Spring中SimpleFormController & MultiActionController合并

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

 

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

     < property name = "mappings" >

     < props >

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

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

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

     </ props >

     </ property >

</ bean >

      

 

< bean id = "LoginController" class = "com.app.web.controller.LoginController" abstract = "false" singleton = "true" >

     < property name = "methodNameResolver" >

     < bean class = "org.springframework.web.servlet.mvc.multiaction.PropertiesMethodNameResolver" >

     < property name = "mappings" >

     < 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:url value = "/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 >

              < input type = "submit" value = "Submit" name = "btnLogin" >

              < input type = "reset"  value = "Reset"  name = "btnReset" >

              < input type = "submit" value = "DetailSubmit" name = "btnDetail" onclick = "doSubmit'<c:urlvalue='/servlet/doDetailProcess.htm'/>')">

              </ p >

       </ form