为什么要使用springMVC?
很多应用程序的问题在于处理业务数据和显示业务数据的视图的对象之间存在紧密耦合。通常,更新业务对象的命令都是从视图本身发起的,使视图对任何业务对象更改都有高度敏感性。而且,当多个视图依赖于同一个业务对象时是没有灵活性的。
Spring Web MVC是一种基于Java的实现了Web MVC设计模式的请求驱动类型的轻量级Web框架,即使用了MVC架构模式的思想,将web层进行职责解耦,基于请求驱动指的就是使用请求-响应模型,框架的目的就是帮助我们简化开发,Spring Web MVC也是要简化我们日常Web开发的。
springMVC优势
1、清晰的角色划分:前端控制器(DispatcherServlet)、请求到处理器映射(HandlerMapping)、处理器适配器(HandlerAdapter)、视图解析器(ViewResolver)、处理器或页面控制器(Controller)、验证器( Validator)、命令对象(Command 请求参数绑定到的对象就叫命令对象)、表单对象(Form Object 提供给表单展示和提交到的对象就叫表单对象)。
2、分工明确,而且扩展点相当灵活,可以很容易扩展,虽然几乎不需要;
3、由于命令对象就是一个POJO,无需继承框架特定API,可以使用命令对象直接作为业务对象;
4、和Spring 其他框架无缝集成,是其它Web框架所不具备的;
5、可适配,通过HandlerAdapter可以支持任意的类作为处理器;
6、可定制性,HandlerMapping、ViewResolver等能够非常简单的定制;
7、功能强大的数据验证、格式化、绑定机制;
8、利用Spring提供的Mock对象能够非常简单的进行Web层单元测试;
9、本地化、主题的解析的支持,使我们更容易进行国际化和主题的切换。
10、强大的JSP标签库,使JSP编写更容易。
………………还有比如RESTful风格的支持、简单的文件上传、约定大于配置的契约式编程支持、基于注解的零配置支持等等。
架构图
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name></display-name>
<filter>
<filter-name>characterFilter</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>characterFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- 加载springMVC的配置文件 -->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
使用xml文件配置
classpath下的springmvc.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:mvc="http://www.springframework.org/schema/mvc"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- 配置映射处理器 BeanNameUrlHandlerMapping 默认-->
<bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"></bean>
<bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="mappings">
<props>
<prop key="/index.do">helloController</prop>
<prop key="/qwe.do">helloController</prop>
</props>
</property>
</bean>
<bean id="helloController" name="/hello.do" class="cn.bdqn.controller.HelloController"></bean>
<!-- 配置处理器适配器 默认-->
<bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"></bean>
<!-- 视图解析器 InternalResourceViewResolver -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<!-- 前缀 -->
<property name="prefix" value="/jsp/"></property>
<!-- 后缀 -->
<property name="suffix" value=".jsp"></property>
</bean>
</beans>
cn.bdqn.controller.HelloController.java
package cn.bdqn.controller;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;
public class HelloController implements Controller{
//返回一个视图
public ModelAndView handleRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
ModelAndView mv = new ModelAndView();
mv.addObject("mesg", "教育改变生活"); // application.setAtr...
mv.setViewName("hello");
return mv;
}
}
hello.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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>
</head>
<body>
<div>${mesg }</div>
</body>
</html>
使用注解配置
classpath下的spring-mvc.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:mvc="http://www.springframework.org/schema/mvc"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<context:component-scan base-package="cn.bdqn"></context:component-scan>
<!-- 注解一键配置 -->
<mvc:annotation-driven></mvc:annotation-driven>
<!-- 视图解析器 InternalResourceViewResolver -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<!-- 前缀 -->
<property name="prefix" value="/jsp/"></property>
<!-- 后缀 -->
<property name="suffix" value=".jsp"></property>
</bean>
</beans>
cn.bdqn.pojo.User
package cn.bdqn.pojo;
public class User {
private Integer age; //年龄
private String uname; //姓名
private String location; //地区
private String sex; //性别
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public String getUname() {
return uname;
}
public void setUname(String uname) {
this.uname = uname;
}
public String getLocation() {
return location;
}
public void setLocation(String location) {
this.location = location;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
@Override
public String toString() {
return "User [age=" + age + ", uname=" + uname + ", location="
+ location + ", sex=" + sex + "]";
}
}
form文件夹下的form1.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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>
</head>
<body>
<form action="${pageContext.request.contextPath}/form/rePojo.do" method="post">
姓名:<input name="uname"/><br/>
年龄:<input name="age" /><Br/>
地址:<select name="location">
<option>北京</option>
<option>合肥</option>
</select><br/>
性别:<input type="radio" name="sex" value="男"/>男
<input type="radio" name="sex" value="女"/>女<br/>
<input type="submit" value="提交"/>
</form>
</body>
</html>
cn.bdqn.controller.FormController.java
package cn.bdqn.controller;
import java.util.Map;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import cn.bdqn.pojo.User;
@Controller
@Scope("prototype")
@RequestMapping("/form")
public class FormController {
@RequestMapping(value="/rePojo.do")
public String rePojo(User user,Model model){ //从页面获取user参数 , 添加Model参数
model.addAttribute(user); //使用此方法将参数传入页面
System.out.println(user);
return "index"; //发送到index.jsp页面
}
}
index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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>
</head>
<body>
姓名----${user.uname}<br/>
年龄----${user.age}<br/>
地区----${user.location}<br/>
性别----${user.sex}<br/>
</body>
</html>
转载于:https://www.cnblogs.com/wxbblogs/p/7263734.html