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

 <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>${spring.version}</version>
      </dependency>

　　jstl依赖

<dependency>
          <groupId>jstl</groupId>
          <artifactId>jstl</artifactId>
          <version>1.2</version>
      </dependency>
      <dependency>
          <groupId>taglibs</groupId>
          <artifactId>standard</artifactId>
          <version>1.1.2</version>
      </dependency>

　　

  5.2 在WEB-INF下添加springmvc-servlet.xml(spring-mvc.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" xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
      http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    <!-- 通过context:component-scan元素扫描指定包下的控制器-->
    <!--1) 扫描com.javaxl.zf及子子孙孙包下的控制器(扫描范围过大，耗时)-->
    <aop:aspectj-autoproxy/>
    <context:component-scan base-package="com.lingerqi"/>

    <!--2) 此标签默认注册DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter -->
    <!--两个bean，这两个bean是spring MVC为@Controllers分发请求所必须的。并提供了数据绑定支持，-->
    <!--@NumberFormatannotation支持，@DateTimeFormat支持，@Valid支持，读写XML的支持（JAXB），读写JSON的支持（Jackson）-->
    <mvc:annotation-driven></mvc:annotation-driven>

    <!--3) ViewResolver -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!-- viewClass需要在pom中引入两个包：standard.jar and jstl.jar -->
        <property name="viewClass"
                  value="org.springframework.web.servlet.view.JstlView"></property>
        <property name="prefix" value="/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <!--4) 单独处理图片、样式、js等资源 -->
    <!--<mvc:resources location="/css/" mapping="/css/**"/>-->
    <!--<mvc:resources location="/images/" mapping="/images/**"/>-->
    <mvc:resources location="/static/" mapping="/static/**"/>


</beans>

　　5.3修改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_3_1.xsd"
         version="3.1">
  <display-name>Archetype Created Web Application</display-name>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
  </context-param>
  <!-- 读取Spring上下文的监听器 -->
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <!--中文乱码处理-->
<filter>
  <filter-name>encodingFilter</filter-name>
  <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
  <async-supported>true</async-supported>
  <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>
  <!-- Spring MVC servlet -->
  <servlet>
    <servlet-name>SpringMVC</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!--此参数可以不配置，默认值为：/WEB-INF/springmvc-servlet.xml-->
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>/WEB-INF/SpringMVC.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
    <!--web.xml 3.0的新特性，是否支持异步-->
    <async-supported>true</async-supported>
  </servlet>

  <servlet-mapping>
    <servlet-name>SpringMVC</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
</web-app>

　　

Springmvc之helloword实现

@Controller
public class MyController {
    @ResponseBody
    @RequestMapping("/hello1")
    public String hello1() {
        System.out.println("0030");
        return "0030";
    }

    @RequestMapping("/hello2")
    public String hello2() {
        System.out.println("零二七");
        return "hello";
    }

　　控制台以及网页截图：

 

Springmvc常用注解及返回值处理

返回值：

通过crud进行讲解

Controller

Requestmapping

Requestparam

传参

新建jsp页面如下

package com.lingerqi.controller;

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

import java.util.HashMap;
import java.util.Map;

/**
 * @author xyls
 * @blog name & blog address 027@0030
 * @create  2019-10-27 16:38
 */
@Controller
public class MyController {
  //转发到页面
    @RequestMapping("/forward1")
    public String forwadr1(){
        System.out.println("forward");
        return "forward1";
    }
    //转发到根路径下的页面
    @RequestMapping("/forward2")
    public String forwadr2(){
        return "forward:/forward2.jsp";
    }
    //转发到requestMapping下
    @RequestMapping("/forward3")
    public String forwadr3(){
        return "forward:/forward1";
    }
    //重定向到根路径下的页面
    @RequestMapping("/redirect1")
    public String redirece1(){
        return "redirect:/forward2.jsp";
    }
    //重定向到requestMapping下
    @RequestMapping("/redirect2")
    public String redirece2(){
        return "redirect:/forward1";
    }

}

　

常用注解：

package com.lingerqi.controller;

import com.lingerqi.model.Book;
import com.lingerqi.service.BookService;
import com.lingerqi.utils.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

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

/**
 * @author xyls
 * @blog name & blog address 027@0030
 * @create  2019-10-27 19:02
 */
@Controller
@RequestMapping("/book")
public class BookContorller {
    @Autowired
    private BookService bookService;

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

    @RequestMapping("/preSave")
    public String preSave(Book book,HttpServletRequest req) {
        if (book !=null &&  book.getBid()!=null && book.getBid()!=0 ){
            Book book1 = this.bookService.selectByPrimaryKey(book.getBid());
            req.setAttribute("book2",book1);
        }
        return "bookEdit";
    }

    @RequestMapping("/add")
    public String add(Book book,HttpServletRequest req) {
        this.bookService.insertSelective(book);
        return "redirect:/book/list";
    }

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

    @RequestMapping("/del/{bid}")
    public String del(@PathVariable("bid")Integer bid, HttpServletRequest req) {
        this.bookService.deleteByPrimaryKey(bid);
        return "redirect:/book/list";
    }


}

　　

 

 模糊查：

 

静态资源处理：

在springmvc-servlet.xml(spring-mvc.xml)中配置：

  <!--4) 单独处理图片、样式、js等资源 -->
    <!--<mvc:resources location="/css/" mapping="/css/**"/>-->
    <!--<mvc:resources location="/images/" mapping="/images/**"/>-->
    <mvc:resources location="/static/" mapping="/static/**"/>