Spring MVC 数据绑定

数据绑定

将HTTP请求中的参数绑定到Handler业务方法的形参。（传统request方式只能传String类型，不支持对象的传递，需要先通过request获取form表单中的各个属性，再将值赋值给对象。不够灵活）

• 通过HttpMessageConverter进行数据类型转换和对象封装

  
  
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package com.imooc.controller;

import com.imooc.dao.CourseDAO;
import com.imooc.entity.Course;
import com.imooc.entity.CourseList;
import com.imooc.entity.CourseMap;
import com.imooc.entity.CourseSet;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;

/**
 * Created by Administrator.
 */
@Controller
public class DataBindController {

    @Autowired
    private CourseDAO courseDAO;

    //配置路径，相当于在servlet中配置了
    @RequestMapping(value = "/baseType")
    //ResponseBody 直接返回当前页面
    @ResponseBody
    public String baseType(@RequestParam(value = "id") int id){
        return "id:"+id;
    }

    @RequestMapping(value = "/packageType")
    @ResponseBody
    public String packageType(@RequestParam(value = "id") Integer id){
        return "id:"+id;
    }

    @RequestMapping(value = "/arrayType")
    @ResponseBody
    public String arrayType(String[] name){
        StringBuffer sbf = new StringBuffer();
        for (String item:name){
            sbf.append(item).append(" ");
        }
        return sbf.toString();
    }

    @RequestMapping(value = "/pojoType")
    public ModelAndView pojoType(Course course){
        courseDAO.add(course);
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("index");
        modelAndView.addObject("courses",courseDAO.getAll());
        return modelAndView;
    }



    //List集合,不能直接使用List<Course>,需要定义包装类
    @RequestMapping(value = "/listType")
    public ModelAndView listType(CourseList courseList){

        for(Course course:courseList.getCourses()){
            courseDAO.add(course);
        }
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("index");
        modelAndView.addObject("courses",courseDAO.getAll());
        return modelAndView;
    }


    @RequestMapping(value = "/mapType")
    public ModelAndView mapType(CourseMap courseMap){
        for (String key:courseMap.getCourses().keySet()){
            Course course = courseMap.getCourses().get(key);
            courseDAO.add(course);
        }

        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("index");
        modelAndView.addObject("courses",courseDAO.getAll());
        return modelAndView;
    }

    @RequestMapping(value = "/setType")
    public ModelAndView setType(CourseSet courseSet){
        for (Course course:courseSet.getCourses()){
            courseDAO.add(course);
        }
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("index");
        modelAndView.addObject("courses",courseDAO.getAll());
        return modelAndView;
    }

    @RequestMapping(value = "/jsonType")
    @ResponseBody
    public  Course jsonType(@RequestBody  Course course){
        course.setPrice(course.getPrice()+100);
        return course;
    }



}

• 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"
       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.xsd
       http://www.springframework.org/schema/mvc
       http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">

    <context:component-scan base-package="com.imooc"></context:component-scan>

    <mvc:annotation-driven>
        <mvc:message-converters>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"></bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

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

</beans>