从零到一 新手教程 - JAVA Spring MVC

简单明了的Spring MVC 基础教学. 

该简单工程的功能流程 : 1. 打开一个 jsp 页面输入必要的信息     2.  将输入的信息存储到 obejct 中    3. 将存储在 object 中的信息传输到另一个 jsp页面并显示.  

1. 建立 dynamic Web project, 并创建以下文件, 文件路径如图显示

 

2. 下载 jar 包 并添加

从这个链接下载. 点我.  (我使用的是4.0.4版本的)  复制粘贴到lib文件夹中, 然后选中所有你刚粘贴到lib中的jar, 右键 build path -> add ....

3.  web.xml 代码如下:

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">  <display-name>SpringMVCTutorial</display-name>  <welcome-file-list>    <welcome-file>index.html</welcome-file>    <welcome-file>index.htm</welcome-file>    <welcome-file>index.jsp</welcome-file>    <welcome-file>default.html</welcome-file>    <welcome-file>default.htm</welcome-file>    <welcome-file>default.jsp</welcome-file>  </welcome-file-list>    <servlet>  <servlet-name>spring-dispatcher</servlet-name>  <servlet-class>  org.springframework.web.servlet.DispatcherServlet  </servlet-class>  </servlet>    <servlet-mapping>  <servlet-name>spring-dispatcher</servlet-name>  <url-pattern>/</url-pattern>  </servlet-mapping>  </web-app

解释: 个人理解, 因为即使是spring mvc 但是它还是java web project (servlet等), 所以所有的请求都首先会来到web.xml这个配置文件, 然后根据这个文件来进行接下来的操作, 从以上代码可以看出来, 我们配置了一个servlet 名称为sping-dispatcher.  所以无论什么请求只要来到web.xml,那么都会被映射到spring-dispatcher-servlet.xml中.  

sping-dispatcher.xml  代码如下:

<?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.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/mvchttp://www.springframework.org/schema/mvc/spring-mvc.xsd"><context:component-scan base-package="com.tutorial.studentadmissioncontroller"/><bean id="viewResolver"class="org.springframework.web.servlet.view.InternalResourceViewResolver" ><property name="prefix"><value>/WEB-INF/</value></property><property name="suffix"><value>.jsp</value></property></bean></beans>

解释: 刚才说到所有请求会从web.xml 来到 spring-dispatcher-servlet.xml中, 在这个里面 重要的是 <context>, 和<bean>.

<context:component-scan base-package="...">  这行代码, 告诉spring mvc 我们的controller 类到包含在这个包里面了, 想要对从web.xml里面来的那个请求进行处理,就从这个包里面找好了. 

<bean> ... </bean>这个里面包含的所有东西, 就有一个目的就是 对 从 controller 中返回的请求进行寻找相对应的jsp/html等文件来显示.

Student.java 代码如下:

package com.tutorial.studentadmissioncontroller;import java.util.ArrayList;import java.util.Date;public class Student {private String studentName;private String studentHobby; private Long studentMobile;private Date studentDOB;private ArrayList<String> studentSkills;private Address address;public Address getAddress() {return address;}public void setAddress(Address address) {this.address = address;}public Date getStudentDOB() {return studentDOB;}public void setStudentDOB(Date studentDOB) {this.studentDOB = studentDOB;}public ArrayList<String> getStudentSkills() {return studentSkills;}public void setStudentSkills(ArrayList<String> studentSkills) {this.studentSkills = studentSkills;}public Long getStudentMobile() {return studentMobile;}public void setStudentMobile(Long studentMobile) {this.studentMobile = studentMobile;}public String getStudentName() {return studentName;}public void setStudentName(String studentName) {this.studentName = studentName;}public String getStudenthobby() {return studentHobby;}public void setStudenthobby(String studenthobby) {this.studentHobby = studenthobby;}}

Address.java 代码如下:

package com.tutorial.studentadmissioncontroller;public class Address {private String country;private String city;private String street;private int pincode;public String getCountry() {return country;}public void setCountry(String country) {this.country = country;}public String getCity() {return city;}public void setCity(String city) {this.city = city;}public String getStreet() {return street;}public void setStreet(String street) {this.street = street;}public int getPincode() {return pincode;}public void setPincode(int pincode) {this.pincode = pincode;}}

StudentAdmissionController.java 代码如下

package com.tutorial.studentadmissioncontroller;import org.springframework.stereotype.Controller;import org.springframework.validation.BindingResult;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.bind.annotation.RequestParam;import org.springframework.web.servlet.ModelAndView;@Controllerpublic class StudentAdmissionController {@RequestMapping(value="/admissionForm.html", method = RequestMethod.GET)public ModelAndView getAdmission(){ModelAndView model = new ModelAndView("AdmissionForm");return model;}@RequestMapping(value="/submitAdmissionForm.html", method = RequestMethod.POST)public ModelAndView submitForm( @ModelAttribute("student") Student student, BindingResult result,@RequestParam(value="defaultvalue", defaultValue="this is a defaultvalue")String value){if(result.hasErrors()){ModelAndView model = new ModelAndView("AdmissionForm");System.out.println("There are some errors...");return model;}ModelAndView model = new ModelAndView("AdmissionSuccess");return model;}}

解释:这个类是spring mvc 的核心, annotation 在这儿被使用. 

1. 当我们 运行该项目的时候, 我们首先要使用http://localhost:8080/SpringMVCTutorial/admissionForm.html    来访问AdmisionForm.jsp.  spring mvc framework会从该链接中提取 admissionForm.html然后到controller类中找相应的mapping. 发现 ok, 一个叫getAdmission()的方法匹配上了,那么接下来的动作都是在这个方法中.  进入该方法, 我们定义了一个ModelAndView 并且 传给他一个参数 AdmissionForm 并且 return.  这个return操作, 会把这个AdmissionForm 传递给spring-dispatcher-servlet.xml 中的<bean>,  然后<bean> 将会在  /WEB-INF/中找AdmissionForm.jsp,  最AdmissionForm.jsp被显示.

2. 当我们在AdmissionForm.jsp中填写好信息之后, 点击submit, 这个请求还会进行web.xml -> spring-dispatcher-servlet.xml - > StudentAdmissionController.java    因为在AdmissionForm.jsp中的action的链接为/SpringMVCtutorial/submitAdmissionForm.html    所以这次在StudentAdmissionController.java中寻找的就是submitAdmissionForm.html , 然后你可以对输入的数据进行操作( 对于spring是如何把从AdmissionForm.jsp中输入的信息封装到studnet类和address类的, 可以留言提问. 不在这里赘述).  最终返回到AdmissionSuccess.jsp 

AdmissionForm.jsp 代码如下:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"    pageEncoding="ISO-8859-1"%><!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=ISO-8859-1"><title>AdmissionForm</title></head><body><h1>STUDENT ADMISSION FORM FOR ENGINEERING COURSES</h1><form action="/SpringMVCtutorial/submitAdmissionForm.html" method="POST"><p>student name : <input type="text" name="studentName"/></p><p>student Hobby : <input type="text" name="studentHobby" /></p><p>student studentMobile : <input type="text" name="studentMobile" /></p><p>student studentDOB : <input type="text" name="studentDOB" /></p><p>student studentSkills : <input type="text" name="studentSkills" /></p><p>default value : <input type="text" name="defaultvalue"></p><h3>Student address</h3><p>country <input type="text" name="address.country"/></p><p>city <input type="text" name="address.city"/></p><p>street <input type="text" name="address.street"/></p><p>pin <input type="text" name="address.pincode" /></p><input type="submit" value="Submit"></form></body></html>

AdmissionSuccess.jsp代码如下:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"    pageEncoding="ISO-8859-1"%><!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=ISO-8859-1"><title>Success</title></head><body></h1> <h2>this is the student details : </h2><p> ${student.studentName} </p><p> ${student.studenthobby}</p><p> ${student.studentMobile}</p><p> ${student.studentDOB}</p><p> ${student.studentSkills}</p><h3>the student address</h3><p>${student.address.country}</p><p>${student.address.city}</p><p>${student.address.street}</p><p>${student.address.pincode}</p></body></html>

4. 使用 

http://localhost:8080/SpringMVCTutorial/admissionForm.html

进行测试