学习笔记（狂神SpringMVC P17-P130）

1、SSM整合

2、AJAX

是一种在无需重新加载整个网页的情况下，能够更新部分网页的技术。

伪造Ajax

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>kuangshen</title>
</head>
<body>
 
<script type="text/javascript">
    window.onload = function(){
      
      
        var myDate = new Date();
        document.getElementById('currentTime').innerText = myDate.getTime();
    };
 
    function LoadPage(){
      
      
        var targetUrl =  document.getElementById('url').value;
        console.log(targetUrl);
        document.getElementById("iframePosition").src = targetUrl;
    }
 
</script>
 
<div>
    <p>请输入要加载的地址：<span id="currentTime"></span></p>
    <p>
        <input id="url" type="text" value="https://www.baidu.com/"/>
        <input type="button" value="提交" onclick="LoadPage()">
    </p>
</div>
 
<div>
    <h3>加载页面位置：</h3>
    <iframe id="iframePosition" style="width: 100%;height: 500px;"></iframe>
</div>
 
</body>
</html>

简单体验

- 创建一个SpringMVC的基本框架，配置好相关配置文件

applicationContext.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
        https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!-- 自动扫描指定的包，下面所有注解类交给IOC容器管理 -->
    <context:component-scan base-package="controller"/>
    <mvc:default-servlet-handler/>
    <mvc:annotation-driven/>

    <!-- 视图解析器 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
          id="internalResourceViewResolver">
        <!-- 前缀 -->
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <!-- 后缀 -->
        <property name="suffix" value=".jsp"/>
    </bean>
    <!--注解加载映射器、适配器，解决Json数据中文乱码问题-->

</beans>

web.xml

<?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_4_0.xsd"
         version="4.0">

  <!--DispatcherServlet-->
  <servlet>
    <servlet-name>DispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <!--一定要注意:我们这里加载的是总的配置文件，之前被这里坑了！-->
      <param-value>classpath:applicationContext.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>DispatcherServlet</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
  <!--encodingFilter-->
  <filter>
    <filter-name>encodingFilter</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>encodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

  <!--Session过期时间-->
  <session-config>
    <session-timeout>15</session-timeout>
  </session-config>

</web-app>

- AjaxController

package controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import pojo.User;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

@RestController
public class AjaxController {
    
    

    @RequestMapping("/a1")
    public void ajax1(String name, HttpServletResponse response) throws IOException {
    
    
        if ("admin".equals(name)) {
    
    
            response.getWriter().print("true");
        } else {
    
    
            response.getWriter().print("false");
        }
    }
}

- index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>$Title$</title>
    <script src="${pageContext.request.contextPath}/statics/js/jquery-3.6.min.js"></script>
    <script>
        function a1() {
      
      
            $.post({
      
      
                url: "${pageContext.request.contextPath}/a1",
                data: {
      
      'name': $("#uerName").val()},
                success: function (data, status) {
      
      
                    alert(data);
                    alert(status);
                }
            });
        }
    </script>
</head>
<body>
<%--onblur：失去焦点触发事件--%>
用户名:<input type="text" id="uerName" onblur="a1()"/>
</body>
</html>

启动tomcat测试！打开浏览器的控制台，当我们鼠标离开输入框的时候，可以看到发出了一个ajax的请求！是后台返回给我们的结果！测试成功！

Springmvc实现

实体类user

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    
    
 
    private String name;
    private int age;
    private String sex;
 
}

Controller

    @RequestMapping("/a2")
    public List<User> ajax2(){
    
    
        List<User> list = new ArrayList<User>();
        list.add(new User("1号",33,"男"));
        list.add(new User("2号",31,"女"));
        list.add(new User("3号",32,"男"));
        return list; //由于@RestController注解，将list转成json格式返回
    }

前端界面test.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<input type="button" id="btn" value="获取数据"/>
<table width="80%" align="center">
    <tr>
        <td>姓名</td>
        <td>年龄</td>
        <td>性别</td>
    </tr>
    <tbody id="content">
    </tbody>
</table>

<script src="${pageContext.request.contextPath}/statics/js/jquery-3.6.min.js"></script>

<script>

    $(function () {
      
      
        $("#btn").click(function () {
      
      
            $.post(
                "${pageContext.request.contextPath}/a2", function (data) {
      
      
                    let html = "";
                    for (let i = 0; i < data.length; i++) {
      
      
                        html += "<tr>" +
                            "<td>" + data[i].name + "</td>" +
                            "<td>" + data[i].age + "</td>" +
                            "<td>" + data[i].sex + "</td>" +
                            "</tr>"
                    }
                    $("#content").html(html);
                }
            );
        })
    })

</script>
</body>
</html>

注册页面

Controller

@RequestMapping("/a3")
public String ajax3(String name,String pwd){
    
    
    String msg = "";
    //模拟数据库中存在数据
    if (name!=null){
    
    
        if ("admin".equals(name)){
    
    
            msg = "OK";
        }else {
    
    
            msg = "用户名输入错误";
        }
    }
    if (pwd!=null){
    
    
        if ("123456".equals(pwd)){
    
    
            msg = "OK";
        }else {
    
    
            msg = "密码输入有误";
        }
    }
    return msg; //由于@RestController注解，将msg转成json格式返回
}

login.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>ajax</title>
    <script src="${pageContext.request.contextPath}/statics/js/jquery-3.1.1.min.js"></script>
    <script>
 
        function a1(){
      
      
            $.post({
      
      
                url:"${pageContext.request.contextPath}/a3",
                data:{
      
      'name':$("#name").val()},
                success:function (data) {
      
      
                    if (data.toString()=='OK'){
      
      
                        $("#userInfo").css("color","green");
                    }else {
      
      
                        $("#userInfo").css("color","red");
                    }
                    $("#userInfo").html(data);
                }
            });
        }
        function a2(){
      
      
            $.post({
      
      
                url:"${pageContext.request.contextPath}/a3",
                data:{
      
      'pwd':$("#pwd").val()},
                success:function (data) {
      
      
                    if (data.toString()=='OK'){
      
      
                        $("#pwdInfo").css("color","green");
                    }else {
      
      
                        $("#pwdInfo").css("color","red");
                    }
                    $("#pwdInfo").html(data);
                }
            });
        }
 
    </script>
</head>
<body>
<p>
    用户名:<input type="text" id="name" onblur="a1()"/>
    <span id="userInfo"></span>
</p>
<p>
    密码:<input type="text" id="pwd" onblur="a2()"/>
    <span id="pwdInfo"></span>
</p>
</body>
</html>

3、拦截器

体验拦截器

新建一个SpringMVC的空项目。
编写MyInterceptor

package interceptor;



import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MyInterceptor implements HandlerInterceptor {
    
    

    //在请求处理的方法之前执行
    //如果返回true执行下一个拦截器
    //如果返回false就不执行下一个拦截器
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
    
    
        System.out.println("------------处理前------------");
        return true;
    }

    //在请求处理方法执行之后执行
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
    
    
        System.out.println("------------处理后------------");
    }

    //在dispatcherServlet处理后执行,做清理工作.
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
    
    
        System.out.println("------------清理------------");
    }
}

配置applicationContext.xml

    &lt;!&ndash;关于拦截器的配置&ndash;&gt;
    <mvc:interceptors>
        <mvc:interceptor>
            &lt;!&ndash;/** 包括路径及其子路径&ndash;&gt;
            &lt;!&ndash;/admin/* 拦截的是/admin/add等等这种 , /admin/add/user不会被拦截&ndash;&gt;
            &lt;!&ndash;/admin/** 拦截的是/admin/下的所有&ndash;&gt;
            <mvc:mapping path="/**"/>
            &lt;!&ndash;bean配置的就是拦截器&ndash;&gt;
            <bean class="interceptor.MyInterceptor"/>
        </mvc:interceptor>
    </mvc:interceptors>

编写一个Controller

package controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpSession;

@Controller
@RequestMapping("/user")
public class LoginController {
    
    
    @RequestMapping("/main")
    public String main() {
    
    
        return "main";
    }

    @RequestMapping("/goLogin")
    public String login() {
    
    
        return "login";
    }

    @RequestMapping("/login")
    public String login(HttpSession session, String username, String password, Model model) {
    
    

        //把用户的信息存在session中
        session.setAttribute("userLoginInfo", username);
        model.addAttribute("password", password);
        model.addAttribute("username", username);
        return "main";
    }

    @RequestMapping("/goOut")
    public String goOut(HttpSession session) {
    
    
        session.removeAttribute("userLoginInfo");
        return "login";
    }
}

前端 index.jsp

<a href="${pageContext.request.contextPath}/interceptor">拦截器测试</a>

验证用户是否登录 (认证用户)

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>登录</title>
</head>
<body>
<%--在web-inf下面的所有页面或者资源，只能通过controller或者Servlet进行访问--%>
<h1>登录页面</h1>

<form action="${pageContext.request.contextPath}/user/login" method="post">
    用户名：<input type="text" name="username">
    密码：<input type="text" name="password">
    <input type="submit" value="提交">
</form>
</body>
</html>

编写一个Controller

@Controller
@RequestMapping("/user")
public class LoginController {
    
    
    @RequestMapping("/main")
    public String main() {
    
    
        return "main";
    }

    @RequestMapping("/goLogin")
    public String login() {
    
    
        return "login";
    }
    @RequestMapping("/login")
    public String login(HttpSession session, String username, String password, Model model) {
    
    

        //把用户的信息存在session中
        session.setAttribute("userLoginInfo",username);
        model.addAttribute("password",password);
        model.addAttribute("username",username);
        return "main";
    }

    @RequestMapping("/goOut")
    public String goOut(HttpSession sessionl) {
    
    
        sessionl.removeAttribute("userLoginInfo");
        return "login";
    }
}

main.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>首页</title>
</head>
<body>
<h1>首页</h1>
<span>${
    
    password}</span>
<span>${
    
    username}</span>

<p>
    <a href="${pageContext.request.contextPath}/user/goOut">注销</a>
</p>

</body>
</html>

index

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
  <title>index</title>
</head>
<body>
<h1><a href="${pageContext.request.contextPath}/user/goLogin">登录页面</a></h1>
<h1><a href="${pageContext.request.contextPath}/user/main">首页</a></h1>

</body>
</html>

编写用户登录拦截器

package interceptor;

import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class LoginInterceptor implements HandlerInterceptor {
    
    
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    
    
        HttpSession session = request.getSession();
        //放行:判断什么情况下登录

        //登录页面也会放行
        if (request.getRequestURI().contains("goLogin")) {
    
    
            return true;
        }
        if (request.getRequestURI().contains("login")) {
    
    
            return true;
        }
        if (session.getAttribute("userLoginInfo") != null) {
    
    
            return true;
        }
        //判断什么情况下没有登录
        request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request,response);
        return false;
    }
}

Springmvc的配置文件中注册拦截器

<!--关于拦截器的配置-->
<mvc:interceptors>
   <mvc:interceptor>
       <mvc:mapping path="/**"/>
       <bean id="loginInterceptor" class="com.kuang.interceptor.LoginInterceptor"/>
   </mvc:interceptor>
</mvc:interceptors>

4、文件上传下载

文件下载

创建一个空白的SpringMVC框架
配置spring的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"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       https://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/mvc
       https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!-- 自动扫描包，让指定包下的注解生效,由IOC容器统一管理 -->
    <context:component-scan base-package="controller"/>
    <!-- 让Spring MVC不处理静态资源 -->
    <mvc:default-servlet-handler/>
    <!--
    支持mvc注解驱动
        在spring中一般采用@RequestMapping注解来完成映射关系
        要想使@RequestMapping注解生效
        必须向上下文中注册DefaultAnnotationHandlerMapping
        和一个AnnotationMethodHandlerAdapter实例
        这两个实例分别在类级别和方法级别处理。
        而annotation-driven配置帮助我们自动完成上述两个实例的注入。
     -->
    <mvc:annotation-driven/>
    <!--视图解析器:DispatcherServlet给他的ModelAndView-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver">
        <!--前缀-->
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <!--后缀-->
        <property name="suffix" value=".jsp"/>
    </bean>


    <!--文件上传配置-->
    <bean id="multipartResolver"  class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!-- 请求的编码格式，必须和jSP的pageEncoding属性一致，以便正确读取表单的内容，默认为ISO-8859-1 -->
        <property name="defaultEncoding" value="utf-8"/>
        <!-- 上传文件大小上限，单位为字节（10485760=10M） -->
        <property name="maxUploadSize" value="10485760"/>
        <property name="maxInMemorySize" value="40960"/>
    </bean>

</beans>

配置web.xml

<!DOCTYPE web-app PUBLIC
        "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
        "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>

  <!--1.注册servlet-->
  <servlet>
    <servlet-name>SpringMVC</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!--通过初始化参数指定SpringMVC配置文件的位置，进行关联-->
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springmvc-servlet.xml</param-value>
    </init-param>
    <!-- 启动顺序，数字越小，启动越早 -->
    <load-on-startup>1</load-on-startup>
  </servlet>

  <!--所有请求都会被springmvc拦截 -->
  <servlet-mapping>
    <servlet-name>SpringMVC</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
</web-app>

再webapp下面创建静态资源如
在这里插入图片描述编写FileController

 @RequestMapping(value="/download")
    public String downloads(HttpServletResponse response , HttpServletRequest request) throws Exception{
    
    
        //要下载的图片地址
        String  path = request.getServletContext().getRealPath("/static");
        String  fileName = "12.txt";

        //1、设置response 响应头
        response.reset(); //设置页面不缓存,清空buffer
        response.setCharacterEncoding("UTF-8"); //字符编码
        response.setContentType("multipart/form-data"); //二进制传输数据
        //设置响应头
        response.setHeader("Content-Disposition",
                "attachment;fileName="+ URLEncoder.encode(fileName, "UTF-8"));

        File file = new File(path,fileName);
        //2、 读取文件--输入流
        InputStream input=new FileInputStream(file);
        //3、 写出文件--输出流
        OutputStream out = response.getOutputStream();

        byte[] buff =new byte[1024];
        int index=0;
        //4、执行 写出操作
        while((index= input.read(buff))!= -1){
    
    
            out.write(buff, 0, index);
            out.flush();
        }
        out.close();
        input.close();
        return null;
    }

启动Tomcat测试localhost:8080/download
在这里插入图片描述

文件上传

导入依赖

<!--文件上传-->
<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.3.3</version>
</dependency>
<!--servlet-api导入高版本的-->
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>4.0.1</version>
</dependency>

配置Spring配置文件

<!--文件上传配置-->
<bean id="multipartResolver"  class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <!-- 请求的编码格式，必须和jSP的pageEncoding属性一致，以便正确读取表单的内容，默认为ISO-8859-1 -->
    <property name="defaultEncoding" value="utf-8"/>
    <!-- 上传文件大小上限，单位为字节（10485760=10M） -->
    <property name="maxUploadSize" value="10485760"/>
    <property name="maxInMemorySize" value="40960"/>
</bean>

前端页面

<form action="/upload" enctype="multipart/form-data" method="post">
  <input type="file" name="file"/>
  <input type="submit" value="upload">
</form>

编写Controller

package controller;
 
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.commons.CommonsMultipartFile;
 
import javax.servlet.http.HttpServletRequest;
import java.io.*;
 
@Controller
public class FileController {
    
    
    //@RequestParam("file") 将name=file控件得到的文件封装成CommonsMultipartFile 对象
    //批量上传CommonsMultipartFile则为数组即可
    @RequestMapping("/upload")
    public String fileUpload(@RequestParam("file") CommonsMultipartFile file , HttpServletRequest request) throws IOException {
    
    
 
        //获取文件名 : file.getOriginalFilename();
        String uploadFileName = file.getOriginalFilename();
 
        //如果文件名为空，直接回到首页！
        if ("".equals(uploadFileName)){
    
    
            return "redirect:/index.jsp";
        }
        System.out.println("上传文件名 : "+uploadFileName);
 
        //上传路径保存设置
        String path = request.getServletContext().getRealPath("/upload");
        //如果路径不存在，创建一个
        File realPath = new File(path);
        if (!realPath.exists()){
    
    
            realPath.mkdir();
        }
        System.out.println("上传文件保存地址："+realPath);
 
        InputStream is = file.getInputStream(); //文件输入流
        OutputStream os = new FileOutputStream(new File(realPath,uploadFileName)); //文件输出流
 
        //读取写出
        int len=0;
        byte[] buffer = new byte[1024];
        while ((len=is.read(buffer))!=-1){
    
    
            os.write(buffer,0,len);
            os.flush();
        }
        os.close();
        is.close();
        return "redirect:/index.jsp";
    }
}

Controller

/*
 * 采用file.Transto 来保存上传的文件
 */
@RequestMapping("/upload2")
public String  fileUpload2(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException {
    
    
 
    //上传路径保存设置
    String path = request.getServletContext().getRealPath("/upload");
    File realPath = new File(path);
    if (!realPath.exists()){
    
    
        realPath.mkdir();
    }
    //上传文件地址
    System.out.println("上传文件保存地址："+realPath);
 
    //通过CommonsMultipartFile的方法直接写文件（注意这个时候）
    file.transferTo(new File(realPath +"/"+ file.getOriginalFilename()));
 
    return "redirect:/index.jsp";
}