我们在基于Spring框架进行web开发时，通常会有dao层（数据库操作），service层（业务逻辑操作，比如判断是否在redis，memcached等缓存中查找数据，何时调用dao层），web层（接收前端用户的请求，调用service层，向前端响应数据与视图）。其中，Spring框架为service层做了较好的支持，mybatis、hibernate等框架为dao层做了较好的支持，Spring-MVC、Struts2等框架为web层做了较好的支持。通常来说，基于Spring框架开发的web项目有SSM（Spring，Spring-MVC，mybatis）体系，SSH（Spring，Spring-MVC，hibernate）体系等。我在此处通过代码演示下Spring-MVC是如何运行的。我们先看Spring-MVC框架的运行图：
首先，我们要在web项目中添加Spring-MVC的jar包依赖，在此基础上开发项目。本项目案例文件包结构如下所示：
接下来，配置web.xml文件：
<?xml version="1.0" encoding="UTF-8"?>
<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">
<!--注册过滤器,避免中文乱码-->
<filter>
<filter-name>encoding</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>encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!--注册前端控制器-->
<servlet>
<servlet-name>spring-mvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc-config.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>spring-mvc</servlet-name>
<url-pattern>*.html</url-pattern>
</servlet-mapping>
</web-app>
再配置springmvc-config.xml文件：
<?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"
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">
<!--配置页面控制器/处理器,采用注解方式-->
<context:component-scan base-package="com.itszt.controller"></context:component-scan>
<!--寻址与控制器处理的注解支持-->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"></bean>
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"></bean>
<!--配置视图解析器-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
</beans>
后台Java代码如下：
package com.itszt.domain;
/**
* 实体类,狗的名字,颜色
*/
public class Dog {
private String dogname;
private String dogcolor;
public String getDogname() {
return dogname;
}
@Override
public String toString() {
return "Dog{" +
"dogname=‘" + dogname + ‘\‘‘ +
", dogcolor=‘" + dogcolor + ‘\‘‘ +
‘}‘;
}
public void setDogname(String dogname) {
this.dogname = dogname;
}
public String getDogcolor() {
return dogcolor;
}
public void setDogcolor(String dogcolor) {
this.dogcolor = dogcolor;
}
}
----------------------------------------------
package com.itszt.domain;
import java.util.Arrays;
/**
* 实体类,用户的姓名,年龄,爱好,宠物狗
*/
public class User {
private String username;
private Integer userage;
private String[] userhbs;
private Dog dog;
public String getUsername() {
return username;
}
@Override
public String toString() {
return "User{" +
"username=‘" + username + ‘\‘‘ +
", userage=" + userage +
", userhbs=" + Arrays.toString(userhbs) +
", dog=" + dog +
‘}‘;
}
public void setUsername(String username) {
this.username = username;
}
public Integer getUserage() {
return userage;
}
public void setUserage(Integer userage) {
this.userage = userage;
}
public String[] getUserhbs() {
return userhbs;
}
public void setUserhbs(String[] userhbs) {
this.userhbs = userhbs;
}
public Dog getDog() {
return dog;
}
public void setDog(Dog dog) {
this.dog = dog;
}
}
---------------------------------------------------------
package com.itszt.controller;
import com.itszt.domain.User;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
/**
* 控制器
*/
@Controller
@RequestMapping("/orgCenter")
public class OrgController {
@RequestMapping("/add")
public String add(User user, HttpServletRequest request, HttpSession session){
System.out.println("OrgController.add");
System.out.println("接收参数User="+user);
request.setAttribute("user",user);
StringBuffer sbf=new StringBuffer();
for(String s:user.getUserhbs()){
sbf.append(s+",");
}
String userhbs=sbf.toString();
request.setAttribute("userhbs",userhbs.substring(0,userhbs.length()-1));
request.setAttribute("dog",user.getDog());
return "result";
}
}
前端index.jsp页面代码如下：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>演示springmvc实现过程</title>
</head>
<body>
<form action="/orgCenter/add.html" method="post">
<h3>
用户姓名:<input type="text" name="username" value="张三"/>
</h3>
<h3>
用户年龄:<input type="number" name="userage" value="15"/>
</h3>
<h3>
用户爱好:<input type="checkbox" name="userhbs" value="climb"/>爬山
<input type="checkbox" name="userhbs" value="swim"/>游泳
<input type="checkbox" name="userhbs" value="basketball"/>篮球
<input type="checkbox" name="userhbs" value="football"/>足球
</h3>
<h3>
宠物狗:
名字:<input type="text" name="dog.dogname" value="旺旺"/>
毛色:<input type="text" name="dog.dogcolor" value="黄色"/>
</h3>
<h3>
<input type="submit" value="提交">
</h3>
</form>
</body>
</html>
服务器端的OrgController响应页面如下：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>返回结果</title>
</head>
<body>
我是result.jsp页面<br>
返回结果是:<br>
您发来的用户姓名:${user.username}<br>
用户年龄:${user.userage}<br>
用户爱好:${userhbs}<br>
宠物狗:<br>
名字:${dog.dogname}<br>
毛色:${dog.dogcolor}<br>
</body>
</html>
希望对您有所帮助！
