SpringMVC

最新推荐文章于 2020-09-30 15:46:43 发布

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最新推荐文章于 2020-09-30 15:46:43 发布

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分类专栏： springMVC

本文链接：https://blog.youkuaiyun.com/qq_21907023/article/details/103213645

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文章目录

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。

1.springmvc的环境搭建及案例

1.1 pom依赖：
替换掉之前的spring-context

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

自定义标签

  <!-- ********************** 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-->
      
<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>

tomcat

	<!--tomcat-jsp-->
    <tomcat-jsp-api.version>8.0.47</tomcat-jsp-api.version>

	<!--tomcat与jsp的-->
    <dependency>
      <groupId>org.apache.tomcat</groupId>
      <artifactId>tomcat-jsp-api</artifactId>
      <version>${tomcat-jsp-api.version}</version>
    </dependency>

1.2 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.swx.ssm"/>

    <!--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="/js/" mapping="/js/**"/>-->


</beans>

1.3 修改web.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<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"
  metadata-complete="true">

    <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>

    <!-- 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-servlet.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>

1.4 测试hello word 案例
建立 controller层并在层下建立一个HelloController类

package com.swx.ssm.controller;

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

import javax.servlet.http.HttpServletRequest;

/**
 * @author Songwanxi
 * @site www.lentter.club
 * @company
 * @create  2019-11-22 11:42
 */
@Controller
public class HelloController {
    @RequestMapping("/hello")
    public String hello(HttpServletRequest req){
        req.setAttribute("msg","Hello word！！！");
        return "hello";
    }

    @RequestMapping("/helloMod")
    public ModelAndView helloMod(){
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("/hello");
        modelAndView.addObject("msg","modelAndView");
        return modelAndView;
    }
}

简单写一个jsp页面拿来进行测试：

<%--
  Created by IntelliJ IDEA.
  User: Lentter
  Date: 2019/11/22
  Time: 11:44
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
${msg}
</body>
</html>

启动tomcat，进行测试：
在这里插入图片描述

简单介绍SpringMVC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
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
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)

2. Springmvc实例crud

2.1 准备：
在这里插入图片描述
两个jsp页面：
BookList

<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<%@ page isELIgnored="false" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="/hyf"  prefix="h"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>书籍主页</title>
</head>
<body>
<h2>小说目录</h2>
	<br>
	<form action="${pageContext.request.contextPath}/book/list" method="post">
		<!--用户设置查询 一页20条记录  -->
	 <!-- 	<input type="hidden" name="rows" value="20"/> -->
		<!--用户设置不分页  -->
	 	<!-- <input type="hidden" name="pagination" value="false"/> -->
		书名：<input type="text" name="bname"> <input type="submit"
			value="确定">
	</form>
	<a href="${pageContext.request.contextPath}/book/preSave">增加</a>
	<table border="1" width="100%">
		<tr>
			<td>编号</td>
			<td>名称</td>
			<td>价格</td>
			<td>操作</td>
		</tr>
<
		 <c:forEach items="${bookList}" var="b">
			 <tr>
				<td>${b.bid }</td>
				<td>${b.bname }</td>
				<td>${b.price }</td>
				<td>
				  <a href="${pageContext.request.contextPath}/book/preSave?bid=${b.bid}">修改</a>
				  <a href="${pageContext.request.contextPath}/book/del/${b.bid}">删除</a>
				</td>
			</tr>
		</c:forEach>
	</table>
	<h:page pageBean="${pagebean}"></h:page>
</body>
</html>

bookEdit

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ page isELIgnored="false" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>编辑页面</title>
</head>
<body>
<form action="${pageContext.request.contextPath}${book.bname == null ?'/book/add' : '/book/edit'}" method="post">
 bid:  <input type="text" value="${b.bid}" name="bid"/><br>
 bname:<input type="text" value="${b.bname}" name="bname"/><br>
 price:<input type="text" value="${b.price}" name="price"/><br>
 <button type="submit">确认</button>
</form>
</body>
</html>

自定义标签：
h.tld

<?xml version="1.0" encoding="UTF-8" ?>
<taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
	version="2.0">
	<description>swx 1.1 core library</description>
	<display-name>swx core</display-name>
	<tlib-version>1.1</tlib-version>
	<short-name>c</short-name>
	<uri>/swx</uri>


	<tag>
		<name>page</name>
		<tag-class>com.swx.ssm.tag.PageTag</tag-class>
		<body-content>JSP</body-content>
		<attribute>
			<name>pageBean</name>
			<required>true</required>
			<rtexprvalue>true</rtexprvalue>
		</attribute>
	</tag>


</taglib>

Pagtag

package com.swx.ssm.tag;


import com.swx.ssm.util.PageBean;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.BodyTagSupport;
import java.io.IOException;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

public class PageTag extends BodyTagSupport {

    private static final long serialVersionUID = 383258790166308355L;

    private PageBean pageBean;

    public int doStartTag() throws JspException {
        JspWriter out = pageContext.getOut();
        try {
            out.print(toHTML());
        } catch (IOException e) {
            e.printStackTrace();
        }
        return SKIP_BODY;
    }

    private String toHTML() {
        StringBuilder sb = new StringBuilder();
//     拼接下一次分页请求搜提交的分页表单
        sb.append("<form id='pageBeanForm' action='"+pageBean.getUrl()+"' method='post'>");
        sb.append("<input type='hidden' name='page'> ");
        Map<String, String[]> paMap = pageBean.getPaMap();
        if(paMap != null && paMap.size()>0) {
            Set<Entry<String, String[]>> entrySet = paMap.entrySet();

            for (Entry<String, String[]> entry : entrySet) {
                for(String value :entry.getValue() ) {
                    if(!"page".equals(entry.getKey())) {
                        sb.append("<input type='hidden' name='"+entry.getKey()+"' value='"+value+"'>");
                    }
                }
            }
        }
        sb.append("</form>");
//     拼接分页条
        sb.append("<div style='text-align: right; font-size: 12px;'>");
        sb.append(" 每页"+pageBean.getRows()+"条，共"+pageBean.getTotal()+"条，第"+pageBean.getPage()+"页，共"+pageBean.getMaxPage()+"页&nbsp;&nbsp;");
        sb.append(" <a href='javascript:gotoPage(1)'>首页</a>&nbsp;&nbsp;");
        sb.append(" <a href='javascript:gotoPage("+pageBean.getPreviousPage()+")'>上一页</a>&nbsp;&nbsp;");
        sb.append(" <a href='javascript:gotoPage("+pageBean.getNextPage()+")'>下一页</a>&nbsp;&nbsp;");
        sb.append(" <a href='javascript:gotoPage("+pageBean.getMaxPage()+")'>尾页</a>&nbsp;&nbsp;");
        sb.append(" <input type='text' id='skipPage' style='text-align: center; font-size: 12px; width: 50px;'>&nbsp;&nbsp;");
        sb.append(" <a href='javascript:skipPage()'>Go</a>");
        sb.append(" </div>");
//     拼接分页的javascript 代码
        sb.append("<script type='text/javascript'>");
        sb.append("  function gotoPage(page) {");
        sb.append("     document.getElementById('pageBeanForm').page.value = page;");
        sb.append("     document.getElementById('pageBeanForm').submit();");
        sb.append(" }");
        sb.append(" function skipPage() { ");
        sb.append("   var page = document.getElementById('skipPage').value;");
        sb.append("   if(!page || isNaN(page) || parseInt(page)<1 || parseInt(page)>"+pageBean.getMaxPage()+"){");
        sb.append("       alert('请输入1~N的数字');");
        sb.append("        return;");
        sb.append("  }");
        sb.append("  gotoPage(page);");
        sb.append(" }");
        sb.append("</script> ");
        return sb.toString();
    }

    public PageBean getPageBean() {
        return pageBean;
    }

    public void setPageBean(PageBean pageBean) {
        this.pageBean = pageBean;
    }

}

后台控制文件BookController.java 并补全方法

package com.swx.ssm.controller;

import com.swx.ssm.model.Book;
import com.swx.ssm.service.BookService;
import com.swx.ssm.util.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;
import java.util.Map;

/**
 * @author Songwanxi
 * @site www.lentter.club
 * @company
 * @create  2019-11-23 15:02
 */
@Controller
@RequestMapping("/book")
public class BookController {
    @Autowired
    private BookService bookService;

    @RequestMapping("/list")
    public String list(Book book,HttpServletRequest req){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(req);
        List<Map> list = bookService.listPager(book, pageBean);
        req.setAttribute("bookList",list);
        req.setAttribute("pagebean",pageBean);
        return "bookList";
    }
    @RequestMapping("/add")
    public String add(Book book){
        bookService.insertSelective(book);
        return "redirect:/book/list";
    }
    @RequestMapping("/edit")
    public String edit(Book book){
        bookService.updateByPrimaryKeySelective(book);
        return "redirect:/book/list";
    }
    @RequestMapping("/del/{bid}")
    public String del(@PathVariable("bid") Integer bid){
        bookService.deleteByPrimaryKey(bid);
        return "redirect:/book/list";
    }
    @RequestMapping("/preSave")
    public String preSave(Book book,HttpServletRequest req){
        if (book == null || book.getBid() == null || book.getBid() == 0){
            return "bookEdit";
        }
        Map map = bookService.listPager(book, null).get(0);
        System.out.println(map);
        req.setAttribute("b",map);
        return "bookEdit";
    }


}

web.xml添加解决中文乱码：

<!--解决乱码  -->
    <filter>
        <filter-name>encodingFiter</filter-name>
        <filter-class>com.swx.ssm.util.EncodingFiter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>encodingFiter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

然后进行测试：
在这里插入图片描述
模糊查询：圣墟

另外：

这两种带参的方式都可以，只是在后台接受的方式不同。

3.五种返回值

package com.swx.ssm.controller;

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

import javax.servlet.http.HttpServletRequest;

/**
 * @author Songwanxi
 * @site www.lentter.club
 * @company
 * @create  2019-11-22 11:42
 *
 * 五种返回形式
 * 1，转发到web-inf
 * 2, 转发到根目录
 * 3, 转发到RequestMapping
 *
 * 4, 重定向到根目录
 * 5, 重定向RequestMapping
 *
 */
@Controller
public class HelloController {


    //1.转发到WEB-INF
    @RequestMapping("/req1")
    public String req1(){
        System.out.println("转发到WEB-INF下");
        return "a";
    }
    //2.转发到根目录下
    @RequestMapping("/req2")
    public String req2(){
        System.out.println("转发到根目录下");
        return "forward:/b.jsp";
    }
    //3.转发到RequestMapping
    @RequestMapping("/req3")
    public String req3(){
        System.out.println("转发到RequestMapping");
        return "forward:/req2";
    }

    //4.重定向到RequestMapping
        @RequestMapping("/red1")
        public String red1(){
            System.out.println("重定向到根目录");
            return "redirect:/b.jsp";
        }

    //5.重定向到RequestMapping
    @RequestMapping("/red2")
    public String red2(){
        System.out.println("重定向到RequestMapping");
        return "redirect:/req2";
    }


}

在这里插入图片描述

Springmvc静态资源处理

在springMVC中，默认将所有请求都当做RequestMapping处理，如果我们需要访问静态资源的话，需要将其过滤打开：

<!--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="/js/" mapping="/js/**"/>-->