Springmvc入门

Springmvc简介及配置

1. 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。

2. SpringMVC处理请求的流程

2.1 首先用户发送请求–>DispatherServlet

2.2 DispatcherServlet–>HandlerMapping

2.3 DispatcherServlet–>HandlerAdapter

2.4 HandlerAdapter–>处理器功能处理方法的调用

2.5 ModelAndView的逻辑视图名–>ViewRecolver

2.6 View–>渲染

2.7 返回控制权给DispatcherServlet，由DispatcherServlet返回呼应给用户，流程结束

3. SpringMVC核心开发步骤

3.1 DispatcherServlet在web.xml中的部署描述，从而拦截请求到springMVC

3.2 HandlerMapping的配置，从而将请求映射到处理器

3.3 HandlerAdapter的配置，从而支持多种类型的处理器

3.4 处理器(页面控制器)的配置，从而刊行功能处理

3.5 ViewResolver的配置，从而将逻辑视图名解析为具体的视图技术

4. SpringMVC的组件

4.1 前端控制器(DispatcherServlet)

4.2 请求到处理器映射(HandlerMapping)

4.3 处理器适配器(HandlerAdapter)

4.4 视图解析器(ViewResolver)

4.5 处理器或页面控制器(Controller)

4.6 验证器(Validator)

4.6 命令对象(Command 请求参数绑定到的对象就叫命令对象)

4.7 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)

5. 如何在项目中添加springmvc

5.1 添加相关依赖

        org.springframework
        spring-webmvc
        ${spring.version}
      

== 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

          jstl
          jstl
          1.2
      
      
          taglibs
          standard
          1.1.2
      

5.2 在WEB-INF下添加springmvc-servlet.xml(spring-mvc.xml)

5.3 修改web.xml

  Archetype Created Web Application
  
    contextConfigLocation
    classpath:applicationContext.xml
  
  
  
    org.springframework.web.context.ContextLoaderListener
  

  
  
    SpringMVC
    org.springframework.web.servlet.DispatcherServlet
    
    
      contextConfigLocation
      /WEB-INF/spring-mvc.xml
    
    1
    
    true
  
  
    SpringMVC
    /
  

Springmvc之helloword实现

第一个springMVC程序：HelloWorld

package com.yzp.controller;

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

/**
 * @author易泽鹏
 * @site 16670388677
 * @company
 * @create  2022-08-23 19:48
 */
@Controller
public class HelloController {
    @RequestMapping("/hello")
    public String hello(){
        return "index";
    }
}

Springmvc常用注解及返回值处理

三种常用注解
@Controller
@Requestmapping
@Requestparam

crud

package com.yzp.controller;

import com.yzp.biz.Bookbiz;
import com.yzp.model.Book;
import com.yzp.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author易泽鹏
 * @site 16670388677
 * @company
 * @create  2022-08-23 20:20
 */
 @Controller
@RequestMapping("/book")
public class BookController {
    @Autowired
    private Bookbiz bookbiz;
    @RequestMapping("/preSave")
    public String preSave(Book book,HttpServletRequest request){
        if(book.getId() != null){
            Book b = this.bookbiz.selectByPrimaryKey(book.getId());
            request.setAttribute("book2",b);
        }

        return "bookEdit";
    }

    @RequestMapping("/add")
    public String add(Book book){
        this.bookbiz.insert(book);
        return "redirect:/book/list";
    }

    @RequestMapping("/del/{id}")
    public String del(@PathVariable(value = "id") long id){
        this.bookbiz.deleteByPrimaryKey(id);
        return "redirect:/book/list";
    }

    @RequestMapping("/list")
    public String list(HttpServletRequest request, Book book){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        List list = this.bookbiz.listPager(book, pageBean);
        request.setAttribute("bookList",list);
        request.setAttribute("pageBean",pageBean);
        return "bookList";
    }

    @RequestMapping("/edit")
    public String edit(Book book){
        this.bookbiz.updateByPrimaryKeySelective(book);
        return "redirect:/book/list";
    }
}

}