Spring Mvc 学习 （一）入门案例

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Spring Mvc 是什么？

Spring web mvc和Struts2都属于表现层的框架,它是Spring框架的一部分,我们可以从Spring的整体结构中看得出来,如下图：

Spring Mvc 处理流程

先说一下大致的流程
1 首先，用户发送一个请求，请求由前端控制器接受，前端控制器本身不处理请求，他只负责接受与传递，
2 前端控制器将请求传递给对应的处理器，处理器处理此请求，
3 处理器处理请求完成之后，返回给控制器
4 但是呢，此时处理出来的数据没有进过包装，用户肯定看不懂，所以将数据交由jsp页面处理 ，jsp虽然叫页面但是并不会把jsp交给用户， jsp其实就是一个servlet（程序）他将数据在处理一下（比如说：此时的数据是一个list 集合 ，jsp将他遍历出来，嵌到html中，此时一个用户可以看懂的页面就完成了）然后在返回给控制器
5 控制器拿到html页面返回给用户

下面展示如何搭键一个SpringMvc的项目

需求：查询商品信息
new Project
导包
pom.xml

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>4.2.4.RELEASE</version>
</dependency>

        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.38</version>
</dependency>
  <!-- https://mvnrepository.com/artifact/com.mchange/c3p0 -->
<dependency>
    <groupId>com.mchange</groupId>
    <artifactId>c3p0</artifactId>
    <version>0.9.2.1</version>
</dependency>

  <!-- https://mvnrepository.com/artifact/org.springframework/spring-aspects -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aspects</artifactId>
    <version>4.2.4.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>4.2.4.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>1.7.25</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>4.2.4.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.springframework/spring-orm -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-orm</artifactId>
    <version>4.2.4.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-test</artifactId>
    <version>4.2.4.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.springframework/spring-web -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-web</artifactId>
    <version>4.2.4.RELEASE</version>
</dependency>

    <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>4.2.4.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-beans</artifactId>
    <version>4.2.4.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-expression</artifactId>
    <version>4.2.4.RELEASE</version>
</dependency>

前端控制器的配置（WEB.xml）

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0"
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_3_0.xsd">


 <!-- 配置Spring Mvc前端控制器 -->
 <servlet>
     <servlet-name>SpringMvc</servlet-name>
     <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
   <!-- 指定SpringMvc配置文件
      如果没有配置那么默认找/WEB-INF/[servlet的名称]-servlet.xml
      (即：classpath:[servlet的名称]-servlet.xml)
   -->
   <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:SpringMvc.xml</param-value>
   </init-param>
 </servlet>

 <!-- 映射 -->
 <servlet-mapping>
     <servlet-name>SpringMvc</servlet-name>
   <!-- 拦截规则：（适用于SpringMvc)
      1. /* 拦截所有 包括jsp js png css

      2. *.action  *.do 拦截以do action 结尾的请求
      3. /  拦截所有（不包括jsp) （包含js png css）
    -->
     <url-pattern>*.action</url-pattern>
 </servlet-mapping>

</web-app>

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:p="http://www.springframework.org/schema/p"
   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/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">

   <!-- 注解扫描 -->
   <context:component-scan base-package="com.Google.controller" />

</beans>

bean

package com.Google.bean;

import java.util.Date;

public class Items {
    private Integer id;

    private String name;

    private Float price;

    private String pic;

    private Date createtime;

    private String detail;

    /**
    * @param i
    * @param string
    * @param j
    * @param date
    * @param string2
    */

   public Integer getId() {
        return id;
    }

    public Items(Integer id, String name, Float price, Date createtime, String detail) {
      super();
      this.id = id;
      this.name = name;
      this.price = price;
      this.createtime = createtime;
      this.detail = detail;
   }

   public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name == null ? null : name.trim();
    }

    public Float getPrice() {
        return price;
    }

    public void setPrice(Float price) {
        this.price = price;
    }

    public String getPic() {
        return pic;
    }

    public void setPic(String pic) {
        this.pic = pic == null ? null : pic.trim();
    }

    public Date getCreatetime() {
        return createtime;
    }

    public void setCreatetime(Date createtime) {
        this.createtime = createtime;
    }

    public String getDetail() {
        return detail;
    }

    public void setDetail(String detail) {
        this.detail = detail == null ? null : detail.trim();
    }
}

controller

/**
 *
 */
package com.Google.controller;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

import com.Google.bean.Items;

/**
 * 商品管理
 * @author Administrator
 *
 */
@Controller
public class ItemController {

    @RequestMapping(value = "/item/itemlist.action")
    public ModelAndView itemlist ()
    {
        List<Items> list = new ArrayList<>();
        list.add(new Items(1, "1iphone8", (float) 2399, new Date(), "质量好！1"));
        list.add(new Items(2, "2iphone8", (float) 2399, new Date(), "质量好！2"));
        list.add(new Items(3, "3iphone8", (float) 2399, new Date(), "质量好！3"));
        list.add(new Items(4, "4iphone8", (float) 2399, new Date(), "质量好！4"));
        list.add(new Items(5, "5iphone8", (float) 2399, new Date(), "质量好！5"));
        list.add(new Items(6, "6iphone8", (float) 2399, new Date(), "质量好！6"));


        ModelAndView mav = new ModelAndView() ;
//        传递一个bean过去，bean中封装数据
        mav.addObject("itemList" , list) ;
//        设置视图
        mav.setViewName("/WEB-INF/jsp/itemList.jsp");

        return mav ;
    }

}

jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt"  prefix="fmt"%>
<!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>查询商品列表</title>
</head>
<body>
<form action="${pageContext.request.contextPath }/item/queryitem.action" method="post">
查询条件：
<table width="100%" border=1>
<tr>
<td><input type="submit" value="查询"/></td>
</tr>
</table>
商品列表：
<table width="100%" border=1>
<tr>
   <td>商品名称</td>
   <td>商品价格</td>
   <td>生产日期</td>
   <td>商品描述</td>
   <td>操作</td>
</tr>
<c:forEach items="${itemList }" var="item">
<tr>
   <td>${item.name }</td>
   <td>${item.price }</td>
   <td><fmt:formatDate value="${item.createtime}" pattern="yyyy-MM-dd HH:mm:ss"/></td>
   <td>${item.detail }</td>

   <td><a href="${pageContext.request.contextPath }/itemEdit.action?id=${item.id}">修改</a></td>

</tr>
</c:forEach>

</table>
</form>
</body>

</html>