首页 博客列表 精选博客 智能问答 chat-GPT 关于我
Java学习路线-64：SpringMVC
发布日期：2021-07-01 06:11:41 浏览次数：2 分类：技术文章

本文共 24340 字，大约阅读时间需要 81 分钟。

1、MVC 框架作用：

  1. 将 url 映射到 java 类或 java 类的方法
  2. 封装用户提交的数据
  3. 处理请求-调用相关的业务处理-封装响应数据
  4. 将响应的数据进行渲染 jsp,html,freemaker 等

2、Spring MVC 是一个轻量级的基于响应的 MVC 框架

3、Spring MVC 优势

  1. 性能比 Struts2 好
  2. 简单，便捷，易学
  3. 和 Spring 无缝集成（使用 spring ioc, aop）
  4. 使用约定优先于配置
  5. 能够进行简单 junit 测试
  6. 支持 Restful 风格
  7. 异常处理
  8. 本地化，国际化
  9. 数据验证，类型转换
  10. 拦截器
  11. 使用的公司多

4、结构

在这里插入图片描述

spring-beans

spring-context
spring-core
spring-web
spring-webmvc
commons-logging

项目目录

.├── pom.xml└── src    ├── main    │   ├── java    │   │   └── com    │   │       └── pengshiyu    │   │           └── controller    │   │               └── HelloController.java    │   ├── resources    │   │   └── springmvc-servlet.xml    │   └── webapp    │       ├── WEB-INF    │       │   ├── jsp    │       │   │   └── hello.jsp    │       │   └── web.xml    │       └── index.html    └── test        └── java

配置文件

pom.xml

   
       
    
     4.0.0
        
    
     org.example
        
    
     spring-mvc-demo
        
    
     1.0-SNAPSHOT
        
            
                 
                  
                      
       
        org.apache.tomcat.maven
                       
       
        tomcat7-maven-plugin
                       
       
        2.2
                       
                           
        
         8080
                            
        
         /
                            
        
         UTF-8
                            
                            
        
         true
                            
        
         src/main/webapp/WEB-INF/web.xml
                            
        
         true
                        
                   
              
         
        
            
             
                 
      
       org.springframework
                  
      
       spring-core
                  
      
       5.2.6.RELEASE
              
             
             
                 
      
       org.springframework
                  
      
       spring-beans
                  
      
       5.2.6.RELEASE
              
             
             
                 
      
       org.springframework
                  
      
       spring-context
                  
      
       5.2.6.RELEASE
              
             
             
                 
      
       org.springframework
                  
      
       spring-web
                  
      
       5.2.6.RELEASE
              
             
             
                 
      
       org.springframework
                  
      
       spring-webmvc
                  
      
       5.2.6.RELEASE
              
             
             
                 
      
       org.springframework
                  
      
       spring-aop
                  
      
       5.2.6.RELEASE
              
             
             
                 
      
       org.springframework
                  
      
       spring-expression
                  
      
       5.2.6.RELEASE
              
             
             
                 
      
       commons-logging
                  
      
       commons-logging
                  
      
       1.2
              
             
                 
      
       javax.servlet
                  
      
       javax.servlet-api
                  
      
       4.0.1
                  
      
       provided
              
             
                 
      
       jstl
                  
      
       jstl
                  
      
       1.2

src/main/webapp/WEB-INF/web.xml

   
       
        
            
     
      springmvc
             
     
      org.springframework.web.servlet.DispatcherServlet
             
             
                 
      
       contextConfigLocation
                  
      
       classpath:springmvc-servlet.xml
              
             
             
     
      1
         
        
            
     
      springmvc
             
             
     
      /

src/main/resources/springmvc-servlet.xml

控制器

src/main/java/com/pengshiyu/controller/HelloController.java

package com.pengshiyu.controller;import org.springframework.web.servlet.ModelAndView;import org.springframework.web.servlet.mvc.Controller;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class HelloController implements Controller {
       public ModelAndView handleRequest(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception {
           // 封装要显示的数据        ModelAndView modelAndView = new ModelAndView();        modelAndView.addObject("name", "Tom");        modelAndView.addObject("age", 25);        // 视图名        modelAndView.setViewName("hello");        return modelAndView;    }}

视图文件

src/main/webapp/WEB-INF/jsp/hello.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%>${name}${age}

访问测试

GET http://localhost:8080/helloTom 25

Spring-MVC 注解开发

修改配置文件

src/main/resources/springmvc-servlet.xml

修改 Controller

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@Controllerpublic class HelloController  {
       @RequestMapping("/hello")    public ModelAndView handleRequest(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception {
           // 封装要显示的数据        ModelAndView modelAndView = new ModelAndView();        modelAndView.addObject("name", "Tom");        modelAndView.addObject("age", 24);        // 视图名        modelAndView.setViewName("hello");        return modelAndView;    }}

配置总结

1、通过 url 对应 bean

适用于小型的应用系统

2、为 url 分配 bean

       
            
                 
                  
      
       helloController

3、注解

Controller 配置对应的注解

结果跳转方式

1、返回 ModelAndView 对象

根据 view 的名称和视图解析器，会跳转到指定的页面

页面：视图解析器的前缀+ view name + 视图解析器的后缀

springmvc-servlet.xml

   
       
        
            
             
             
             
             
         
        
    
   
package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@Controllerpublic class HelloController {
       @RequestMapping("/hello")    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response)            throws Exception {
           // 封装要显示的数据        ModelAndView modelAndView = new ModelAndView();        modelAndView.addObject("name", "Tom");        // 相当于：        // request.setAttribute("name", "Tom");        modelAndView.setViewName("hello");        // WEB-INF/jsp/hello.jsp        // 类似转发        return modelAndView;    }}

2、返回字符串

不需要视图解析器

springmvc-servlet.xml

   
       
    
   
package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@Controllerpublic class HelloController {
       @RequestMapping("/hello")    public void handleRequest(HttpServletRequest request, HttpServletResponse response)            throws Exception {
           response.getWriter().println("hello");    }}

3、重定向(地址改变)

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@Controllerpublic class HelloController {
       @RequestMapping("/hello")    public void handleRequest(HttpServletRequest request, HttpServletResponse response)            throws Exception {
           response.sendRedirect("index.jsp");    }}

或者

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@Controllerpublic class HelloController {
       @RequestMapping("/hello")    public String handleRequest(HttpServletRequest request, HttpServletResponse response)            throws Exception {
           // 不需要视图解析        return "redirect:index.jsp";    }}

4、转发（地址不变）

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@Controllerpublic class HelloController {
       @RequestMapping("/hello")    public void handleRequest(HttpServletRequest request, HttpServletResponse response)            throws Exception {
           request.setAttribute("name", "Tom");        request.getRequestDispatcher("index.jsp").forward(request, response);    }}

或者

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@Controllerpublic class HelloController {
       @RequestMapping("/hello")    public String handleRequest(HttpServletRequest request, HttpServletResponse response)            throws Exception {
           return "hello";    }}

或者

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@Controllerpublic class HelloController {
       @RequestMapping("/hello")    public String handleRequest(HttpServletRequest request, HttpServletResponse response)            throws Exception {
           return "forward:index.jsp";    }}

数据处理

1、提交数据

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;@Controllerpublic class HelloController {
       @RequestMapping("/hello")    public String handleRequest(String name){
           System.out.println(name);        return "index.jsp";    }}
GET http://localhost:8080/hellonullGET http://localhost:8080/hello?name=TomTom

2、指定参数名

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;@Controllerpublic class HelloController {
       @RequestMapping("/hello")    public String handleRequest(@RequestParam("uname") String name){
           System.out.println(name);        return "index.jsp";    }}
GET http://localhost:8080/hello?uname=TomTom

3、提交对象

实体类

package com.pengshiyu.bean;public class User {
       private String name;    private int age;    public String getName() {
           return name;    }    public void setName(String name) {
           this.name = name;    }    public int getAge() {
           return age;    }    public void setAge(int age) {
           this.age = age;    }    @Override    public String toString() {
           return "User{" +                "name='" + name + '\'' +                ", age=" + age +                '}';    }}
package com.pengshiyu.controller;import com.pengshiyu.bean.User;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;@Controllerpublic class HelloController {
       @RequestMapping("/user")    public String user(User user){
           System.out.println(user);        return "index.jsp";    }}
GET http://localhost:8080/user?name=Tom&age=23User{name='Tom', age=23}

将数据显示到 UI 层

1、通过 ModelAndView 需要视图解析器

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@Controllerpublic class HelloController {
       @RequestMapping("/hello")    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response)            throws Exception {
           // 封装要显示的数据        ModelAndView modelAndView = new ModelAndView();        modelAndView.addObject("name", "Tom");        // 相当于：        // request.setAttribute("name", "Tom");        modelAndView.setViewName("hello");        // WEB-INF/jsp/hello.jsp        // 类似转发        return modelAndView;    }}

2、通过 ModelMap 不需要视图解析器

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.ui.ModelMap;import org.springframework.web.bind.annotation.RequestMapping;@Controllerpublic class HelloController {
       @RequestMapping("/user")    public String user(String name, ModelMap modelMap){
           System.out.println(name);        modelMap.addAttribute("name", name);        return "index.jsp";    }}

区别：ModelAndView ModelMap

相同点：

  1. 都可以将数据封装显示到表示层页面

不同点：

  1. ModelAndView 可以指定跳转的视图，而 ModelMap 不能
  2. ModelAndView 需要视图解析器，而 ModelMap 不需要配置

乱码和 Restful

通过过滤器解决

web.xml

   
       
    
     CharacterEncodingFilter
        
    
     org.springframework.web.filter.CharacterEncodingFilter
        
            
     
      encoding
             
     
      utf-8
         
    
   
       
    
     CharacterEncodingFilter
        
    
     /*

2、Restful

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.ui.ModelMap;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestMapping;@Controllerpublic class HelloController {
       @RequestMapping("/user/{id}")    public String user(@PathVariable int id, ModelMap modelMap){
           System.out.println(id);        modelMap.addAttribute("name", id);        return "/index.jsp";    }}
GET http://localhost:8080/user/123123

3、通过参数访问处理方法

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.ui.ModelMap;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;@Controller@RequestMapping("/user")public class HelloController {
        // /user?method=add    @RequestMapping(params = {
   "method=add"}, method = RequestMethod.GET)    public String add(ModelMap modelMap){
           modelMap.addAttribute("name", "add");        return "/index.jsp";    }    // /user?method=delete    @RequestMapping(params = {
   "method=delete"}, method = RequestMethod.GET)    public String delete(ModelMap modelMap){
           modelMap.addAttribute("name", "delete");        return "/index.jsp";    }}

文件上传

依赖

commons-io
commons-fileupload

pom.xml

   
       
    
     commons-io
        
    
     commons-io
        
    
     2.7
    
   
   
       
    
     commons-fileupload
        
    
     commons-fileupload
        
    
     1.4

配置文件

src/main/resources/springmvc-servlet.xml

src/main/java/com/pengshiyu/controller/HelloController.java

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.multipart.commons.CommonsMultipartFile;import javax.servlet.http.HttpServletRequest;import java.io.*;@Controllerpublic class HelloController {
       @RequestMapping(value = "/upload", method = RequestMethod.GET)    public String upload(){
           return "/template/upload.jsp";    }    @RequestMapping(value = "/upload", method = RequestMethod.POST)    public String upload(@RequestParam("file")  CommonsMultipartFile file, HttpServletRequest request) throws IOException {
           String path = request.getRealPath("/uploads");        InputStream is = file.getInputStream();        System.out.println(file.getOriginalFilename());        OutputStream os = new FileOutputStream(new File(path, file.getOriginalFilename()));        int len = 0;        byte[] buffer = new byte[400];        while ((len = is.read(buffer)) != -1){
               os.write(buffer, 0, len);        }        is.close();;        os.close();        return "/index.jsp";    }}

src/main/webapp/template/upload.jsp

Ajax 和 JSON

1、Ajax

为了直接获取 html 文件，将配置文件匹配规则修改如下

       
    
     springmvc
        
        
    
     *.do
    
   
package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import javax.servlet.http.HttpServletResponse;import java.io.IOException;@Controllerpublic class HelloController {
       @RequestMapping(value = "/ajax")    public void ajax(String name, HttpServletResponse response) throws IOException {
           System.out.println(name);        response.getWriter().println("ok");    }}

2、JSON

jackson-annotations
jackson-core
jackson-databind

   
       
    
     com.fasterxml.jackson.core
        
    
     jackson-annotations
        
    
     2.11.0
    
   
   
       
    
     com.fasterxml.jackson.core
        
    
     jackson-databind
        
    
     2.11.0
    
   
   
       
    
     com.fasterxml.jackson.core
        
    
     jackson-core
        
    
     2.11.0

配置 JSON 转换器

   
       
        
            
                 
                      
       
        text/plain;charset=UTF-8
                   
              
         
        
        
        
            
                 
                      
                       
                   
              
         
        
    
   
package com.pengshiyu.controller;import com.pengshiyu.bean.User;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.ResponseBody;import java.io.IOException;import java.util.ArrayList;import java.util.List;@Controllerpublic class HelloController {
       @RequestMapping("/json")    @ResponseBody    public List
   
     ajax() throws IOException {
           List
    
      users = new ArrayList
     
      ();        users.add(new User("Tom", 23));        users.add(new User("Jack", 24));        return users;    }}

拦截器

interceptor

1、实现 HandlerInterceptor 接口
DispatcherServlet

package com.pengshiyu.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 {
       // 在请求处理的方法执行之前执行，    // 返回true执行下一个拦截器，    // 返回false不执行下一个拦截器    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
           System.out.println("preHandle");        return true;    }    // 在处理方法执行之后执行    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
           System.out.println("postHandle");    }    // 在DispatcherServlet 之后执行 清理工作    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
           System.out.println("afterCompletion");    }}

2、配置拦截器

3、执行顺序

package com.pengshiyu.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import javax.servlet.http.HttpServletResponse;import java.io.IOException;@Controllerpublic class HelloController {
       @RequestMapping("/echo")    public void echo(HttpServletResponse response) throws IOException {
           System.out.println("echo");        response.getWriter().println("echo");    }}
preHandleechopostHandleafterCompletion

登录拦截器实现

配置

   
       
            
             
             
                 
                      
                           
        
         login.do

拦截器

package com.pengshiyu.interceptor;import org.springframework.web.servlet.HandlerInterceptor;import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.util.List;public class MyInterceptor implements HandlerInterceptor {
       private List
   
     allowedUrls;    // 在请求处理的方法执行之前执行，    // 返回true执行下一个拦截器，    // 返回false不执行下一个拦截器    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
           System.out.println("preHandle");        // 解决中文打印乱码输出        response.setContentType("text/html;charset=utf-8");        // 判断session        Object user = request.getSession().getAttribute("user");        if(user != null){
               return true;        }        // 判断放行路径        String url = request.getRequestURL().toString();        System.out.println(url);        for(String temp: allowedUrls){
               if(url.endsWith(temp)){
                   return true;            }        }        // 如果没有登录就重定向到登录页面        response.sendRedirect("/login.do");        return false;    }    // 在处理方法执行之后执行    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
           System.out.println("postHandle");    }    // 在DispatcherServlet 之后执行 清理工作    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
           System.out.println("afterCompletion");    }    public List
    
      getAllowedUrls() {
           return allowedUrls;    }    public void setAllowedUrls(List
     
       allowedUrls) {
           this.allowedUrls = allowedUrls;    }}

User 类

package com.pengshiyu.bean;public class User {
       private String name;    private String password;    public User() {
       }    public User(String name, String password) {
           this.name = name;        this.password = password;    }    public String getPassword() {
           return password;    }    public void setPassword(String password) {
           this.password = password;    }    public String getName() {
           return name;    }    public void setName(String name) {
           this.name = name;    }    @Override    public String toString() {
           return "User{" +                "name='" + name + '\'' +                ", password='" + password + '\'' +                '}';    }}

Controller

package com.pengshiyu.controller;import com.pengshiyu.bean.User;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import java.io.IOException;@Controllerpublic class UserController {
       @RequestMapping("/userInfo")    public void userInfo(HttpSession session, HttpServletResponse response) throws IOException {
           User user = (User) session.getAttribute("user");        response.getWriter().println(user);    }    @RequestMapping(value = "/login", method = RequestMethod.GET)    public String login() throws IOException {
           return "/template/login.jsp";    }    @RequestMapping(value = "/login", method = RequestMethod.POST)    public void login(User user, HttpSession session, HttpServletResponse response) throws IOException {
           String message = "";        if ("root".equals(user.getName()) && "123".equals(user.getPassword())) {
               message = "登录成功";            session.setAttribute("user", user);        } else {
               message = "用户名或密码错误";        }        response.getWriter().println(message);    }}

登录页

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%>
登录

转载地址：https://pengshiyu.blog.csdn.net/article/details/106909854 如侵犯您的版权，请留言回复原文章的地址，我们会给您删除此文章，给您带来不便请您谅解！

上一篇：Java学习路线-65：整合 SSM-Spring+SpringMVC+MyBatis
下一篇：Java学习路线-63：maven整合ssm-spring+struts+mybatis

发表评论

最新留言

逛到本站，mark一下
[***.202.152.39]2024年04月16日 19时14分10秒

关于作者

    喝酒易醉，品茶养心，人生如梦，品茶悟道，何以解忧？唯有杜康！
-- 愿君每日到此一游！

推荐文章

linux中的sh脚本语法【转】 2019-05-02
区别数据结构中的堆栈与内存中的堆栈的个人总结【转】 2019-05-02
c++中冒号（:）和双冒号（::）的用法【转】 2019-05-02
谭浩强《C++面向对象程序设计》知识点总结 2019-05-02
Android深入浅出之Binder机制 2019-05-02
linux查看硬件信息 2019-05-02
linux支持大于4G内存 2019-05-02
WM_GETINFO相关 2019-05-02
[收藏] FC交换机基础知识详解 2019-05-02
Linux调试工具 2019-05-02
用Eclipse和GDB构建ARM交叉编译和在线调试环境 2019-05-02
GDB命令大全 2019-05-02
IT行业培训必读：优秀程序员的十个习惯 2019-05-02
StringIO和BytesIO 2019-05-02
财务分析与决策：同型分析 2019-05-02
Android studio出现：Your project path contains non-ASCII characters. 2019-05-02
Android--Error:Library projects cannot enable Jack. Jack is enabled in default config 2019-05-02
【语言-c#】C# 超级整数计算 2019-05-02
【软件-Doxgen】工具：程序代码生成xml文档（doxgen） 2019-05-02
【框架-MFC】CMFCPropertyGridCtrl（chenlu1）：属性值改变事件的触发与处理 2019-05-02
白红宇的个人博客 - 记录点点滴滴的事 - 您是第 312075999 位访客
访问时间: 2024-05-08 19:42:58 访问IP: 3.138.174.195     Copyright © 2020 - 2023 blog.css8.cn 京ICP备2021015314号-1 手机版