Spring MVC 表單處理例子下面的例子說明瞭如何編寫一個簡單的基於web 的應用程序,它利用了使用Spring 的Web MVC 框架的HTML 表單。
一測試項目搭建
(1)新建Java Web項目,並引入幾個SpringMVC項目所需要的jar包,項目結構和所需要的jar包如下:
①web.xml:
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1"> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>*.html</url-pattern> </servlet-mapping> <filter> <filter-name>characterEncodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>characterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping></web-app>
這裡定義了SpringMVC攔截以.html結尾的url後綴並進行處理
②springmvc-servlet.xml:
<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd"> <context:component-scan base-package="cn.zifangsky.* *.controller" /> <context:annotation-config /> <!-- 激活Bean中定義的註解--> <mvc:annotation-driven /> <bean > <property name="prefix" value="/WEB-INF/pages/" /> <property name="suffix" value=".jsp" /> </bean></beans>
在上面的配置文件中,<context:annotation-config />激活了Bean中定義的一些註解,而<mvc:annotation-driven />則啟動了SpringMVC的一些默認配置。在配置文件的最後則定義了邏輯視圖到實際視圖之間的對應關係,一句話解釋就是:給返回的邏輯視圖加上上面定義的路徑前綴和後綴就是實際視圖的真正路徑了。
二使用SpringMVC處理Form表單
(1)在正式開始之前,先建立一個model和枚舉類:
①實體類User:
package cn.zifangsky.model;import java.time.LocalDate;import org.springframework.format.annotation.DateTimeFormat;public class User { private String name; private String password; private String job; @DateTimeFormat(pattern="yyyy-MM-dd") private LocalDate birthDate; private Gender gender; private String country; private boolean smoking; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getJob() { return job; } public void setJob(String job) { this.job = job; } public LocalDate getBirthDate() { return birthDate; } public void setBirthDate(LocalDate birthDate) { this.birthDate = birthDate; } public Gender getGender() { return gender; } public void setGender(Gender gender) { this.gender = gender; } public String getCountry() { return country; } public void setCountry(String country) { this.country = country; } public boolean isSmoking() { return smoking; } public void setSmoking(boolean smoking) { this.smoking = smoking; } } ②表示“性別”的枚舉類Gender:
package cn.zifangsky.model; public enum Gender { MALE, FEMALE;}下面將依照程序的執行流程來簡單說明SpringMVC的Form表單處理,分別是前台的form表單填寫>controller處理>處理結果視圖頁面
(2)測試項目的首頁與form表單頁面:
①首頁index.jsp:
<% response.sendRedirect("form.html"); %>可以看出,在這裡我們的首頁很簡單,就是重定向到“form.html”,但是通過我們前面在web.xml中的配置,SpringMVC將會對這個請求轉到一個具體的controller中進行處理,當然這裡就是直接轉到form表單頁面。具體的controller裡的處理邏輯下面再說
②form表單頁面userForm.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><%@taglib uri="http://www.springframework.org/tags/form" prefix="mvc"%><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Spring MVC Form Handling</title></head><body> <h2>用戶註冊</h2> <mvc:form modelAttribute="user" action="result.html"> <table> <tr> <td><mvc:label path="name">姓名:</mvc:label></td> <td><mvc:input path="name" /></td> </tr> <tr> <td><mvc:label path="password">密碼:</mvc:label></td> <td><mvc:password path="password" /></td> </tr> <tr> <td><mvc:label path="job">工作:</mvc:label></td> <td><mvc:textarea path="job" /></td> </tr> <tr> <td><mvc:label path="birthDate">生日:</mvc:label></td> <td><mvc:input path="birthDate" /></td> </tr> <tr> <td><mvc:label path="gender">性別:</mvc:label></td> <td><mvc:radiobuttons path="gender" items="${genders}" /></td> </tr> <tr> <td><mvc:label path="country">居住地:</mvc:label></td> <td><mvc:select path="country" items="${countries}" /></td> </tr> <tr> <td><mvc:label path="smoking">吸煙嗎:</mvc:label></td> <td><mvc:checkbox path="smoking" /></td> </tr> <tr> <td colspan="2"><input type="submit" value="Submit" /></td> </tr> </table> </mvc:form></body></html>由於我們把這個頁面放在了WEB-INF目錄下,因此是不能直接通過URL對這個文件進行訪問的,必須前面定義的“form.html”轉到controller處理後顯示這個視圖頁面,這樣做的目的是防止一些私密的頁面在未授權的情況下被其他人隨意訪問。在上面的文件中,需要注意的是:
(3)業務邏輯處理的controller類UserController.java:
package cn.zifangsky.controller; import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.ModelAttribute;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.servlet.ModelAndView;import cn.zifangsky.model.Gender;import cn.zifangsky.model.User;@Controllerpublic class UserController { private static final String[] countries = {"China","Japan","North Korea","United States"}; @RequestMapping(value="/form.html") public ModelAndView user(){ ModelAndView modelAndView = new ModelAndView("userForm"); modelAndView.addObject("user", new User()); modelAndView.addObject("genders",Gender.values()); modelAndView.addObject("countries", countries); return modelAndView; } @RequestMapping(value="/result.html") public ModelAndView processUser(@ModelAttribute(value="user") User u){ ModelAndView modelAndView = new ModelAndView("userResult"); modelAndView.addObject("u",u); return modelAndView; } }可以看出,在上面定義了兩個方法,它們的作用分別是針對“form.html”請求轉到真實的form表單以及對form表單的處理。在對錶單處理時通過@ModelAttribute註解接收了一個User類型的“u”,也就是前面填寫的form表單,後面就是表單的顯示因此不多說
(4)測試:
①表單填寫:
②結果顯示:
userResult.jsp頁面:
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><%@taglib uri="http://www.springframework.org/tags/form" prefix="mvc"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Spring MVC Form Handling</title></head><body> <h2>註冊結果</h2> <table> <tr> <td>姓名:</td> <td>${u.name}</td> </tr> <tr> <td>密碼:</td> <td>${u.password}</td> </tr> <tr> <td>工作:</td> <td>${u.job}</td> </tr> <tr> <td>生日:</td> <td>${u.birthDate}</td> </tr> <tr> <td>性別:</td> <td>${u.gender}</td> </tr> <tr> <td>居住地:</td> <td>${u.country}</td> </tr> <tr> <td>吸煙嗎:</td> <td>${u.smoking}</td> </tr> </table></body></html>以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持武林網。