SpringMVC（七）参数的自动装配和路径变量

1.参数自动装配（四种）

首先准备一个用户信息类和车类

package demo08ParamAuto01.AutoWire;

import java.util.List;

/**
 * Created by mycom on 2018/3/26.
 */
public class UserInfo {
    private String username;
    private String password;
    private Car car;
    private List<Car> list;

    public List<Car> getList() {
        return list;
    }

    public void setList(List<Car> list) {
        this.list = list;
    }

    public Car getCar() {
        return car;
    }

    public void setCar(Car car) {
        this.car = car;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

package demo08ParamAuto01.AutoWire;

/**
 * Created by mycom on 2018/3/26.
 */
public class Car {
    private String brand;

    public String getBrand() {
        return brand;
    }

    public void setBrand(String brand) {
        this.brand = brand;
    }
}

在控制器类中

package demo08ParamAuto01.AutoWire;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * Created by mycom on 2018/3/26.
 */
@Controller
public class UserInfoController {
    //零散参数自动装配
    @RequestMapping("/login")
    public String doLogin(String username, String password, Model model){
        model.addAttribute("username",username);
        System.out.println(username);
        System.out.println(password);
        return "success";
    }

    //对象参数自动装配
    @RequestMapping("/loginUserInfo")
    public String doLoginUserInfo(UserInfo info, Model model){
        model.addAttribute("username",info.getUsername());
        System.out.println(info.getUsername());
        System.out.println(info.getPassword());
        return "success";
    }


    //域属性自动装配
    @RequestMapping("/loginUserInfoCar")
    public String doLoginUserInfoCar(UserInfo info, Model model){
        model.addAttribute("username",info.getUsername());
        System.out.println(info.getUsername());
        System.out.println(info.getPassword());
        System.out.println(info.getCar().getBrand());
        return "success";
    }

    //集合自动装配
    @RequestMapping("/loginUserInfoList")
    public String doLoginUserInfoList(UserInfo info, Model model){
        model.addAttribute("username",info.getUsername());
        System.out.println(info.getUsername());
        System.out.println(info.getPassword());
        System.out.println(info.getCar().getBrand());
        System.out.println(info.getList().get(0).getBrand());
        System.out.println(info.getList().get(1).getBrand());
        return "success";
    }
}

在配置文件中，要配置一个包扫描器

<?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:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <context:component-scan base-package="demo08ParamAuto01.AutoWire"></context:component-scan>

    <!--视图解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>


</beans>

在页面上

<%--
  Created by IntelliJ IDEA.
  User: mycom
  Date: 2018/3/26
  Time: 11:57
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/loginUserInfoList" method="post">
    用户名：<input name="username"/>
    密码：<input name="password"/>
    爱车：<input name="car.brand">
    车1：<input name="list[0].brand">
    车2：<input name="list[1].brand">
    名：<input name="uname">
    <input type="submit" value="提交">

</form>
</body>
</html>

2.路径变量  @PathVariable

路径参数类似请求参数，但没有key部分，只是一个值。例如下面的URL: 
　http://localhost:9090/showUser/spring 
其中的spring是表示用户的密码字符串。在Spring MVC中，spring被作为路径变量用来发送一个值到服务器。Sping 3以后Spring 3以后支持注解@PathVariable用来接收路径参数。为了使用路径变量，首先需要在RequestMapping注解的值属性中添加一个变量，该变量必须放在花括号之间

//路径变量
    @RequestMapping("/loginUserInfoPath/{username}")
    public String doLoginUserInfoPath(@PathVariable("username") String uname,String username){
        System.out.println(uname);
        System.out.println(username);
        return "success";
    }

不要忘记修改web.xml和springmvc.xml的配置文件的路径和包的路径

在页面上

<%--
  Created by IntelliJ IDEA.
  User: mycom
  Date: 2018/3/26
  Time: 11:57
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/loginUserInfoPath/happy" method="post">
    用户名：<input name="username"/>
    <input type="submit" value="提交">

</form>
</body>
</html>