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SSM框架---SpringMVC

2021-04-03 21:36:22   26  举报

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springMVC

SSM

作者其他创作

大纲/内容

回顾servlet

1、创建父项目

2、导入maven依赖

3、创建子模块

4、添加框架支持

5、子模块导入maven依赖

6、web.xml配置servlet

7、编写servlet测试类

1、继承HttpServlet类

2、重写doGet和doPost方法

1、获取前端参数

String method = req.getParameter("method");

2、调用业务层

3、视图转发

req.getRequestDispatcher("/WEB-INF/jsp/test.jsp").forward(req,resp);

8、在web.xml中注册servlet

<pre style="background-color: rgb(43, 43, 43); font-family: "JetBrains Mono", monospace; font-size: 9.8pt; color: rgb(169, 183, 198);"> <servlet> <servlet-name>hello</servlet-name> <servlet-class>com.learning.servlet.HelloServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>hello</servlet-name> <url-pattern>/hello</url-pattern> </servlet-mapping> </pre>

9、配置tomcat

配置一个SpringMVC

基础版

1、创建子模块，添加web支持

2、导入springmvc依赖

3、配置web.xml，注册DispatcherServlet

4、编写springmvc-servlet.xml

1、添加处理器映射器

BeanNameUrlHandlerMapping

2、添加处理器适配器

SimpleControllerHandlerAdapter

3、添加视图解析器

InternalResourceViewResolver

5、编写业务controller

6、把类交给SpringIOC容器，注册bean

7、编写需要跳转的页面

8、如果报错404，需要建立lib目录，添加jar包

9、如果报错500，去把lib中的老版本的jsp，servletjar包删除

注解版

1、创建子模块、添加web支持

2、在web.xml中注册springmvc

<pre style="background-color: rgb(43, 43, 43); font-family: "JetBrains Mono", monospace; font-size: 9.8pt; color: rgb(169, 183, 198);"><servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc-servlet.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </pre>

3、新建springmvc-servlet.xml文件

如果文件出错，打开setting、editor、file type、text、找到不对劲的名字，删除

4、创建controller

<pre style="background-color: rgb(43, 43, 43); font-family: "JetBrains Mono", monospace; font-size: 9.8pt; color: rgb(169, 183, 198);">/** * @author 22944 */ @Controller @RequestMapping("/hello") public class HelloAnnotationController { @RequestMapping("/h1") public String h1(Model model){ model.addAttribute("msg","你好啊"); return "hello"; } } </pre>

一个请求的执行过程

1、前端发送请求

2、servlet通过路径映射进入springmvc

<pre style="background-color: rgb(43, 43, 43); font-family: "JetBrains Mono", monospace; font-size: 9.8pt; color: rgb(169, 183, 198);"> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc-servlet.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </pre>

3、springmvc找到handleMapping

4、handleMapping找到对应的control返回给前端控制器，前端控制器再通过处理器适配器找到对应的controller

5、处理业务逻辑

6、返回一个ModelView给前端控制器

7、前端控制器转发给视图解析器，添加前缀后缀，找到对应的jsp页面，返回给前端控制器

8、前端控制器把返回的jsp返回给用户

SpringMVC的乱码过滤器

<pre style="background-color: rgb(43, 43, 43); font-family: "JetBrains Mono", monospace; font-size: 9.8pt; color: rgb(169, 183, 198);"><filter> <filter-name>encoding</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>encoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </pre>

json交互

1、新建子模块、添加web支持

2、maven导入jackson-databind依赖

3、注册DispatcherServlet

4、编写springmvc-servlet

5、注册过滤器

<pre style="background-color: rgb(43, 43, 43); font-family: "JetBrains Mono", monospace; font-size: 9.8pt; color: rgb(169, 183, 198);"> <filter> <filter-name>encoding</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>encoding</filter-name> <url-pattern>/</url-pattern> </filter-mapping> </pre>

6、编写Controller

7、乱码统一解决

SpringMVC拦截器

拦截器是aop思想的体现

1、编写web.xml

1、注册DispatcherServlet

<pre style="background-color: rgb(43, 43, 43); font-family: "JetBrains Mono", monospace; font-size: 9.8pt; color: rgb(169, 183, 198);"><pre style="font-family: "JetBrains Mono", monospace; font-size: 9.8pt;"> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:applicationContext.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping></pre></pre>

2、配置过滤器

<pre style="background-color: rgb(43, 43, 43); font-family: "JetBrains Mono", monospace; font-size: 9.8pt; color: rgb(169, 183, 198);"><pre style="font-family: "JetBrains Mono", monospace; font-size: 9.8pt;">  <filter> <filter-name>encoding</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>encoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </pre></pre>

2、编写applicationContext.xml

1、添加注解支持

2、自动扫描controller包

3、配置静态资源过滤

4、配置视图解析器

5、配置拦截器

3、编写controller类

1、新建config包

2、编写拦截器类

实现HandlerInterceptor接口，实现方法

文件示例

<pre style="background-color: rgb(43, 43, 43); font-family: "JetBrains Mono", monospace; font-size: 9.8pt; color: rgb(169, 183, 198);"><pre style="font-family: "JetBrains Mono", monospace; font-size: 9.8pt;">package com.learning.config; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * @author 小也 * @create 2021/4/2 22:11 */ public class MyInterceptor implements HandlerInterceptor { /** * return true 放行，执行下一个拦截器 * return false 拦截，不执行下一个拦截器 */ public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { System.out.println("=========方法执行前========="); return false; } public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { System.out.println("=========方法执行后========="); } public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { System.out.println("=========清理========="); } } </pre></pre>