.custID);

return sb.toString();

}

public String getAddress() {

return address;

}

public void setAddress(String address) {

this.address = address;

}

public String getCustID() {

return custID;

}

public void setCustID(String custID) {

this.custID = custID;

}

public String getUserName() {

return userName;

}

public void setUserName(String userName) {

this.userName = userName;

}

下面是我们的Controller

package com.app.web.controller;

// 处理登陆相关多个业务，从MultiActionController派生

public class LoginController extends MultiActionController {

private static Logger _logger = LogManager.getLogger(LoginController.class);

public LoginController() throws ApplicationContextException {

_logger.info("log4j constructor ActionController");

}

/**

* Init Login Form jsp

* 处理页面第一次加载显示，根据函数名识别

public ModelAndView loadLoginView(HttpServletRequest request,

HttpServletResponse response) throws ServletException {

_logger.info("log4j loadLoginView init");

return new ModelAndView(ViewConstant.LOGIN_VIEW);

}

/**

· do Login on user submit 处理登陆校验业务

· 注意第三个参数，为一个Form对象

public ModelAndView doLogin(HttpServletRequest req, HttpServletResponse res,

UserInfo cmd ) throws Exception {

// TODO Auto-generated method stub

_logger.info("LoginController doLogin()");

UserInfo info = cmd;

if ( cmd != null )

{

_logger.info("UserName: " + info.getUserName());

_logger.info("Password: " + info.getPassword());

}

return new ModelAndView(ViewConstant.LOGIN_VIEW);

}

/**

· do Login on user submit 处理登陆细节业务，

· 注意第三个参数，为一个Form对象

· 此处真正的Form为UserInfo，这里用作测试

public ModelAndView doDetailProcess(HttpServletRequest req, HttpServletResponse res,

UserDetailInfo cmd ) throws Exception {

_logger.info("LoginController doDetailProcess()");

UserDetailInfo info = cmd;

if( info != null )

{

_logger.info(info.toString());

}

return new ModelAndView(ViewConstant.LOGIN_VIEW);

}

//可以自定义注册绑定

protected void initBinder(ServletRequest arg0, ServletRequestDataBinder arg1) throws Exception {

// TODO Auto-generated method stub

super.initBinder(arg0, arg1);

SimpleDateFormat dateFormat = new SimpleDateFormat(Constant.DATE_FORMAT);

dateFormat.setLenient(false);

binder.registerCustomEditor(Date.class, null, new CustomDateEditor(dateFormat, false));

}

Action配置

<beanid="urlMapping"class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">

<props>

<prop key="/login.htm" >LoginController</prop>

<prop key="/doLogin.htm">LoginController</prop>

<prop key="/doDetailProcess.htm">LoginController</prop>

</props>

</property>

</bean>

<props>

<prop key="/login.htm">loadLoginView</prop>

<prop key="/doLogin.htm">doLogin</prop>

<prop key="/doDetailProcess.htm">doDetailProcess</prop>

</props>

</property>

</bean>

</property>

</bean>

JSP页面

<form name="loginFrm" action=<c:urlvalue="/servlet/doLogin.htm"/>method="post">

<p align="center">Login</p>

<br>

UserName:<input type="text" name="userName">

<br>

Password:<input type="password" name="password">

<br>

<p>

</p>

</form