SpringMVC
SpringMVC
-
- 1. SpringMVC简介
-
- 1.1 概念
- 1.2 SpringMVC执行原理
- 2. 第一个SpringMVC
-
- 2.1 不使用注解
- 2.2 使用注解
- 3. Controller & RestFul
-
- 3.1 RestFul
- 3.2 转发与重定向
- 3.3 接收参数与数据回显
- 3.4 乱码问题
- 4. JSON
-
- 4.1 初识JSON
- 4.2 Jackson-Databind
- 4.3 FastJson
- 5. SSM整合
-
- 5.1 环境准备
- 5.2 项目结构
- 5.3 整合Mybatis
- 5.4 整合Spring
- 5.5 整合SpringMVC
- 5.6 dao层
- 5.7 service层
- 5.8 controller层
- 5.9 前端页面
- 6. AJax
-
- 6.1 概念
- 6.2 通过JQ发送Ajax
- 7. 拦截器
-
- 7.1 概念
- 7.2 自定义拦截器
- 7.3 登录验证
- 8. 文件上传&下载
-
- 8.1 上传
- 8.2 下载
感谢狂神的分享：B站视频地址
SpringMVC：官网地址
参考博客：地址
1. SpringMVC简介
1.1 概念
- MVC：是模型(Model)、视图(View)、控制器(Controller)的简写，是一种软件设计规范。代码实现上：模型（service、dao）控制器（controller）视图（jsp）。
- 概念：SpringMVC 是Spring框架中的一个分支，是基于Java实现MVC的轻量级Web框架
- 核心：Spring的web框架围绕DispatcherServlet [ 调度Servlet ] 设计的
- 特点：轻量级,简单易学；高效,基于请求响应的mvc框架；与spring兼容性好,无缝结合；约定大于配置；功能强大:RESTful,数据验证,格式化,本地化,主题
1.2 SpringMVC执行原理
- DispatcherServlet表示前置控制器，是整个SpringMVC的控制中心。用户发出请求，DispatcherServlet接收请求并拦截请求。
- 假设url为 : http://localhost:8080/SpringMVC/hello，拆成三个部分：
- 服务器域名：http://localhost:8080
- 服务器上的站点：SpringMVC
- 控制器：hello
- HandlerMapping（处理器映射器）。DispatcherServlet调用HandlerMapping，HandlerMapping根据请求url查找Handler。
- HandlerExecution，表示具体的 Handler，其主要作用是根据url查找控制器，如上url被查找控制器为：hello。
- HandlerExecution将解析后的信息传递给DispatcherServlet，如解析控制器映射等。
- HandlerAdapter（处理器适配器），其按照特定的规则去执行Handler。
- Handler 让具体的 Controller 执行
- Controller 将具体的执行信息返回给HandlerAdapter，如ModelAndView。
- HandlerAdapter 将视图逻辑名或模型传递给 DispatcherServlet。
- DispatcherServlet调用ViewResolver（视图解析器）来解析HandlerAdapter传递的逻辑视图名
DispatchServlet是接收前端的所有路径的请求，接收到之后根据路径去找对应的controller方法，因为每一个controller方法都被用@RequestMapping注解给予对应的路径 - ViewResolver将解析的逻辑视图名传给DispatcherServlet
- DispatcherServlet根据 ViewResolver 解析的视图结果，调用具体的视图
1-4相当于原来servletservlet-mapping，5-8，原来servlet，10-12就是servlet 请求转发和重定向
2. 第一个SpringMVC
2.1 不使用注解
创建一个maven项目，导入jar包依赖
<dependencies>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<version>4.11version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webmvcartifactId>
<version>5.3.20version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>servlet-apiartifactId>
<version>2.5version>
dependency>
<dependency>
<groupId>javax.servlet.jspgroupId>
<artifactId>jsp-apiartifactId>
<version>2.1version>
dependency>
<dependency>
<groupId>javax.servlet.jsp.jstlgroupId>
<artifactId>jstl-apiartifactId>
<version>1.2version>
dependency>
dependencies>
项目结构如下
web.xml中注册 DispatcherServlet
<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">
<servlet>
<servlet-name>SpringMvcservlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
<init-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:spring_servlet.xmlparam-value>
init-param>
servlet>
<servlet-mapping>
<servlet-name>SpringMvcservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
web-app>
配置SpringMvc核心配置文件
<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:p="http://www.springframework.org/schema/p"
xmlns:c="http://www.springframework.org/schema/c"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://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/aop
https://www.springframework.org/schema/aop/spring-aop.xsd">
<bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/>
<bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
bean>
<bean name="/hello" class="com.kuang.controller.HelloController"/>
beans>
自定义类，实现Controller接口
//创建一个类，实现Controller接口
public class HelloController implements Controller {
@Override
public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
//创建 ModelAndView 对象
ModelAndView modelAndView = new ModelAndView();
//在对象中添加属性值
modelAndView.addObject("msg","hello,Spring MVC !!!");
//设置要跳转的视图。
modelAndView.setViewName("hello"); //结合 prefix 、suffix ，会映射成路径： WEB-INF/jsp/hello.jsp
return modelAndView;
}
}
前端JSP页面
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Titletitle>
head>
<body>
${msg}
body>
html>
注：如果项目无法正常启动，查看 project structure --> artifacts右侧 -->Output Layout 下 WEB-INF是否导入相关jar包
SpringMVC底层工作原理：
2.2 使用注解
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_4_0.xsd"
version="4.0">
<servlet>
<servlet-name>springMVCservlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
<init-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:springMVC.xmlparam-value>
init-param>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>springMVCservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
web-app>
springMVC.xml
- 省略了 handlerMapping、HandlerAdapter的手动配置，由annotation-driven 完成
- 配置注解扫描指定的包
<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
https://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">
<context:component-scan base-package="com.kuang.controller"/>
<mvc:default-servlet-handler/>
<mvc:annotation-driven/>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver">
<property name="prefix" value="WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
bean>
beans>
controller
@Controller
public class HelloController {
/*添加方法的访问路径
如果方法加上 @ResponseBody，或者类用@RestController标识
则方法返回字符串，不再被视图解析器处理
*/
@RequestMapping("/hello")
public String hello(Model model){
//封装返回数据
model.addAttribute("msg","hello,annotation method!!!");
return "test"; //被视图解析器处理，拼装前、后缀形成路径
}
}
3. Controller & RestFul
3.1 RestFul
优点：
- 安全：看不出源代码的参数也意义
- 地址复用：使得 get 和 post 访问相同的URL，框架自动进行类型转换
- 高效：支持缓存
缺点：
- 不像原生URL见名只意，URL理解不直观
实现方式
- 注解：
@GetMapping("/addRest/{a}/{b}")+ 参数@PathVariable int a, @PathVariable int b
url地址：http://localhost:8080/xxx/addRest/1/2 - 注解：
@PostMapping("/addRest/{a}/{b}")+ 参数@PathVariable int a, @PathVariable int b
使用Post提交url地址：http://localhost:8080/xxx/addRest/1/2
@Controller
public class RestFulController {
/**
* 原生的url：http://localhost:8080/xxx/add?a=1&b=1
*/
@RequestMapping("/add")
public String getAdd1(int a, int b, Model model) {
int result = a + b;
model.addAttribute("add", "原生的url：结果为" + result);
return "add";
}
/**
* RestFul方式一：method = get
* RequestMapping("/addRest/{a}/{b}" method=requestMethod.GET) = @GetMapping()
* http://localhost:8080/springmvc_04/addRest/1/1
*/
@GetMapping("/addRest/{a}/{b}")
public String getAdd2(@PathVariable int a, @PathVariable int b, Model model) {
int result = a + b;
model.addAttribute("add", "Rest的url：结果为" + result);
return "addRest";
}
/**
* 复用相同的url
* RestFul方式二：method=post，使用RestFul的话，请求的url和GET就一样了
*/
@PostMapping("/addRest/{a}/{b}")
public String getAdd3(@PathVariable int a, @PathVariable int b, Model model) {
int result = a + b;
model.addAttribute("add", "Rest的url：结果为" + result);
return "addRest";
}
}
3.2 转发与重定向
- 可以使用原生的request转发或者response重定向
- 推荐使用SpringMvc的
return “forward:xxx”/"redirect:xxx"
@Controller
public class ModelTest1 {
//原生的转发：返回值是void，没有经过视图解析器；原生的重定向同样如此，都不走视图解析器，直接重定向
@RequestMapping("/test1")
public void test1(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String id = request.getSession().getId();
System.out.println(id);
request.getRequestDispatcher("index.jsp").forward(request,response);
}
//SpringMvc转发：测试结果是不走视图解析器，url没变是转发
@RequestMapping("/test2")
public String test2(Model model) {
model.addAttribute("demo1","这是test2中的Spring转发");
return "forward:/WEB-INF/jsp/demo1.jsp";
}
//SpringMvc重定向：测试结果是不走视图解析器
@RequestMapping("/test3")
public String test3() {
System.out.println("跳转回首页index.jsp");
return "redirect:index.jsp";
}
}
3.3 接收参数与数据回显
- 前端提交的name和后端映射器接受的形参名一样，则直接接受
- 前端提交的name和后端映射器接受的形参名不用一样，在形参前
@RequestParam("xxx")更改名称一致 - 如果后端参数封装成一个pojo，前端传过来的name会自动pojo中的成员属性，不匹配的属性=null/0
@Controller
public class UserController {
/** http://localhost:8080/springmvc_04/t1?id=1&name=abc&age=18
* @param user SpringMvc 会自动封装数据到参数里的pojo，不匹配的属性=null/0
*/
@GetMapping("/t1")
public String getUser(User user){
System.out.println(user);
return "test1";
}
}
3.4 乱码问题
- 方法一：web.xml里面配置的SpringMvc自带的过滤器
CharacterEncodingFilter，/*
<filter>
<filter-name>encodefilter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilterfilter-class>
<init-param>
<param-name>encodingparam-name>
<param-value>utf-8param-value>
init-param>
filter>
<filter-mapping>
<filter-name>encodefilter-name>
<url-pattern>/*url-pattern>
filter-mapping>
- 方法二：一劳永逸，但需要重启Tomcat服务器，修改Tomcat里面的server.xml配置文件：URIEncoding = “UTF-8”
<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443"
URIEncoding = "UTF-8"/>
4. JSON
4.1 初识JSON
JSON（JavaScript Object Notation, JS对象标记）是一种轻量级的数据交换格式。它基于 ECMAScript的一个子集，采用完全独立于编程语言的文本格式来存储和表示数据。简洁和清晰的层次结构使得 JSON 成为理想的数据交换语言。 易于人阅读和编写，同时也易于机器解析和生成，并有效地提升网络传输效率。
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>jsontitle>
<script type="text/javascript">
//user是一个js对象
var user = {
name: "张三",
age: 18,
sex: "男"
};
//后端传的json其实是一个字符串，前端将后端传的json转换成js对象渲染在页面上
//jsonUser:模拟后端传的json数据
//js转换成json
var jsonUser = JSON.stringify(user);
console.log(jsonUser);
//jsUser：js是一个对象
//json转换成js
var jsUser = JSON.parse(jsonUser);
console.log(jsUser)
script>
head>
html>
4.2 Jackson-Databind
1. 导入依赖：
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-databindartifactId>
<version>xxxversion>
dependency>
- json=一个字符串，所以会有中文乱码问题，需要在springmvc.xml配置
<mvc:annotation-driven>
<mvc:message-converters register-defaults="true">
<bean class="org.springframework.http.converter.StringHttpMessageConverter">
<constructor-arg value="UTF-8"/>
bean>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="objectMapper">
<bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
<property name="failOnEmptyBeans" value="false"/>
bean>
property>
bean>
mvc:message-converters>
mvc:annotation-driven>
2. 编写Controller
@RestControoler：该类下所有方法不走视图解析器，返回一个json数据@ResponseBody：该方法不走视图解析器，返回一个json数据
@RestController
public class UserController {
//Json返回一个对象
@RequestMapping("/t1")
public String json1() throws JsonProcessingException {
User user = new User(1, "张三", 20);
ObjectMapper jacksonMapper = new ObjectMapper();
String str_user = jacksonMapper.writeValueAsString(user);
//str_user有中文乱码问题，springMvc可以统一配置
return str_user;
}
}
4.3 FastJson
1. 导包
<dependency>
<groupId>com.alibabagroupId>
<artifactId>fastjsonartifactId>
<version>xxxversion>
dependency>
2. 介绍
- JSONObject 代表JSON对象
JSONObject实现了Map接口，对应的是json对象，通过各种形式的get()方法可以获取对象中的数据，使用诸如size()，isEmpty()方法获取 "键：值"的个数或判断是否为空。本质是通过实现Map接口，病调用其中的方法完成的。 - JSONArray 代表JSON数组
内部是List接口中的方法，完成操作的 - JSON 代表 JSONObject与JSONArray的转化
主要实现 json对象、json数组、Javabean对象、json字符串之间的相互转化
5. SSM整合
5.1 环境准备
数据库：
CREATE TABLE `books` (
`bookId` int(10) NOT NULL AUTO_INCREMENT COMMENT '书id',
`bookName` varchar(100) NOT NULL COMMENT '书名',
`bookCounts` int(11) NOT NULL COMMENT '数量',
`detail` varchar(200) NOT NULL COMMENT '描述',
KEY `bookId` (`bookId`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0modelVersion>
<groupId>com.kuanggroupId>
<artifactId>SpringMVCartifactId>
<packaging>pompackaging>
<version>1.0-SNAPSHOTversion>
<modules>
<module>spring_jsonmodule>
<module>spring_ssmmodule>
modules>
<properties>
<maven.compiler.source>8maven.compiler.source>
<maven.compiler.target>8maven.compiler.target>
properties>
<dependencies>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<version>4.13.2version>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>8.0.29version>
dependency>
<dependency>
<groupId>com.mchangegroupId>
<artifactId>c3p0artifactId>
<version>0.9.5.2version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>servlet-apiartifactId>
<version>2.5version>
dependency>
<dependency>
<groupId>javax.servlet.jspgroupId>
<artifactId>jsp-apiartifactId>
<version>2.2version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>jstlartifactId>
<version>1.2version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatisartifactId>
<version>3.5.10version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatis-springartifactId>
<version>2.0.7version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webmvcartifactId>
<version>5.3.21version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-jdbcartifactId>
<version>5.3.21version>
dependency>
dependencies>
<build>
<resources>
<resource>
<directory>src/main/resourcesdirectory>
<includes>
<include>**/*.propertiesinclude>
<include>**/*.xmlinclude>
includes>
<filtering>truefiltering>
resource>
<resource>
<directory>src/main/javadirectory>
<includes>
<include>**/*.propertiesinclude>
<include>**/*.xmlinclude>
includes>
<filtering>truefiltering>
resource>
resources>
build>
project>
5.2 项目结构
5.3 整合Mybatis
mybatis-config.xml配置如下（数据库连接交给 spring_dao.xml 管理）：
DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<settings>
<setting name="logImpl" value="STDOUT_LOGGING"/>
settings>
<typeAliases>
<package name="com.kuang.pojo"/>
typeAliases>
<mappers>
<mapper class="com.kuang.dao.BooksMapper">mapper>
mappers>
configuration>
jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/stu?useSSL=false&useUnicode=true&characterEncoding=utf-8
jdbc.username=root
jdbc.password=123456
5.4 整合Spring
分成spring_dao.xml，spring_service.xml，spring_mvc.xml 三层整合，然后通过Spring核心配置文件，将三部分合并到一起
Spring_dao.xml主要配置mybatis-spring.jar中的信息
<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
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<context:property-placeholder location="classpath:jdbc.properties"/>
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"/>
<property name="jdbcUrl" value="${jdbc.url}"/>
<property name="user" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
<property name="maxPoolSize" value="30"/>
<property name="minPoolSize" value="10"/>
<property name="autoCommitOnClose" value="false"/>
<property name="checkoutTimeout" value="10000"/>
<property name="acquireRetryAttempts" value="2"/>
bean>
<bean name="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="configLocation" value="classpath:mybatis-config.xml"/>
bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactoryBean"/>
<property name="basePackage" value="com.kuang.dao"/>
bean>
beans>
spring_service.xml
<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
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<context:component-scan base-package="com.kuang.service"/>
<bean id="booksServiceImpl" class="com.kuang.service.BooksServiceImpl">
<property name="booksMapper" ref="booksMapper"/>
bean>
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
bean>
beans>
通过applicationContext.xml，合并spring的几个配置文件
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">
<import resource="spring_dao.xml"/>
<import resource="spring_service.xml"/>
<import resource="spring_mvc.xml"/>
beans>
5.5 整合SpringMVC
添加web项目支持，并配置web.xml
web.xml配置如下
<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">
<servlet>
<servlet-name>SpringMVCservlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
<init-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:applicationContext.xmlparam-value>
init-param>
servlet>
<servlet-mapping>
<servlet-name>SpringMVCservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
<filter>
<filter-name>encodingFilterfilter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilterfilter-class>
<init-param>
<param-name>encodingparam-name>
<param-value>utf-8param-value>
init-param>
filter>
<filter-mapping>
<filter-name>encodingFilterfilter-name>
<url-pattern>/*url-pattern>
filter-mapping>
web-app>
spring_mvc.xml配置如下：
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/mvc
https://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<mvc:annotation-driven/>
<mvc:default-servlet-handler/>
<context:component-scan base-package="com.kuang.controller"/>
<bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
bean>
beans>
5.6 dao层
dao层有 BooksMapper.java、 BooksMapper.xml，内容如下：
public interface BooksMapper {
//增加一本书
int addBook(Books books);
//删除一本书
int deleteBookById(@Param("bookId") int id);
//修改一本书
int updateBook(Books books);
//查询一本书根据id
Books queryBookById(@Param("bookId")int id);
//查询全部书
List<Books> queryAllBook();
Books queryBookByName(@Param("bookName") String bookName);
}
DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.kuang.dao.BooksMapper">
<insert id="addBook" parameterType="Books">
insert into ssmbuild.books(bookName, bookCounts, detail)
values (#{bookName},#{bookCounts},#{detail});
insert>
<delete id="deleteBookById" parameterType="int">
delete from ssmbuild.books where bookId = #{bookId}
delete>
<update id="updateBook" parameterType="Books">
update ssmbuild.books set
bookName=#{bookName},
bookCounts=#{bookCounts},
detail=#{detail}
where bookId=#{bookId};
update>
<select id="queryBookById" parameterType="int" resultType="Books">
select * from ssmbuild.books where bookId = #{bookId};
select>
<select id="queryAllBook" resultType="Books">
select * from ssmbuild.books;
select>
<select id="queryBookByName" parameterType="String" resultType="Books">
select * from ssmbuild.books where bookName=#{bookName}
select>
mapper>
5.7 service层
public interface BooksService {
//增加一本书
int addBook(Books books);
//删除一本书
int deleteBookById(int id);
//修改一本书
int updateBook(Books books);
//查询一本书根据id
Books queryBookById(int id);
//查询全部书
List<Books> queryAllBook();
Books queryBookByName(String bookName);
}
public class BooksServiceImpl implements BooksService {
//在spring中，注入Dao层
private BooksMapper booksMapper;
public void setBooksMapper(BooksMapper booksMapper) {
this.booksMapper = booksMapper;
}
@Override
public int addBook(Books books) {
return booksMapper.addBook(books);
}
@Override
public int deleteBookById(int id) {
return booksMapper.deleteBookById(id);
}
@Override
public int updateBook(Books books) {
return booksMapper.updateBook(books);
}
@Override
public Books queryBookById(int id) {
return booksMapper.queryBookById(id);
}
@Override
public List<Books> queryAllBook() {
return booksMapper.queryAllBook();
}
@Override
public Books queryBookByName(String bookName) {
return booksMapper.queryBookByName(bookName);
}
}
5.8 controller层
@Controller
@RequestMapping("book")
public class BooksController {
@Autowired
@Qualifier("booksServiceImpl")
private BooksService booksService;
@RequestMapping("allBook")
public String allBook(Model model){
List<Books> books = booksService.queryAllBook();
model.addAttribute("list", books);
return "allBook";
}
//跳转到增加书籍页面
@RequestMapping("/toAddBook")
public String toAddBook() {
return "addBook";
}
//添加书籍，成功后跳转至所有书籍页面
@RequestMapping("/addBook")
public String addBook(Books books) {
int result = booksService.addBook(books);
if (result > 0) {
System.out.println("添加书籍成功");
}
return "redirect:/book/allBook";
}
@RequestMapping("/toUpdateBook")
public String toUpdate(int bookId, Model model) {
Books books = booksService.queryBookById(bookId);
model.addAttribute("book", books);
return "updateBook";
}
//没有提交事务操作，更新会失败
@RequestMapping("/updateBook")
public String updateBook(Books books) {
int result = booksService.updateBook(books);
if (result > 0) {
System.out.println("修改书籍成功");
}
return "redirect:/book/allBook";
}
//删除书籍，回顾RestFul风格
@RequestMapping("/deleteBook/{bookId}")
public String deleteBook(@PathVariable("bookId") int bookId) {
int result = booksService.deleteBookById(bookId);
if (result > 0) {
System.out.println("删除书籍成功");
}
return "redirect:/book/allBook";
}
@RequestMapping("/queryBook")
public String queryBook(String queryBookName, Model model) {
Books books = booksService.queryBookByName(queryBookName);
//复用，这样就显示一个
List<Books> list = new ArrayList<>();
list.add(books);
if (books == null) {
list= booksService.queryAllBook();
model.addAttribute("errMsg","未查任何书籍");
}
model.addAttribute("list", list);
return "allBook";
}
}
5.9 前端页面
allBook.jsp
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>所有书籍title>
<%--BootStrap美化界面--%>
<link href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
head>
<body>
<div class="container">
<div class="row clearfix">
<%--屏幕分成12列--%>
<div class="col-md-12 column">
<div class="page-header">
<h1>
<small> 书籍列表——————————显示所有书籍small>
h1>
div>
div>
<div class="row">
<div class="col-md-4 column">
<a class="btn btn-primary" href="${pageContext.request.contextPath}/book/toAddBook">新增书籍a>
<a class="btn btn-primary" href="${pageContext.request.contextPath}/book/allBook">显示全部书籍a>
div>
<div class="col-md-4 column">div>
<div class="col-md-8 column">
<form action="${pageContext.request.contextPath}/book/queryBook" method="post" style="float: right">
<%--前端未传任何信息，就显示错误提示信息：未查任何书籍--%>
<span style="color: red;font-weight: bold">${errMsg}span>
<%--class="form-inline"保证在同一行--%>
<input type="text" name="queryBookName" class="form-inline" placeholder="请输入要查询的书籍名称">
<input type="submit" value="查询" class="btn btn-primary">
form>
div>
div>
div>
<div class="row clearfix">
<div class="col-md-12 column">
<table class="table table-hover table-striped">
<thead>
<tr>
<th>书籍编号th>
<th>书籍名称th>
<th>书籍数量th>
<th>书籍详情th>
<th>操作th>
tr>
thead>
<%--书籍从数据库中查询出来，从这个list中遍历出来，foreach--%>
<tbody>
<c:forEach var="book" items="${list}">
<tr>
<td>${book.bookId}td>
<td>${book.bookName}td>
<td>${book.bookCounts}td>
<td>${book.detail}td>
<td>
<a href="${pageContext.request.contextPath}/book/toUpdateBook?bookId=${book.bookId}">修改a>
|
<a href="${pageContext.request.contextPath}/book/deleteBook/${book.bookId}">删除a>
td>
tr>
c:forEach>
tbody>
table>
div>
div>
div>
body>
html>
addBook.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>添加书籍title>
<%--BootStrap美化界面--%>
<link href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
head>
<body>
<div class="row clearfix">
<%--屏幕分成12列--%>
<div class="col-md-12 column">
<div class="page-header">
<h1>
<small>新增书籍small>
h1>
div>
div>
div>
<%--BootStrap官网拿"表单"数据 name属性保证pojo属性名称一致 required保证必须提交--%>
<form action="${pageContext.request.contextPath}/book/addBook" method="post">
<div class="form-group">
<label for="bName">书籍名称:label>
<input type="text" name="bookName" class="form-control" id="bName" required>
div>
<div class="form-group">
<label for="bCount">书籍数量：label>
<input type="text" name="bookCounts" class="form-control" id="bCount" required>
div>
<div class="form-group">
<label for="bDesc">书籍描述：label>
<input type="text" name="detail" class="form-control" id="bDesc" required>
div>
<div class="form-group">
<input type="submit" class="form-control" value="添加">
div>
form>
body>
html>
updateBook.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>修改书籍title>
<title>Titletitle>
<%--BootStrap美化界面--%>
<link href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
head>
<body>
<div class="row clearfix">
<%--屏幕分成12列--%>
<div class="col-md-12 column">
<div class="page-header">
<h1>
<small>修改书籍small>
h1>
div>
div>
div>
<%--BootStrap官网拿"表单"数据 name属性保证pojo属性名称一致 required保证必须提交--%>
<form action="${pageContext.request.contextPath}/book/updateBook" method="post">
<%--提交失败：没有回显：问题：
1. 事务没有提交
2. sql执行失败，没有提交BookId，需要前端的隐藏域
--%>
<%--添加bookId的隐藏域--%>
<input type="hidden" name="BookId" value="${book.bookId}">
<div class="form-group">
<label for="bName">书籍名称:label>
<input type="text" name="bookName" class="form-control" id="bName" value="${book.bookName}" required>
div>
<div class="form-group">
<label for="bCount">书籍数量：label>
<input type="text" name="bookCounts" class="form-control" id="bCount" value="${book.bookCounts}"required>
div>
<div class="form-group">
<label for="bDesc">书籍描述：label>
<input type="text" name="detail" class="form-control" id="bDesc" value="${book.detail}" required>
div>
<div class="form-group">
<input type="submit" class="form-control" value="修改">
div>
form>
body>
html>
6. AJax
6.1 概念
Ajax：Asynchronous Javascript And XML（异步JavaScript和XML），一个异步无刷新请求，无需更新整个页面就异步加载一些数据。
使用iframe，模拟异步请求
DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>模拟Ajax异步请求title>
<script>
function go() {
var url = document.getElementById("url").value;
document.getElementById("iframe1").src = url;
}
script>
head>
<body>
<div>
<p>请输入地址：p>
<p>
<input type="text" id="url">
<input type="button" id="button" value="提交" onclick="go()">
p>
div>
<div>
<iframe id="iframe1" style="width:100%;height: 500px">
iframe>
div>
body>
html>
6.2 通过JQ发送Ajax
初试Ajax
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title$title>
<%--加载动态的JQ资源--%>
<script src="https://code.jquery.com/jquery-3.4.1.js">script>
<script>
/*
AJax参数：
url：后端接受的地址
data：后端接受到的请求参数，json数据格式=前后端分离时候，后端传的数据便于前端接受就是json数据
success:后端接受成功返回的函数
error:后端失败接受返回的函数
*/
function username() {
$.post({
url: "${pageContext.request.contextPath}/a1",
data: {"name": $("#username").val()},
success: function (data, status) {
console.log("data:" + data);
console.log("status:" + status);
}
})
}
script>
head>
<body>
<%--
实现Ajax异步请求
1 绑定单击事件
2 单击事件函数使用Jq：$.post({})
--%>
用户名:<input type="text" id="username" onclick="username()">
body>
html>
异步加载
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Ajaxtitle>
<script src="https://code.jquery.com/jquery-3.4.1.js">script>
<script>
/*页面加载完,触发函数*/
$(function () {
/*绑定btn单击事件*/
$("#btn").click(function () {
/*JQ使用Ajax异步请求*/
$.post("${pageContext.request.contextPath}/a2", function (data) {
// data接受返回的值
//console.log(data);
var html = "";
for (let i = 0; i < data.length; i++) {
html += "" +
"" + data[i].name + " " +
"" + data[i].age + " " +
"" + data[i].sex + " " +
+""
}
$("#content").html(html);
});
});
})
script>
head>
<body>
<input type="button" id="btn" value="加载数据">
<table>
<tr>
<td>姓名td>
<td>年龄td>
<td>性别td>
tr>
<tbody id="content">
tbody>
table>
body>
html>
登录验证
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>logintitle>
<script src="https://code.jquery.com/jquery-3.4.1.js">script>
<script>
function nameFun() {
$.post({
url: "${pageContext.request.contextPath}/a3",
data: {"name": $("#name").val()},
success: function (data) {
//console.log(data);
if (data.toString() === "用户名成功") {
$("#userInfo").css("color", "green");
} else {
$("#userInfo").css("color", "red");
}
$("#userInfo").html(data);
}
})
}
function passwordFun() {
$.post({
url: "${pageContext.request.contextPath}/a3",
data: {"password": $("#password").val()},
success: function (data) {
if (data.toString() === "密码正确") {
$("#userPasswordInfo").css("color", "green");
}else {
$("#userPasswordInfo").css("color", "red");
}
$("#userPasswordInfo").html(data);
}
})
}
script>
head>
<body>
<p>
用户名:<input type="text" id="name" onclick="nameFun()">
<%--span提示信息--%>
<span id="userInfo">span>
p>
<p>
用户密码:<input type="password" id="password" onclick="passwordFun()">
<span id="userPasswordInfo">span>
p>
body>
html>
7. 拦截器
7.1 概念
拦截器（Interceptor）基于反射机制（动态代理）实现，Struts、SpringMVC都有拦截器功能，不依赖Tomcat等容器，不能修改 Request 中的内容，用于验证信息（用户是否登录、权限验证、日志记录等
）
过滤器（Filter）与拦截器（Interceptor）都体现了AOP的思想，区别如下：
实现方式不同
Filter基于回调函数实现，依赖于Tomcat等容器，只能用在web项目中。而Interceptor是Spring的一个组件，不依赖于Tomcat等容器，也可以用在Application、Swing等容器中。
触发时机不同
Filter在请求进入容器之后，但进入Servlet容器之前进行预处理，请求结束是在Servlet处理完之后。
Interceptor在请求进入Servlet后，但进入Controller之前进行预处理，Controller中渲染了对应的视图之后请求结束。
拦截范围不同
Filter 几乎可以对所有进入容器的请求起作用
Interceptor 只对Controller中请求或static目录下的资源请求起作用
7.2 自定义拦截器
自定义拦截器，实现HandlerInterceptor接口：
public class MyInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
//return true：执行下一个拦截器
System.out.println("===========处理前,这里进行拦截处理=================");
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
System.out.println("===========处理后，通常进行日志管理=================");
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
System.out.println("===========清理中=================");
}
}
在Spring配置文件中注册：
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/**"/>
<bean class="com.ssl.config.MyInterceptor"/>
mvc:interceptor>
mvc:interceptors>
7.3 登录验证
拦截器
public class LoginInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
HttpSession session = request.getSession();
request.getRequestURL();
//URL: http://localhost:8080/springmvc_07_interceptor/user/main
System.out.println("URL:" + request.getRequestURL());
//URI: /springmvc_07_interceptor/user/main
System.out.println("URI:" + request.getRequestURI());
if (session.getAttribute("username") == null || session.getAttribute("password") == null) {
request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request, response);
} else if (session.getAttribute("username").equals("admin") && session.getAttribute("password").equals("123456")) {
return true;
}
if (request.getRequestURI().contains("login")) {
return true;
}
request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request, response);
return false;
}
}
控制层
@Controller
@RequestMapping("/user")
public class LoginController {
@RequestMapping("/main")
public String main() {
//沒登陸就不等進入首頁
return "main";
}
@RequestMapping("/gologin")
public String gologin() {
return "login";
}
@RequestMapping("/login")
public String login(String username, String password, HttpSession session, Model model) {
session.setAttribute("username", username);
session.setAttribute("password", password);
model.addAttribute("username", username);
return "main";
}
@RequestMapping("/outUser")
public String outUser(HttpSession session) {
session.removeAttribute("username");
session.removeAttribute("password");
return "main";
}
}
8. 文件上传&下载
8.1 上传
- 前端form添加enctype=“multipart/form-data”,method=“post”
<form enctype="multipart/form-data" method="post" action="">
form>
- 后端pom导包
<dependencies>
<dependency>
<groupId>commons-fileuploadgroupId>
<artifactId>commons-fileuploadartifactId>
<version>1.4version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>4.0.1version>
dependency>
dependencies>
- Spring自带的文件上传，application.xml配置
<!--4 文件上传配置-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="defaultEncoding" value="utf-8"/>
<!--最大上传大小：单位是1字节-->
<property name="maxUploadSize" value="10485760"/>
<property name="maxInMemorySize" value="40960"/>
</bean>
@RestController
public class FileController {
@RequestMapping("/upFile")
public String upFile(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException {
//设置文件保存路径
String path = request.getServletContext().getRealPath("/upload");
System.out.println("path:" + path);
File realPath = new File(path);
if (!realPath.exists()) {
realPath.mkdir();
}
System.out.println("上传的文件地址：" + realPath);
//CommonsMultipartFile的方法写文件，简化
file.transferTo(new File(realPath + "/" + file.getOriginalFilename()));
return "redirect:/index.jsp";
}
}
8.2 下载
- 方式一：写方法下载
@RequestMapping(value = "/download")
public String downLoad(HttpServletResponse response, HttpServletRequest request) throws IOException {
//手动设置，要下载的图片地址
String path = request.getServletContext().getRealPath("/upload");
String fileName = "1.png";
//设置响应头
response.reset();//设置页面不缓存，清空buffer
response.setCharacterEncoding("UTF-8");
response.setContentType("multipart/form-data");//二进制传输数据
response.setHeader("Content-Disposition", "attachment;fileName=" + URLEncoder.encode(fileName, "UTF-8"));
File file = new File(path, fileName);
//读取文件-输入流
InputStream input = new FileInputStream(file);
//写入文件-输出流
OutputStream out = response.getOutputStream();
byte[] buff = new byte[1024];
int index = 0;
while ((index = input.read(buff)) != -1) {
out.write(buff,0,index);
out.flush();
}
input.close();
out.close();
return "redirect:/index.jsp";
}
- 方法二：标签直接获取web下的静态资源
<a href="${pageContext.request.contextPath}/static/1.png">图片下载a>
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