Spring_MVC(3)表单页面处理

1.   
2.         // 跳转到用户信息页面   
3.         return "account/profile";   
4.     }   
5. }  

/**
 * 2010-1-26
 */
package org.zlex.spring.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam; 
import org.zlex.spring.domain.Account;
import org.zlex.spring.service.AccountService;

/**
 * 账户信息控制器
 * 
 * @author <a href="mailto:[email protected]">梁栋</a>
 * @version 1.0
 * @since 1.0
 */
@Controller
@RequestMapping(value = "/profile.do")
public class ProfileController {
	@Autowired
	private AccountService accountService;

	/**
	 * 账户信息展示
	 * 
	 * @param id
	 * @param model
	 * @return
	 */
	@RequestMapping(method = RequestMethod.GET)
	public String profile(@RequestParam("id") int id, ModelMap model) {
		Account account = accountService.read(id);
		model.addAttribute("account", account);

		// 跳转到用户信息页面
		return "account/profile";
	}
}

@RequestMapping(value = "/profile.do")为该控制器绑定url（/profile.do）
@RequestMapping(method = RequestMethod.GET)指定为GET请求
model.addAttribute("account", account);绑定账户
return "account/profile";跳转到“/WEB-INF/page/account/porfile.jsp”页面
对应构建这个页面：
porfile.jsp

<fieldset><legend>用户信息</legend>
<ul>
     <li><label>用户名:</label><c:out value="${account.username}" /></li>
</ul>
</fieldset>

<fieldset><legend>用户信息</legend>
<ul>
	<li><label>用户名:</label><c:out value="${account.username}" /></li>
</ul>
</fieldset>

账户信息已经绑定在response的属性上。自然，使用<c:out />标签就可以获得账户信息内容。
访问地址http://localhost:8080/spring/profile.do?id=1，结果如图所示：

接着构建一个登录控制器LoginController
LoginController.java

/**
 * 2010-1-25
 */
 package org.zlex.spring.controller;

 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.ModelMap;
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.zlex.spring.domain.Account;
 import org.zlex.spring.service.AccountService;

 /**
 * 登录控制器
 *
 * @author <a href="mailto:[email protected]">梁栋</a>
 * @version 1.0
 * @since 1.0
 */
 @Controller
 @RequestMapping(value = "/login.do")
 public class LoginController {

     @Autowired
     private AccountService accountService;

     /**
     * 初始化表单
     *
     * @param model
     * @return
     */
     @RequestMapping(method = RequestMethod.GET)
     public String initForm(ModelMap model) {
         Account account = new Account();
         model.addAttribute("account", account);
         // 直接跳转到登录页面
         return "account/login";
    }

     /**
     * 登录
     *
     * @param account
     * @return
     */
     @RequestMapping(method = RequestMethod.POST)
     public String login(@ModelAttribute("account") Account account) {
        Account acc = accountService.read(account.getUsername(), account
                .getPassword());
         if (acc != null) {
             return "redirect:profile.do?id=" + acc.getId();
         } else {
             return "redirect:login.do";
        }
    }
}

/**
 * 2010-1-25
 */
package org.zlex.spring.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.zlex.spring.domain.Account;
import org.zlex.spring.service.AccountService;

/**
 * 登录控制器
 * 
 * @author <a href="mailto:[email protected]">梁栋</a>
 * @version 1.0
 * @since 1.0
 */
@Controller
@RequestMapping(value = "/login.do")
public class LoginController {

	@Autowired
	private AccountService accountService;

	/**
	 * 初始化表单
	 * 
	 * @param model
	 * @return
	 */
	@RequestMapping(method = RequestMethod.GET)
	public String initForm(ModelMap model) {
		Account account = new Account();
		model.addAttribute("account", account);
		// 直接跳转到登录页面
		return "account/login";
	}

	/**
	 * 登录
	 * 
	 * @param account
	 * @return
	 */
	@RequestMapping(method = RequestMethod.POST)
	public String login(@ModelAttribute("account") Account account) {
		Account acc = accountService.read(account.getUsername(), account
				.getPassword());
		if (acc != null) {
			return "redirect:profile.do?id=" + acc.getId();
		} else {
			return "redirect:login.do";
		}
	}
}

分段详述，先说初始化表单：

/**
 * 初始化表单
 *
 * @param model
 * @return
 */
 @RequestMapping(method = RequestMethod.GET)
 public String initForm(ModelMap model) {
     Account account = new Account();
     model.addAttribute("account", account);
     // 直接跳转到登录页面
     return "account/login";
}

	/**
	 * 初始化表单
	 * 
	 * @param model
	 * @return
	 */
	@RequestMapping(method = RequestMethod.GET)
	public String initForm(ModelMap model) {
		Account account = new Account();
		model.addAttribute("account", account);
		// 直接跳转到登录页面
		return "account/login";
	}

@RequestMapping(method = RequestMethod.GET)指定了GET请求方式，这与POST表单提交相对应！
model.addAttribute("account", account);绑定账户对象，也就是这个登录表单对象
return "account/login";指向登录页面
再看登录方法：

/**
 * 登录
 *
 * @param account
 * @return
 */
 @RequestMapping(method = RequestMethod.POST)
 public String login(@ModelAttribute("account") Account account) {
    Account acc = accountService.read(account.getUsername(), account
            .getPassword());
     if (acc != null) {
         return "redirect:profile.do?id=" + acc.getId();
     } else {
         return "redirect:login.do";
    }
}

	/**
	 * 登录
	 * 
	 * @param account
	 * @return
	 */
	@RequestMapping(method = RequestMethod.POST)
	public String login(@ModelAttribute("account") Account account) {
		Account acc = accountService.read(account.getUsername(), account
				.getPassword());
		if (acc != null) {
			return "redirect:profile.do?id=" + acc.getId();
		} else {
			return "redirect:login.do";
		}
	}

@RequestMapping(method = RequestMethod.POST)绑定POST表单提交请求
@ModelAttribute("account") Account account绑定表单对象。
最后，再来看看页面：
login.jsp

<fieldset><legend>登录</legend><form:form commandName="account">
     <form:hidden path="id" />
    <ul>
         <li><form:label path="username">用户名:</form:label><form:input
             path="username" /></li>
         <li><form:label path="password">密码:</form:label><form:password
             path="password" /></li>
        <li>
         <button type="submit">登录</button>
         <button type="reset">重置</button>
        </li>
    </ul>
</form:form></fieldset>

<fieldset><legend>登录</legend><form:form commandName="account">
	<form:hidden path="id" />
	<ul>
		<li><form:label path="username">用户名:</form:label><form:input
			path="username" /></li>
		<li><form:label path="password">密码:</form:label><form:password
			path="password" /></li>
		<li>
		<button type="submit">登录</button>
		<button type="reset">重置</button>
		</li>
	</ul>
</form:form></fieldset>

注意，<form:form commandName="account">必须指明commandName，且与表单初始化、提交方法中的表单对象名称保持一致！
页面目录结构如下图所示：

在页面中，我加入了一部分css效果，这部分代码我就不在这里唠叨了，大家可以看源码！
登录试试，如图：

用户名：snwolf 密码：zlex
如果登录成功，我们就会跳转到之前的账户信息页面！
注解的确减少了代码的开发量，当然，这对于我们理解程序是一种挑战！如果你不知道原有的SpringMVC的流程，很难一开始就能摆弄清楚这些内容！