springmvc入门

白未

已于 2022-08-20 20:09:18 修改

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文章标签： spring java 前端

于 2022-08-17 11:36:37 首次发布

本文链接：https://blog.youkuaiyun.com/yzq102873/article/details/126370261

版权

本文主要介绍了Spring MVC的基础知识，包括什么是Spring MVC、别称、Hello World实现步骤、工作原理，以及常用注解和返回值的讲解，适合初学者入门。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1、首先在pom文件中添加Spring-mvc的依赖

一、springmvc简介

1、什么是springmvc

Spring Web MVC是一种基于Java的实现了MVC设计模式的、请求驱动类型的、轻量级Web框架。

2、别称

①视图层框架 Springmvc部分功能是向用户渲染展示数据

②控制层框架 DispatcherServlet：接收浏览器端的任意请求然后

寻找对应的子控制器(适配器*Adapter) 处理浏览器请求

二、helloworld实现

1、首先在pom文件中添加Spring-mvc的依赖

 <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>${spring.version}</version>
      </dependency>

2、添加springmvc框架配置

1.扫描base-package
   定义base-package
   开启注解扫描
   开启动态代理
2.配置视图解析器
   本地资源视图解析器：InternalResourceViewResolver
       <property name="prefix" value="/"/>
   <property name="suffix" value=".jsp"/>
       前缀：prefix
       后缀：suffix
   多功能视图解析器
3.做静态资源映射

<?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" xmlns:aop="http://www.springframework.org/schema/aop"
       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-4.3.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    <!-- 通过context:component-scan元素扫描指定包下的控制器-->
    <!--1) 扫描com.javaxl.zf及子子孙孙包下的控制器(扫描范围过大，耗时)-->
    <aop:aspectj-autoproxy/>
    <context:component-scan base-package="com.zking.ssm"/>

    <!--2) 此标签默认注册DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter -->
    <!--两个bean，这两个bean是spring MVC为@Controllers分发请求所必须的。并提供了数据绑定支持，-->
    <!--@NumberFormatannotation支持，@DateTimeFormat支持，@Valid支持，读写XML的支持（JAXB），读写JSON的支持（Jackson）-->
    <mvc:annotation-driven></mvc:annotation-driven>

    <!--3) ViewResolver -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!-- viewClass需要在pom中引入两个包：standard.jar and jstl.jar -->
        <property name="viewClass"
                  value="org.springframework.web.servlet.view.JstlView"></property>
        <property name="prefix" value="/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <!--4) 单独处理图片、样式、js等资源 -->
    <!--<mvc:resources location="/css/" mapping="/css/**"/>-->
<!--    <mvc:resources location="/images/" mapping="/images/**"/>-->
    <!--<mvc:resources location="/js/" mapping="/js/**"/>-->


</beans>

3、在web.xml中配置：

Spring与web容器的集成：监听器
SpringMVC与web容器的集成：servlet DispatcherServelt

<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">
  <display-name>Archetype Created Web Application</display-name>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
  </context-param>
  <!-- 读取Spring上下文的监听器 -->
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <!-- Spring MVC servlet -->
  <servlet>
    <servlet-name>SpringMVC</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!--此参数可以不配置，默认值为：/WEB-INF/springmvc-servlet.xml-->
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>/WEB-INF/springmvc-servlet.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
    <!--web.xml 3.0的新特性，是否支持异步-->
    <async-supported>true</async-supported>
  </servlet>
  <servlet-mapping>
    <servlet-name>SpringMVC</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
</web-app>

package com.zking.ssm.controller;

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

        import javax.servlet.http.HttpServletRequest;

/**
 * @author 白未
 * @site 3185579318
 * @company xxx公司
 * @create  2022-08-18 16:59
 */
//被Controller标记的类会交给spring进行管理

/**
 * @Controller
 * @Service
 * @Repository
 * @Component
 */
//以上四个都代表被spring容器进行管理
@Controller
public class HelloController {
    //自定义mvc 浏览器发送请求http://localhost:8080/hello/hello.action?methodName=hello
    //springmvc 浏览器发送请求http://localhost:8080/helloReq

    //简写版本
    @RequestMapping("helloReq")
    public String hello(){
        System.out.println("颠颠");
        return "hello";
    }

    @RequestMapping("/hello2")
    public ModelAndView hello2(HttpServletRequest req){
        ModelAndView mv = new ModelAndView();
        mv.setViewName("hello");
        mv.addObject("msg","success...");
        return mv;
    }
}

三、Springmvc工作原理

1、浏览器发送请求(http://localhost:8080/helloReq)到中央控制器DispatcherServlet

2、中央控制器DispatcherServlet通过处理器映射HandlerMapping找到处理器适配器HandlerAdapter

3、执行HandlerAdapter，返回值ModelAndView进行渲染，得到view视图对象

5、最后DispatcherServlet会将视图对象返回给用户对象

HelloController.java

package com.zking.ssm.controller;

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

import javax.servlet.http.HttpServletRequest;

/**
 * @author 白未
 * @site 3185579318
 * @company xxx公司
 * @create  2022-08-18 16:59
 */
//被Controller标记的类会交给spring进行管理

/**
 * @Controller
 * @Service
 * @Repository
 * @Component
 */
//以上四个都代表被spring容器进行管理
@Controller
public class HelloController {
    //自定义mvc 浏览器发送请求http://localhost:8080/hello/hello.action?methodName=hello
    //springmvc 浏览器发送请求http://localhost:8080/helloReq

    //简写版本
    @RequestMapping("helloReq")
    public String hello(){
        System.out.println("颠颠");
        return "hello";
    }

    @RequestMapping("/hello2")
    public ModelAndView hello2(HttpServletRequest req){
        ModelAndView mv = new ModelAndView();
        mv.setViewName("hello");
        mv.addObject("msg","success...");
        return mv;
    }
}

hello.jsp

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2022/8/18
  Time: 17:21
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
颠颠
${msg}
</body>
</html>

结果：

四、Spring常用注解及返回值

BookMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.zking.ssm.mapper.BookMapper" >
  <resultMap id="BaseResultMap" type="com.zking.ssm.model.Book" >
    <constructor >
      <idArg column="bid" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="bname" jdbcType="VARCHAR" javaType="java.lang.String" />
      <arg column="price" jdbcType="REAL" javaType="java.lang.Float" />
    </constructor>
  </resultMap>
  <sql id="Base_Column_List" >
    bid, bname, price
  </sql>
  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select
    <include refid="Base_Column_List" />
    from t_mvc_book
    where bid = #{bid,jdbcType=INTEGER}
  </select>

  <select id="selectByIn" resultMap="BaseResultMap" parameterType="java.util.List" >
    select
    <include refid="Base_Column_List" />
    from t_mvc_book
    where bid in
    <foreach collection="bookIds" open="(" close=")" separator="," item="bid">
      #{bid}
    </foreach>
  </select>

  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    delete from t_mvc_book
    where bid = #{bid,jdbcType=INTEGER}
  </delete>
  <insert id="insert" parameterType="com.zking.ssm.model.Book" >
    insert into t_mvc_book (bid, bname, price
      )
    values (#{bid,jdbcType=INTEGER}, #{bname,jdbcType=VARCHAR}, #{price,jdbcType=REAL}
      )
  </insert>
  <insert id="insertSelective" parameterType="com.zking.ssm.model.Book" >
    insert into t_mvc_book
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="bid != null" >
        bid,
      </if>
      <if test="bname != null" >
        bname,
      </if>
      <if test="price != null" >
        price,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="bid != null" >
        #{bid,jdbcType=INTEGER},
      </if>
      <if test="bname != null" >
        #{bname,jdbcType=VARCHAR},
      </if>
      <if test="price != null" >
        #{price,jdbcType=REAL},
      </if>
    </trim>
  </insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.zking.ssm.model.Book" >
    update t_mvc_book
    <set >
      <if test="bname != null" >
        bname = #{bname,jdbcType=VARCHAR},
      </if>
      <if test="price != null" >
        price = #{price,jdbcType=REAL},
      </if>
    </set>
    where bid = #{bid,jdbcType=INTEGER}
  </update>
  <update id="updateByPrimaryKey" parameterType="com.zking.ssm.model.Book" >
    update t_mvc_book
    set bname = #{bname,jdbcType=VARCHAR},
      price = #{price,jdbcType=REAL}
    where bid = #{bid,jdbcType=INTEGER}
  </update>

  <select id="selectBooksLike1" resultType="com.zking.ssm.model.Book" parameterType="java.lang.String">
  select * from t_mvc_book where bname like #{bname}
</select>
  <select id="selectBooksLike2" resultType="com.zking.ssm.model.Book" parameterType="java.lang.String">
  select * from t_mvc_book where bname like '${bname}'
</select>
  <select id="selectBooksLike3" resultType="com.zking.ssm.model.Book" parameterType="java.lang.String">
  select * from t_mvc_book where bname like concat('%',#{bname},'%')
</select>


  <select id="list1" resultMap="BaseResultMap">
  select * from t_mvc_book
</select>
  <select id="list2" resultType="com.zking.ssm.model.Book">
  select * from t_mvc_book
</select>
  <select id="list3" resultType="com.zking.ssm.model.Book" parameterType="com.zking.ssm.model.BookVo">
    select * from t_mvc_book where bid in
    <foreach collection="bookIds" open="(" close=")" separator="," item="bid">
      #{bid}
    </foreach>
  </select>
  <select id="list4" resultType="java.util.Map">
  select * from t_mvc_book
</select>
  <select id="list5" resultType="java.util.Map" parameterType="java.util.Map">
  select * from t_mvc_book where bid = #{bid}
</select>

  <select id="listPager" resultType="java.util.Map" parameterType="java.util.Map">
  select * from t_mvc_book where bname like concat(concat('%',#{bname}),'%')
</select>

  <select id="list6" resultType="com.zking.ssm.model.Book" parameterType="com.zking.ssm.model.BookVo">
    select * from t_mvc_book
    <where>
      <if test="null != min and min != ''">
        <![CDATA[  and #{min} < price ]]>
      </if>
      <if test="null != max and max != ''">
        <![CDATA[ and #{max} > price ]]>
      </if>
    </where>
  </select>

  <select id="list7" resultType="com.zking.ssm.model.Book" parameterType="com.zking.ssm.model.BookVo">
    select * from t_mvc_book
    <where>
      <if test="null != min and min != ''">
        and #{min} &lt; price
      </if>
      <if test="null != max and max != ''">
        and #{max} &gt; price
      </if>
    </where>
  </select>

</mapper>

BookMapper

package com.zking.ssm.mapper;

import com.zking.ssm.model.Book;
import com.zking.ssm.model.BookVo;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;

import java.util.List;
import java.util.Map;

@Repository
public interface BookMapper {
    int deleteByPrimaryKey(Integer bid);

    int insert(Book record);

    int insertSelective(Book record);

    Book selectByPrimaryKey(Integer bid);

    int updateByPrimaryKeySelective(Book record);

    int updateByPrimaryKey(Book record);

    //通过in关键字进行查询，讲解foreach标签的使用
    //如果说参数是非实体类(book,Order,....)，那么记得加上注解@param,bookIds是对应collection属性的
    List<Book> selectByIn(@Param("bookIds") List bookIds);

    List<Book> selectBooksLike1(@Param("bname") String bname);
    List<Book> selectBooksLike2(@Param("bname") String bname);
    List<Book> selectBooksLike3(@Param("bname") String bname);

    //list1、list2的结论是：对于单表查询而言，可以用Resutmap/resultType接收，但是多表必须用Resutmap接收
    List<Book> list1();
    List<Book> list2();
    //如果要传入多个查询参数，必须以对象的方式进行传递
    List<Book> list3(BookVo vo);

//    不管返回1条数据，还是多条数据，都应该用java.util.Map进行接受
//    如果是1条数据，那么返回值是Map
//    如果返回是多条数据，那么返回值是List<Map>
    List<Map> list4();
    Map list5(Map map);

    //利用第三方插件进行分页
    List<Map> listPager(Map map);

    /**
     * 处理特殊字符
     * @param bookVo
     * @return
     */
    List<Book> list6(BookVo bookVo);


    /**
     * 处理特殊字符
     * @param bookVo
     * @return
     */
    List<Book> list7(BookVo bookVo);

}

BookBiz

package com.zking.ssm.biz;

import com.zking.ssm.model.Book;
import com.zking.ssm.model.BookVo;
import com.zking.ssm.util.PageBean;

import java.util.List;
import java.util.Map;

/**
 * @author 白未
 * @site 3185579318
 * @company xxx公司
 * @create  2022-08-11 3:00
 */
public interface BookBiz {
    int deleteByPrimaryKey(Integer bid);

    int insert(Book record);

    int insertSelective(Book record);

    Book selectByPrimaryKey(Integer bid);

    int updateByPrimaryKeySelective(Book record);

    int updateByPrimaryKey(Book record);

    public List<Book> selectBooksLike1(String bname);
    public List<Book> selectBooksLike2(String bname);
    public List<Book> selectBooksLike3(String bname);

    List<Book> list1();
    List<Book> list2();
    List<Book> list3(BookVo vo);
    List<Map> list4();
    Map list5(Map map);

    List<Map> listPager(Map map, PageBean pageBean);

    List<Book> list6(BookVo bookVo);

    List<Book> list7(BookVo bookVo);

}

BookBizImpl

package com.zking.ssm.biz.impl;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.zking.ssm.biz.BookBiz;
import com.zking.ssm.mapper.BookMapper;
import com.zking.ssm.model.BookVo;
import com.zking.ssm.util.PageBean;
import com.zking.ssm.model.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Map;

/**
 * @author 白未
 * @site 3185579318
 * @company xxx公司
 * @create  2022-08-11 3:04
 */
@Service
public class BookBizImpl implements BookBiz {
    @Autowired
    private BookMapper bookMapper;

//    public BookMapper getBookMapper() {
//        return bookMapper;
//    }
//
//    public void setBookMapper(BookMapper bookMapper) {
//        this.bookMapper = bookMapper;
//    }

    @Override
    public int deleteByPrimaryKey(Integer bid) {
        return bookMapper.deleteByPrimaryKey(bid);
    }

    @Override
    public int insert(Book record) {
        return bookMapper.insert(record);
    }

    @Override
    public int insertSelective(Book record) {
        return bookMapper.insert(record);
    }

    @Override
    public Book selectByPrimaryKey(Integer bid) {

        return bookMapper.selectByPrimaryKey(bid);
    }

    @Override
    public int updateByPrimaryKeySelective(Book record) {
        return bookMapper.updateByPrimaryKeySelective(record);
    }

    @Override
    public int updateByPrimaryKey(Book record) {
        return bookMapper.updateByPrimaryKey(record);
    }

    //    @Override
    public List<Book> selectByIn(List bookIds) {
        return bookMapper.selectByIn(bookIds);
    }

    public List<Book> selectBooksLike1(String bname){
        return bookMapper.selectBooksLike1(bname);
    }
    public List<Book> selectBooksLike2(String bname){
        return bookMapper.selectBooksLike2(bname);
    }
    public List<Book> selectBooksLike3(String bname){
        return bookMapper.selectBooksLike3(bname);
    }

    @Override
    public List<Book> list1() {
        return bookMapper.list1();
    }

    @Override
    public List<Book> list2() {
        return bookMapper.list2();
    }

    @Override
    public List<Book> list3(BookVo vo) {
        return bookMapper.list3(vo);
    }

    @Override
    public List<Map> list4() {
        return bookMapper.list4();
    }

    @Override
    public Map list5(Map map) {
        return bookMapper.list5(map);
    }

    @Override
    public List<Map> listPager(Map map, PageBean pageBean) {
        return bookMapper.listPager(map);
    }
//    public List<Map> listPager(Map map, PageBean pageBean) {
//        //pageHelper分页插件相关的代码
//        if(pageBean!=null&&pageBean.isPagination()){
//            PageHelper.startPage(pageBean.getPage(),pageBean.getRows());
//        }
//        List<Map> maps = bookMapper.listPager(map);
//        if(pageBean!=null&&pageBean.isPagination()){
//            //处理查询结果的前提是需要分页的
//            PageInfo info = new PageInfo(maps);
//            pageBean.setTotal(info.getTotal()+"");
//        }
//
//        return maps;
//    }

    @Override
    public List<Book> list6(BookVo bookVo) {
        return bookMapper.list6(bookVo);
    }

    @Override
    public List<Book> list7(BookVo bookVo) {
        return bookMapper.list7(bookVo);
    }
}

BookController

package com.zking.ssm.controller;

import com.zking.ssm.biz.BookBiz;
import com.zking.ssm.model.Book;
import com.zking.ssm.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author 白未
 * @site 3185579318
 * @company xxx公司
 * @create  2022-08-20 18:40
 *
 * @RequestMapping 加在类上面称窄化路径，相当于包的概念
 */
@Controller
@RequestMapping("/book")
public class BookController {
    @Autowired
    private BookBiz bookBiz;

    @RequestMapping("/list")
    public String hello(HttpServletRequest request){
        System.out.println("颠颠");
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        Map map = new HashMap();
        String bname = request.getParameter("bname");
        map.put("banme",bname);
        List<Map> maps = this.bookBiz.listPager(map, pageBean);
        request.setAttribute("lst",maps);
        return "hello";
    }

    @RequestMapping("/add")
    public String add(Book book){
        this.bookBiz.insertSelective(book);
        return "redirect:/book/list";
    }

    @RequestMapping("/edit")
    public String edit(Book book){
        this.bookBiz.updateByPrimaryKeySelective(book);
        return "redirect:/book/list";
    }

    @RequestMapping("/del/{bid}")
    public String del(@PathVariable("bid")Integer bid){
        this.bookBiz.deleteByPrimaryKey(bid);
        return "redirect:/book/list";
    }
}

index.jsp

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2022/8/20
  Time: 19:12
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<a href="${pageContext.request.contextPath}/book/list?bname=圣">查询所有</a>
<a href="${pageContext.request.contextPath}/book/add?bid=2&bname=dd&price=9.9">新增</a>
<a href="${pageContext.request.contextPath}/book/edit?bid=2&bname=dinadian&price=9.0">修改</a>
<a href="${pageContext.request.contextPath}/book/del/2">删除</a>
</body>
</html>

hello.jsp

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2022/8/18
  Time: 17:21
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
颠颠
${msg}
<hr>
${lst}
<c:forEach items="${lst}" var="l">
    ${l.bid} : ${l.bname}<br>
</c:forEach>
</body>
</html>

1、常用注解

①、@controller：

用来定义控制层的组件

②、@requestMapping：

是一个用来处理请求地址映射的注解，可用于类或方法上。用于类上，表示类中的所有响应请求的方法都是以该地址作为父路径。

③、@pathvariable：

可以用来映射URL中的占位符到目标方法的参数中路径传参

2、返回值

①String

②ModelAndView

3、转发与重定向的设置

"hello" 转发到 /hello.jsp

 @RequestMapping("/list")
    public String hello(HttpServletRequest request){
        System.out.println("颠颠");
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        Map map = new HashMap();
        String bname = request.getParameter("bname");
        map.put("banme",bname);
        List<Map> maps = this.bookBiz.listPager(map, pageBean);
        request.setAttribute("lst",maps);
        return "hello";
    }

"redirect:/book/list"

@RequestMapping("/add")
    public String add(Book book){
        this.bookBiz.insertSelective(book);
        return "redirect:/book/list";
    }

    @RequestMapping("/edit")
    public String edit(Book book){
        this.bookBiz.updateByPrimaryKeySelective(book);
        return "redirect:/book/list";
    }

    @RequestMapping("/del/{bid}")
    public String del(@PathVariable("bid")Integer bid){
        this.bookBiz.deleteByPrimaryKey(bid);
        return "redirect:/book/list";
    }