springmvc的工作原理是:1、浏览器发送请求给DispatcherServlet;2、根据请求找到对应的Controller;3、返回ModelAndView;4、找到对应的视图对象View并渲染;5、返回到浏览器。
SpringMVC工作原理:
(推荐学习:java入门程序)
1、浏览器发送指定的请求都会交给DispatcherServlet,他会委托其他模块进行真正的业务和数据处理;
2、DispatcherServlet会查找到HandleMapping,根据浏览器的请求找到对应的Controller,并将请求交给目标Controller;
3、目标Controller处理完业务后,返回一个ModelAndView给DispatcherServlet;
4、DispatcherServlet通过ViewResolver视图解析器找到对应的视图对象View;
4、视图对象View负责渲染,并返回到浏览器。
(视频教程推荐:java教程)
下面我们来看一下代码实例:
web.xml
<?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_2_5.xsd version=2.5> <display-name>springmvc</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> <!-- spring入口 --> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!-- 项目启动时,就加载并实例化 --> <load-on-startup>1</load-on-startup> </servlet> <!-- 拦截所有不包括jsp的请求 --> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>*.do</url-pattern> </servlet-mapping> </web-app>
springmvc-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:aop=http://www.springframework.org/schema/aop xmlns:context=http://www.springframework.org/schema/context xmlns:tx=http://www.springframework.org/schema/tx xmlns:mvc=http://www.springframework.org/schema/mvc xsi:schemaLocation=http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd> <!-- springmvc注解驱动 --> <mvc:annotation-driven></mvc:annotation-driven> <!-- 开启注解扫描 --> <context:component-scan base-package=cn.itcast.controller></context:component-scan> <!-- 配置试图解析器 prefix:指定试图所在目录 suffix:指定视图的后缀名 例如:prifex=/WEB-INF/jsp/,suffix=.jsp,当viewname=test时,跳转到/WEB-INF/jsp/test.jsp页面 --> <bean class=org.springframework.web.servlet.view.InternalResourceViewResolver> <property name=prefix value=/WEB-INF/jsp/></property> <property name=suffix value=.jsp></property> </bean> </beans>
UserControll类
@Controller @RequestMapping(user) public class UserController { @RequestMapping(findAllUsers) public ModelAndView findAllUsers() { ModelAndView mv = new ModelAndView(); ArrayList<User> users = new ArrayList<User>(); for (int i = 0; i < 5; i++) { User user = new User(); user.setUsername(zs + i); user.setAge(20 + i); user.setIncome(16000.0+i*100); user.setIsMarry(false); user.setHobby(new String[] { 篮球+i, 足球+i }); users.add(user); } mv.addObject(users, users); mv.setViewName(users); return mv; } }
实体类
public class User implements Serializable { /** * */ private static final long serialVersionUID = 1L; private String username; private Integer age; private Boolean isMarry; private Double income; private String[] hobby; public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public Boolean getIsMarry() { return isMarry; } public void setIsMarry(Boolean isMarry) { this.isMarry = isMarry; } public Double getIncome() { return income; } public void setIncome(Double income) { this.income = income; } public String[] getHobby() { return hobby; } public void setHobby(String[] hobby) { this.hobby = hobby; } @Override public String toString() { return User [username= + username + , age= + age + , isMarry= + isMarry + , income= + income + , hobby= + Arrays.toString(hobby) + ]; } }
jsp页面
<%@ page language=java contentType=text/html; charset=UTF-8 pageEncoding=UTF-8%> <%@ taglib prefix=c uri=http://java.sun.com/jsp/jstl/core%> <!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>Insert title here</title> <link rel=stylesheet type=text/css href=/css/user.css /> </head> <body> <table id=customers> <tr> <th>用户名</th> <th>年龄</th> <th>收入</th> <th>婚姻状态</th> <th>兴趣爱好</th> </tr> <!-- 遍历后台传递的集合数据 --> <c:forEach items=${users} var=user> <tr> <td>${user.username}</td> <td>${user.age}</td> <td>${user.income}</td> <!-- 判婚姻状态 --> <td><c:choose> <c:when test=${user.isMarry}>已婚</c:when> <c:otherwise>未婚</c:otherwise> </c:choose> </td> <td> <!-- 再次遍历用户爱好 --> <c:forEach items=${user.hobby} var=hobby varStatus=status> ${hobby} <!-- 如果不是最后一个爱好,则加上逗号,否则就不加 --> <c:if test=${!status.last}>,</c:if> </c:forEach> </td> </tr> </c:forEach> </table> </body> </html>
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