SPRINGMYBATIS01 Unit04：实战技巧 、 登录

1. 基于注解的SpringMVC应用

(1)编程步骤

step1.导包。spring-webmvcstep2.添加spring配置文件。step3.配置DispatcherServlet。step4.写Controller

step5.写jspstep6.在配置文件当中，添加ViewResolver配置，    添加组件扫描，添加MVC注解扫描。   

(2).读取请求参数值

1）方式一 通过request提供的方法

2) 方式二 通过@RequestParam注解

3) 方式三 通过javabean

step1. 先写一个java类

step2. 将该类作为方法参数

(3)向页面传值

1)方式一 将数据绑订到request

2)方式二 返回ModelAndView

3)方式三 将数据添加到ModelMap

4)方式四 将数据绑订到session

(4)重定向

1)方法的返回值是String

比如  return "redirect:toIndex.do";

2)方法的返回值是ModelAndView

比如    RedirectView rv = new RedirectView("toIndex.do");    ModelAndView mav = new ModelAndView(rv);

---

代码演示：

/springmvc-day02/pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">  <modelVersion>4.0.0</modelVersion>  <groupId>welkin</groupId>  <artifactId>springmvc-day02</artifactId>  <version>0.0.1-SNAPSHOT</version>  <packaging>war</packaging>    <dependencies>    <dependency>        <groupId>org.springframework</groupId>        <artifactId>spring-webmvc</artifactId>        <version>3.2.8.RELEASE</version>    </dependency>  </dependencies></project>

/springmvc-day02/src/main/java/controller

adminParam.java

package controller;/* * 用于封装请求参数值 *      属性名与请求参数名一致 *      注： *              名称要一样，类型要匹配（会做类型转换，比如将字符串转换成int） *      提供相应的get/set方法 */public class adminParam {    private String adminCode;    private String pwd;    public String getAdminCode() {        return adminCode;    }    public void setAdminCode(String adminCode) {        this.adminCode = adminCode;    }    public String getPwd() {        return pwd;    }    public void setPwd(String pwd) {        this.pwd = pwd;    }}

HelloController.java

package controller;import java.util.HashMap;import java.util.Map;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpSession;import org.springframework.stereotype.Controller;import org.springframework.ui.ModelMap;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.servlet.ModelAndView;import org.springframework.web.servlet.view.RedirectView;/** * 处理器类  * 1.不用实现Controller  * 2.方法名不做要求，返回值可以是ModelAndView，也可以是String  * 3.可以添加多个方法 * 4.使用@Controller  * 5.可以在方法前或者类前添加@RequestMapping * http://ip:port/springmvc-day02/hello.do */@Controllerpublic class HelloController {    @RequestMapping("/hello.do")    public String hello() {        System.out.println("hello()");        // 返回视图名        return "hello";    }    @RequestMapping("/toLogin.do")    public String toLogin() {        System.out.println("toLogin()");        return "login";    }    @RequestMapping("/login.do")    /*     * DispatcherServlet在调用处理器的方法之前，会利用Java反射机制分析方法的结构，比如这儿，通过分析会将请求对象传过来（了解）。     */    public String login(HttpServletRequest request) {        System.out.println("login()");        String adminCode = request.getParameter("adminCode");        System.out.println("adminCode:" + adminCode);        return "index";    }    @RequestMapping("/login2.do")    /*     * DistpatcherServlet调用处理器的方法之前，会分析方法的结构。这儿，会调用request对象的方法，先获得参数值，然后赋给对应的形参。（了解）     * 如果不一致，要@RequestParam注解     */    public String login2(String adminCode,@RequestParam("pwd") String pwd){        System.out.println("login2()");        System.out.println("adminCode:"+adminCode+"\n"+"pwd:"+pwd);        return "index";         }    @RequestMapping("/login3.do")    /*     * DistpatcherServlet会将AdminParam对象创建好（会将请求参数值赋给相应的属性）。     */    public String login3(adminParam ap){        System.out.println("login3()");        String adminCode = ap.getAdminCode();        String pwd = ap.getPwd();        System.out.println("adminCode:"+adminCode+"\n"+"pwd:"+pwd);        return "index";    }    @RequestMapping("/login4.do")    public String login4(adminParam ap,HttpServletRequest request){        System.out.println("login4()");        String adminCode = ap.getAdminCode();        request.setAttribute("adminCode", adminCode);        //默认情况下，DistpatcherServlet会使用转发。        return "index";         }    @RequestMapping("/login5.do")    public ModelAndView login5(adminParam ap){        System.out.println("login5()");        String adminCode = ap.getAdminCode();        //step1.将数据添加到Map对象里面        Map<String,Object> data = new HashMap<String, Object>();        //相当于执行了request.setAttribute        data.put("adminCode", adminCode);        //step2.将Map对象添加到ModelAndView        ModelAndView mav = new ModelAndView("index",data);        return mav;    }    @RequestMapping("/login6.do")    public String login6(adminParam ap,ModelMap mm){        System.out.println("login6()");        String adminCode = ap.getAdminCode();        //相当于执行了request.setAttribute        mm.addAttribute("adminCode",adminCode);        return "index";    }    @RequestMapping("/login7.do")    public String login7(adminParam ap,HttpSession session){        System.out.println("login7()");        String adminCode = ap.getAdminCode();        session.setAttribute("adminCode", adminCode);        return "index";    }    @RequestMapping("/login8")    public String login8(){        System.out.println("login8()");        return "redirect:toIndex.do";    }    @RequestMapping("/toIndex")    public String toIndex(){        System.out.println("toIndex()");        return "index";    }    @RequestMapping("/login9.do")    public ModelAndView login9(){        System.out.println("login9()");        RedirectView rv = new RedirectView("toIndex.do");        ModelAndView mav = new ModelAndView(rv);        return mav;    }    @RequestMapping("/toBmi.do")    public String toBmi() {        System.out.println("toBmi()");        return "bmi";    }    @RequestMapping("/bmi.do")    public String bmi(HttpServletRequest request) {        System.out.println("bmi()");        String height = request.getParameter("height");        String weight = request.getParameter("weight");        double bmi = Double.parseDouble(weight) / Double.parseDouble(height) / Double.parseDouble(height);        String status = "正常";        if (bmi < 19) {            status = "过轻";        }        if (bmi > 25) {            status = "过重";        }        request.setAttribute("status", status);        request.setAttribute("bmi", bmi);        return "view";        }}

/springmvc-day02/src/main/resources/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:jdbc="http://www.springframework.org/schema/jdbc"      xmlns:jee="http://www.springframework.org/schema/jee"     xmlns:tx="http://www.springframework.org/schema/tx"    xmlns:aop="http://www.springframework.org/schema/aop"     xmlns:mvc="http://www.springframework.org/schema/mvc"    xmlns:util="http://www.springframework.org/schema/util"    xmlns:jpa="http://www.springframework.org/schema/data/jpa"    xsi:schemaLocation="        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd        http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd        http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd        http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd">    <!-- 配置组件扫描 -->    <context:component-scan base-package="controller"></context:component-scan>    <!-- 配置MVC注解扫描 -->    <mvc:annotation-driven />    <!-- 配置视图解析器 -->        <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">        <property name="prefix" value="/WEB-INF/" />        <property name="suffix" value=".jsp" />    </bean></beans>

/springmvc-day02/src/main/webapp/WEB-INF

bmi.jsp

<%@ page contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><html><head></head><body style="font-size: 30px;">    <form action="bmi.do" method="post">        身高(米):<input name="height" /><br />        体重(公斤):<input name="weight" /><br />        <br /> <input type="submit" value="确定" />    </form></body></html>

hello.jsp

<h1>hello,SpringMVC!</h1>

index.jsp

<h1>index</h1>adminCode:${adminCode }

login.jsp

<%@page pageEncoding="UTF-8" contentType="text/html;charset=UTF-8"%><html>    <head></head>    <body style="font-size:30px;">        <form action="login9.do" method="post">            账号：<input name="adminCode"/><br/>            密码：<input type="password" name="pwd"/><br/>            <input type="submit" value="登录"/>        </form>    </body></html>

view.jsp

<%@ page contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><html><head></head><body style="font-size: 30px;">BMI指数:${bmi } 状态:${status}</body></html>

web.xml

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5"> <servlet>    <servlet-name>springmvc</servlet-name>    <servlet-class>             org.springframework.web.servlet.DispatcherServlet    </servlet-class>    <!--         DispatcherServlet的初始化方法会启动        spring容器，contextConfigLocation用        来指定spring配置文件的位置。     -->    <init-param>        <param-name>contextConfigLocation</param-name>        <param-value>classpath:spring-mvc.xml</param-value>    </init-param>    <load-on-startup>1</load-on-startup></servlet><servlet-mapping>    <servlet-name>springmvc</servlet-name>    <url-pattern>*.do</url-pattern></servlet-mapping></web-app>