Spring MVC下拉选项(Select)

package com.h3.springmvc;
public class user {

   private string username;
   private string password;
   private string address;
   private boolean receivepaper;
   private string [] favoriteframeworks;   
   private string gender;
   private string favoritenumber;
   private string country;

   public string getusername() {
      return username;
   }
   public void setusername(string username) {
      this.username = username;
   }

   public string getpassword() {
      return password;
   }
   public void setpassword(string password) {
      this.password = password;
   }
   public string getaddress() {
      return address;
   }
   public void setaddress(string address) {
      this.address = address;
   }
   public boolean isreceivepaper() {
      return receivepaper;
   }
   public void setreceivepaper(boolean receivepaper) {
      this.receivepaper = receivepaper;
   }
   public string[] getfavoriteframeworks() {
      return favoriteframeworks;
   }
   public void setfavoriteframeworks(string[] favoriteframeworks) {
      this.favoriteframeworks = favoriteframeworks;
   }
   public string getgender() {
      return gender;
   }
   public void setgender(string gender) {
      this.gender = gender;
   }
   public string getfavoritenumber() {
      return favoritenumber;
   }
   public void setfavoritenumber(string favoritenumber) {
      this.favoritenumber = favoritenumber;
   }
   public string getcountry() {
      return country;
   }
   public void setcountry(string country) {
      this.country = country;
   }
}

usercontroller.java 的代码如下所示 -

package com.h3.springmvc;
import java.util.arraylist;
import java.util.hashmap;
import java.util.list;
import java.util.map;

import org.springframework.stereotype.controller;
import org.springframework.web.bind.annotation.modelattribute;
import org.springframework.web.bind.annotation.requestmapping;
import org.springframework.web.bind.annotation.requestmethod;
import org.springframework.web.servlet.modelandview;
import org.springframework.ui.modelmap;

@controller
public class usercontroller {

   @requestmapping(value = "/user", method = requestmethod.get)
   public modelandview user() {
      user user = new user();      
      user.setfavoriteframeworks((new string []{"spring mvc","struts 2"}));
      user.setgender("m");
      modelandview modelandview = new modelandview("user", "command", user);
      return modelandview;
   }

   @requestmapping(value = "/adduser", method = requestmethod.post)
   public string adduser(@modelattribute("springweb")user user, 
      modelmap model) {
      model.addattribute("username", user.getusername());
      model.addattribute("password", user.getpassword());
      model.addattribute("address", user.getaddress());
      model.addattribute("receivepaper", user.isreceivepaper());
      model.addattribute("favoriteframeworks", user.getfavoriteframeworks());
      model.addattribute("gender", user.getgender());
      model.addattribute("favoritenumber", user.getfavoritenumber());
      model.addattribute("country", user.getcountry());     
      return "userlist";
   }

   @modelattribute("webframeworklist")
   public list<string> getwebframeworklist()
   {
      list<string> webframeworklist = new arraylist<string>();
      webframeworklist.add("spring mvc");
      webframeworklist.add("struts 1");
      webframeworklist.add("struts 2");
      webframeworklist.add("apache wicket");
      return webframeworklist;
   }

   @modelattribute("numberslist")
   public list<string> getnumberslist()
   {
      list<string> numberslist = new arraylist<string>();
      numberslist.add("1");
      numberslist.add("2");
      numberslist.add("3");
      numberslist.add("4");
      return numberslist;
   }

   @modelattribute("countrylist")
   public map<string, string> getcountrylist()
   {
      map<string, string> countrylist = new hashmap<string, string>();
      countrylist.put("us", "united states");
      countrylist.put("ch", "china");
      countrylist.put("sg", "singapore");
      countrylist.put("my", "malaysia");
      return countrylist;
   }
}

这里的第一个服务方法user()，我们已经在modelandview对象中传递了一个名称为“command”的空user对象，因为如果在jsp文件中使用<form:form>标签，spring框架需要一个名称为“command”的对象。所以当调用user()方法时，它返回user.jsp视图。

第二个服务方法adduser()将根据url => dropdown/adduser 上的post方法请求时调用。根据提交的信息准备模型对象。最后从服务方法返回“userlist”视图，这将呈现userlist.jsp视图。

user.jsp 的代码如下所示 -

<%@ page contenttype="text/html; charset=utf-8"%>

<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<html>
<head>
<title>spring mvc表单处理(下拉选择)</title>
</head>
<body>

    <h2>用户信息</h2>
    <form:form method="post" action="/dropdown/adduser">
        <table>
            <tr>
                <td><form:label path="username">用户名：</form:label></td>
                <td><form:input path="username" /></td>
            </tr>
            <tr>
                <td><form:label path="password">密码：</form:label></td>
                <td><form:password path="password" /></td>
            </tr>
            <tr>
                <td><form:label path="address">地址：</form:label></td>
                <td><form:textarea path="address" rows="5" cols="30" /></td>
            </tr>
            <tr>
                <td><form:label path="receivepaper">是否订阅：</form:label></td>
                <td><form:checkbox path="receivepaper" /></td>
            </tr>
            <tr>
                <td><form:label path="favoriteframeworks">喜欢的框架/技术：</form:label></td>
                <td><form:checkboxes items="${webframeworklist}"
                        path="favoriteframeworks" /></td>
            </tr>
            <tr>
                <td><form:label path="gender">性别：</form:label></td>
                <td><form:radiobutton path="gender" value="m" label="男" /> <form:radiobutton
                        path="gender" value="f" label="女" /></td>
            </tr>
            <tr>
                <td><form:label path="favoritenumber">喜欢的数字：</form:label></td>
                <td><form:radiobuttons path="favoritenumber"
                        items="${numberslist}" /></td>
            </tr>
            <tr>
                <td><form:label path="country">所在国家：</form:label></td>
                <td><form:select path="country">
                        <form:option value="none" label="请选择..." />
                        <form:options items="${countrylist}" />
                    </form:select></td>
            </tr>

            <tr>
                <td colspan="2"><input type="submit" value="提交" /></td>
            </tr>
        </table>
    </form:form>
</body>
</html>

这里使用<form:select /> , <form:option /> 和 <form:options />标签来呈现html密码框。例如 -

<form:select path="country">
   <form:option value="none" label="select"/>
   <form:options items="${countrylist}" />
</form:select>

它将呈现以下html内容。

<select id="country" name="country">
   <option value="none">请选择...</option>
   <option value="us">united states</option>
   <option value="ch">china</option>
   <option value="my">malaysia</option>
   <option value="sg">singapore</option>
</select>

userlist.jsp 的代码如下所示 -

<%@ page contenttype="text/html; charset=utf-8"%>
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<html>
<head>
<title>spring mvc表单处理(下拉选择)</title>
</head>
<body>

    <h2>提交用户信息 -</h2>
    <table>
        <tr>
            <td>用户名：</td>
            <td>${username}</td>
        </tr>
        <tr>
            <td>密码：</td>
            <td>${password}</td>
        </tr>
        <tr>
            <td>地址：</td>
            <td>${address}</td>
        </tr>
        <tr>
            <td>是否订阅：</td>
            <td>${receivepaper}</td>
        </tr>
        <tr>
            <td>喜欢的技术/框架：</td>
            <td>
                <%
                    string[] favoriteframeworks = (string[]) request.getattribute("favoriteframeworks");
                    for (string framework : favoriteframeworks) {
                        out.println(framework);
                    }
                %>
            </td>
        </tr>
        <tr>
            <td>性别：</td>
            <td>${(gender=="m"? "男" : "女")}</td>
        </tr>
        <tr>
         <td>喜欢的数字：</td>
         <td>${favoritenumber}</td>
      </tr>  
      <tr>
         <td>国家：</td>
         <td>${country}</td>
      </tr>   
    </table>
</body>
</html>

完成创建源和配置文件后，发布应用程序到tomcat服务器。

现在启动tomcat服务器，现在尝试访问url => http://localhost:8080/dropdown/user ，如果spring web应用程序没有问题，应该看到以下结果：

提交所需信息后，点击提交按钮提交表单。如果spring web应用程序没有问题，应该看到以下结果：