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  • SpringMVC入门

    目的:

      Spring简介

    1. 什么是springMVC
    2. SpringMVC处理请求的流程
    3. SpringMVC核心开发步骤
    4. SpringMVC的组件
    5. 常用注解

      项目中配置SpringMVC

      Spring之helloword实现五种结果集处理

      Spring之增删查改案例

      Springmvc静态资源处理


     Spring简介

    • 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。

    • SpringMVC处理请求的流程

      1 首先用户发送请求-->DispatherServlet
      2 DispatcherServlet-->HandlerMapping
      3 DispatcherServlet-->HandlerAdapter
      4 HandlerAdapter-->处理器功能处理方法的调用
      5 ModelAndView的逻辑视图名-->ViewRecolver
      6 View-->渲染
      7 返回控制权给DispatcherServlet,由DispatcherServlet返回呼应给用户,流程结束

    • SpringMVC核心开发步骤

       1 DispatcherServlet在web.xml中的部署描述,从而拦截请求到springMVC
      2 HandlerMapping的配置,从而将请求映射到处理器
      3 HandlerAdapter的配置,从而支持多种类型的处理器
      4 处理器(页面控制器)的配置,从而刊行功能处理
      5 ViewResolver的配置,从而将逻辑视图名解析为具体的视图技术

    • SpringMVC的组件

      1 前端控制器(DispatcherServlet)
      2 请求到处理器映射(HandlerMapping)
      3 处理器适配器(HandlerAdapter)
      4 视图解析器(ViewResolver)
      5 处理器或页面控制器(Controller)
      6 验证器(Validator)
      6 命令对象(Command 请求参数绑定到的对象就叫命令对象)
      7 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)

    • 常用注解

    1 @Controller:用于标识处理器类

    2 @RequestMapping:请求到处理器功能方法的映射规则,可定义到类和方法
    常用参数:value、method
    可将@RequestMapping标签定义到类名处窄化路径

    3 @RequestParam:请求参数到处理器功能处理方法的方法参数上的绑定
    常用参数:value、required、defaultValue
    注:required设置成false的参数类型必须是引用类型,因为基本数据类型是不能为null的

    4 @ModelAttribute:请求参数到命令对象的绑定
    常用参数:value
    4.1 可用@ModelAttribute标注方法参数,方法参数会被添加到Model对象中(作用:向视图层传数据)
    4.2 可用@ModelAttribute标注一个非请求处理方法,此方法会在每次调用请求处理方法前被调用(作用:数据初始化)
    4.3 可用@ModelAttribute标注方法,方法返回值会被添加到Model对象中(作用:向视图层传数据)
    但此方法视图的逻辑图就会根据请求路径解析,例如:a/test42 --> /WEB-INF/a/test42.jsp
    太麻烦几乎不用,不用直接保存到Model或ModelAndView中

    5 @SessionAttributes:指定ModelMap中的哪些属性需要转存到session
    常用参数:value、types
    注1:必须放到class类名处

    6 @InitBinder(本章暂不介绍):用于将请求参数转换到命令对象属性的对应类型

    7 @RequestBody(重要~~~~~):用于目前比较流行的ajax开发的数据绑定(即提交数据的类型为json格式)
    注1:使用@RequestBody注解的时候,前台的Content-Type必须要改为application/json,
    如果没有更改,前台会报错415(Unsupported Media Type)。
    后台日志就会报错Content type ‘application/x-www-form-urlencoded;charset=UTF-8’ not supported。
    这些错误Eclipse下Tomcat是不会显示错误信息的,只有使用了日志才会显示


      项目中配置SpringMVC

       POM.xml

      在项目中添加springmvc和JSTL依赖以及tomcat-jsp-api所需要的一些jar包

    <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-webmvc</artifactId>
                <version>${spring.version}</version>
    </dependency>
    <!-- ********************** JSTL依赖 ********************** -->
    <!-- 缺少下面的这两个jar包会报java.lang.NoClassDefFoundError: javax/servlet/jsp/jstl/core/Config-->
    <!-- 原因:org.springframework.web.servlet.view.JstlView在视图解析时需要这二个jar包-->
    
     <dependency>
                <groupId>jstl</groupId>
                <artifactId>jstl</artifactId>
                <version>1.2</version>
            </dependency>
            <dependency>
                <groupId>taglibs</groupId>
                <artifactId>standard</artifactId>
                <version>1.1.2</version>
     </dependency>
    
    <!--tomcat-jsp-api-->
     <tomcat-jsp-api.version>8.0.47</tomcat-jsp-api.version>
    
     <dependency>
          <groupId>org.apache.tomcat</groupId>
          <artifactId>tomcat-jsp-api</artifactId>
          <version>${tomcat-jsp-api.version}</version>
        </dependency>

      在WEB-INF下添加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: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.ht"/>
    
        <!--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 视图分析器-->
        <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>
    
    <!--    &lt;!&ndash;4) 单独处理图片、样式、js等资源 &ndash;&gt;-->
    <!--    &lt;!&ndash;<mvc:resources location="/css/" mapping="/css/**"/>&ndash;&gt;-->
    <!--    <mvc:resources location="/static/img" mapping="/static/img/**"/>-->
    <!--    &lt;!&ndash;<mvc:resources location="/js/" mapping="/js/**"/>&ndash;&gt;-->
    </beans>

      修改web.xml

    <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>
    
      <welcome-file-list>
        <welcome-file>login.jsp</welcome-file>
      </welcome-file-list>
    
      <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和web项目集成end -->
      <!-- 防止Spring内存溢出监听器 -->
      <listener>
        <listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>
      </listener>
    
      <!-- 中文乱码处理 -->
      <filter>
        <filter-name>encodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <!--web.xml 3.0的新特性,是否支持异步-->
        <async-supported>true</async-supported>
        <init-param>
          <param-name>encoding</param-name>
          <param-value>UTF-8</param-value>
        </init-param>
      </filter>
      <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
      </filter-mapping>
      <!-- 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>

      


    Spring之helloword实现五种结果集处理

     创建一个类:HelloController

    package com.ht.controller;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import javax.servlet.http.HttpServletRequest;
    /**
     * @author 黄大娘
     * @company dogson有限公司
     * @create  2019-09-28 11:27
     *
     * 关于结果集处理的五种情况
     * 1、转发到页面(webapp下)
     * 2、转发到action
     * 3、重定向到页面(webapp下)
     * 4、重定向到action
     * 5、转发到 WEB-INF下的页面
     */
    @Controller
    public class HelloController {
        /**
         * 转发到页面
         * @return
         */
        @RequestMapping("hello")
       public String  hello(HttpServletRequest request){
            request.setAttribute("msg","转发到页面的方式");
           return "hello";
       }
        /**
         * 重定向到action
         * @param request
         * @return
         */
        @RequestMapping("hello2")
        public String redirectPage(HttpServletRequest request){
            request.setAttribute("msg","重定向到action的方式");
            return "redirect:hello";
        }
        /**
         * 重定向到页面
         * @param request
         * @return
         */
        @RequestMapping("hello3")
        public String redirectPage2(HttpServletRequest request){
    //        request.setAttribute("msg","重定向到页面的方式");
            Object msg = request.getAttribute("msg");
            return "redirect:/hello.jsp";
        }
    
        /**
         * 转发到action
         * @param request
         * @return
         */
        @RequestMapping("hello4")
        public String forwardAction(HttpServletRequest request){
            request.setAttribute("msg","转发到action的方式");
            return "forward:hello3";
        }
    
        /**
         * 转发到WEB-INF下的页面
         * @param request
         * @return
         */
        @RequestMapping("hello5")
        public String forwardAction2(HttpServletRequest request){
            request.setAttribute("msg","转发到WEB-INF下的页面方式");
            return "abc";
        }
    }

     前端显示 Hello.jsp

    <%--
      Created by IntelliJ IDEA.
      User: 2019091008
      Date: 2019/9/28
      Time: 22:27
      To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>黄大娘</title>
    </head>
    <body>
    hello~本是青灯不归客
    <br>
    ${msg}
    </body>
    </html>

    效果:


     Spring之增删查改案例

     后台方法 BookController

    package com.ht.controller;
    import com.ht.Util.PageBean;
    import com.ht.model.Book;
    import com.ht.service.BookService;
    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.List;
    import java.util.Map;
    
    /**
     * @author 黄大娘
     * @company dogson有限公司
     * @create  2019-09-29 0:40
     */
    @Controller
    @RequestMapping("/book")
    public class BookController  {
        @Autowired
        private BookService bookService;
    
        /**
         *查询
         * @param book
         * @param request
         * @return
         */
        @RequestMapping("/list")
        public String list(Book book, HttpServletRequest request){
            PageBean pageBean =new PageBean();
            pageBean.setRequest(request);
            List<Map> list = this.bookService.listPager(book, pageBean);
            request.setAttribute("bookList",list);
            request.setAttribute("pageBean",pageBean);
            return "bookList";
        }
    
        /**
         * 跳转新增或修改页面
         * @param book
         * @param request
         * @return
         */
        @RequestMapping("/preSave")
        public String preSave(Book book, HttpServletRequest request){
            if(book.getBid() !=null){
                Book b = this.bookService.selectByPrimaryKey(book.getBid());
                request.setAttribute("b",b);
            }
            return "bookEdit";
        }
    
        /**
         * 新增
         * @param book
         * @param request
         * @return
         */
        @RequestMapping("/add")
        public String add(Book book, HttpServletRequest request){
            this.bookService.insert(book);
            return "redirect:/book/list"; //重定向
        }
    
        /**
         * 删除
         * @param bid
         * @param request
         * @return
         */
        @RequestMapping("/del/{bid}")
        public String del(@PathVariable(value = "bid") Integer bid, HttpServletRequest request){
            this.bookService.deleteByPrimaryKey(bid);
            return "redirect:/book/list";
        }
    
        /**
         * 修改
         * @param book
         * @param request
         * @return
         */
        @RequestMapping("/edit")
        public String edit(Book book, HttpServletRequest request){
            this.bookService.updateByPrimaryKeySelective(book);
            return "redirect:/book/list";
        }
    }

     前端调用:

      bookList.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 prefix="z" uri="/huang" %>
    <%@ taglib uri="/huang" prefix="z" %> <!--分页-->
    <!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>
        <script type="text/javascript">
            function add(){
                // window.location.href = "bookEdit.jsp";
                window.location.href="${pageContext.request.contextPath}/book/preSave";
            }
    
            function update(bid){
                window.location.href = "${pageContext.request.contextPath}/book/preSave?bid="+bid;
            }
    
            function del(bid){
                window.location.href = "${pageContext.request.contextPath}/book/del/"+bid;
            }
        </script>
    </head>
    <body>
    <form action="${pageContext.request.contextPath}/book/list"
          method="post">
        书名:<input type="text" name="bname"> <input type="submit" value="确定">
    </form>
    <button onclick="add();">新增</button>
    <table border="1" width="100%">
        <tr>
            <td>编号</td>
            <td>名称</td>
            <td>价格</td>
            <td>操作</td>
        </tr>
        <c:forEach items="${bookList }" var="b">
            <tr>
                <td>${b.bid }</td>
                <td>${b.bname }</td>
                <td>${b.price }</td>
                <td>
                    <button onclick="update(${b.bid });">修改</button>&nbsp;&nbsp;&nbsp;
                    <button onclick="del(${b.bid });">删除</button>
                </td>
            </tr>
        </c:forEach>
    </table>
    <!--分页-->
    <z:page pageBean="${pageBean}"></z:page>
    </body>
    </html>

      bookEdit.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>
        <script type="text/javascript">
            function doSubmit(bid){
                var bookForm = document.getElementById("bookForm");
                if(bid){
                    //修改时候执行
                    bookForm.action = '${pageContext.request.contextPath}/book/edit';
                }else{
                    //新增时候执行
                    bookForm.action = '${pageContext.request.contextPath}/book/add';
                }
                bookForm.submit();
            }
        </script>
    </head>
    <body>
    <form id="bookForm" action="" method="post">
        bid:<input type="text" name="bid" value="${b.bid }"><br>
        bname:<input type="text" name="bname" value="${b.bname }"><br>
        price:<input type="text" name="price" value="${b.price }"><br>
        <input type="submit" value="提交" onclick="doSubmit('${b.bid }');"><br>
    </form>
    </body>
    </html>
    分页相关工具:
    PageTag
    package com.ht.Util;
    
    import javax.servlet.jsp.JspException;
    import javax.servlet.jsp.JspWriter;
    import javax.servlet.jsp.tagext.BodyTagSupport;
    import java.io.IOException;
    import java.util.Map;
    import java.util.Map.Entry;
    import java.util.Set;
    
    
    public class PageTag extends BodyTagSupport {
    
        private static final long serialVersionUID = 1L;
        private PageBean pageBean;
        public PageBean getPageBean() {
            return pageBean;
        }
        public void setPageBean(PageBean pageBean) {
            this.pageBean = pageBean;
        }
        @Override
        public int doStartTag() throws JspException {
            JspWriter out = pageContext.getOut();
            try {
                out.print(toHTML());
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return super.doStartTag();
        }
        private String toHTML() {
            StringBuffer sb = new StringBuffer();
            /*
             * 拼接向后台提交数据的form表单
             *     注意:拼接的form表单中的page参数是变化的,所以不需要保留上一次请求的值
             */
            sb.append("<form id='pageBeanForm' action='"+pageBean.getUrl()+"' method='post'>");
            sb.append("<input type='hidden' name='page'>");
            Map<String, String[]> parameterMap = pageBean.getMap();
            if(parameterMap != null && parameterMap.size() > 0) {
                Set<Entry<String, String[]>> entrySet = parameterMap.entrySet();
                for (Entry<String, String[]> entry : entrySet) {
                    if(!"page".equals(entry.getKey())) {
                        String[] values = entry.getValue();
                        for (String val : values) {
                            sb.append("<input type='hidden' name='"+entry.getKey()+"' value='"+val+"'>");
                        }
                    }
                }
            }
            sb.append("</form>");
            
            /*
             * 展示的分页条
             */
            sb.append("<div style='text-align: right; font-size: 12px;'>");
            sb.append("每页"+pageBean.getRows()+"条,共"+pageBean.getTotal()+"条,第"+pageBean.getPage()+"页,共"+pageBean.getMaxPage()+"页&nbsp;&nbsp;<a href='javascript:gotoPage(1)'>首页</a>&nbsp;&nbsp;<a");
            sb.append(" href='javascript:gotoPage("+pageBean.getPreivousPage()+")'>上一页</a>&nbsp;&nbsp;<a");
            sb.append(" href='javascript:gotoPage("+pageBean.getNextPage()+")'>下一页</a>&nbsp;&nbsp;<a");
            sb.append(" href='javascript:gotoPage("+pageBean.getMaxPage()+")'>尾页</a>&nbsp;&nbsp;<input type='text'");
            sb.append(" id='skipPage'");
            sb.append(" style='text-align: center; font-size: 12px;  50px;'>&nbsp;&nbsp;<a");
            sb.append(" href='javascript:skipPage()'>Go</a>");
            sb.append("</div>");
            
            /*
             * 给分页条添加与后台交互的js代码
             */
            sb.append("<script type='text/javascript'>");
            sb.append("        function gotoPage(page) {");
            sb.append("            document.getElementById('pageBeanForm').page.value = page;");
            sb.append("            document.getElementById('pageBeanForm').submit();");
            sb.append("        }");
            sb.append("        function skipPage() {");
            sb.append("            var page = document.getElementById('skipPage').value;");
            sb.append("            if(!page || isNaN(page) || parseInt(page)<1 || parseInt(page)>"+pageBean.getMaxPage()+"){");
            sb.append("                alert('请输入1~N的数字');");
            sb.append("                return;");
            sb.append("            }");
            sb.append("            gotoPage(page);");
            sb.append("        }");
            sb.append("</script>");
            return sb.toString();
        }
    }

    Z.tld

    <?xml version="1.0" encoding="UTF-8" ?>
    
    <taglib xmlns="http://java.sun.com/xml/ns/j2ee"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
        version="2.0">
        
      <description>huang 1.1 core library</description>
      <display-name>haung core</display-name>
      <tlib-version>1.1</tlib-version>
      <short-name>z</short-name>
      <uri>/huang</uri>
    
     <tag>
        <name>page</name>
        <tag-class>com.ht.Util.PageTag</tag-class>
        <body-content>JSP</body-content>
        <attribute>
            <name>pageBean</name>
            <required>true</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
      </tag>
      
    </taglib>

    效果:


    Springmvc静态资源处理

       在webapp下创建一个static文件夹里面主专门放静态资源

     今天演示就用一张图片测试吧

    springmvc-servlet.xml

    <!--    &lt;!&ndash;4) 单独处理图片、样式、js等资源 &ndash;&gt;-->
    <!--    &lt;!&ndash;<mvc:resources location="/css/" mapping="/css/**"/>&ndash;&gt;-->
        <mvc:resources location="/static/img" mapping="/static/img/**"/>
    <!--    &lt;!&ndash;<mvc:resources location="/js/" mapping="/js/**"/>&ndash;&gt;-->

    效果:

     

    谢谢观看!

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  • 原文地址:https://www.cnblogs.com/huangting/p/11605559.html
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