参数绑定

默认支持的参数

SpringMVC 有支持的默认参数类型，我们直接在形参上给出这些默认类型的声明，就能直接使用了。如下：
　　1 HttpServletRequest 对象
　　2 HttpServletResponse 对象
　　3 HttpSession 对象
　　4 Model/ModelMap 对象

pojo类型绑定

需求：
根据学院编号查询学院。

mybatis持久层

<resultMap id="facultyCustomMap" type="com.pesystem.vo.FacultyCustom" extends="com.pesystem.mapper.FacultyMapper.BaseResultMap"/>


<select id="selectFacultyByFacultyId" resultMap="facultyCustomMap">
        SELECT
          <include refid="com.pesystem.mapper.FacultyMapper.Base_Column_List" />
        from faculty where
          faculty_id = #{facultyCustom.facultyId}
    </select>

测试mapper层代码

package com.pesystem.mapper;

import com.pesystem.vo.FacultyCustom;
import com.pesystem.vo.FacultyQueryVo;
import org.apache.log4j.Logger;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"classpath:springConfig/spring-dao.xml"})
public class FacultyCustomMapperTest {
    //获取日志记录器Logger，名字为本类类名
    private static Logger log = Logger.getLogger(String.valueOf(FacultyMapperTest.class));

    @Autowired
    private FacultyCustomMapper facultyCustomMapper;

    @Test
    public void testInsert(){
        FacultyQueryVo facultyQueryVo = new FacultyQueryVo();
        FacultyCustom facultyCustom = new FacultyCustom();
        facultyCustom.setFacultyId(3);
        facultyQueryVo.setFacultyCustom(facultyCustom);
        FacultyCustom facultyCustom1 = facultyCustomMapper.selectFacultyByFacultyId(facultyQueryVo);
        log.info(facultyCustom1);
    }
}

测试结果：

 INFO [main] - Loaded default TestExecutionListener class names from location [META-INF/spring.factories]: [org.springframework.test.context.web.ServletTestExecutionListener, org.springframework.test.context.support.DependencyInjectionTestExecutionListener, org.springframework.test.context.support.DirtiesContextTestExecutionListener, org.springframework.test.context.transaction.TransactionalTestExecutionListener, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener]
 INFO [main] - Using TestExecutionListeners: [org.springframework.test.context.web.ServletTestExecutionListener@7c16905e, org.springframework.test.context.support.DependencyInjectionTestExecutionListener@2a2d45ba, org.springframework.test.context.support.DirtiesContextTestExecutionListener@2a5ca609, org.springframework.test.context.transaction.TransactionalTestExecutionListener@20e2cbe0, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener@68be2bc2] INFO [main] - Loading XML bean definitions from class path resource [springConfig/spring-dao.xml]
 INFO [main] - Refreshing org.springframework.context.support.GenericApplicationContext@e45f292: startup date [Tue Aug 21 09:43:48 CST 2018]; root of context hierarchy
 INFO [main] - Loading properties file from class path resource [db.properties]
 INFO [main] - 3默认院系
 INFO [Thread-1] - Closing org.springframework.context.support.GenericApplicationContext@e45f292: startup date [Tue Aug 21 09:43:48 CST 2018]; root of context hierarchy

service层
接口和实现

public interface FacultyCustomService {
  
    public FacultyCustom selectFacultyByFacultyId(FacultyQueryVo facultyQueryVo);
}

    @Override
    public FacultyCustom selectFacultyByFacultyId(FacultyQueryVo facultyQueryVo){
        return facultyCustomMapper.selectFacultyByFacultyId(facultyQueryVo);
    }

这一层没有什么处理所以就忽略测试

handler

    @RequestMapping("/selectFacultyById.action")
    public ModelAndView selectFacultyById(FacultyQueryVo facultyQueryVo){
        ModelAndView modelAndView = new ModelAndView();
        FacultyCustom facultyCustom = facultyCustomService.selectFacultyByFacultyId(facultyQueryVo);
        modelAndView.setViewName("selectFaculty");
        modelAndView.addObject("facultyCustom",facultyCustom);
        return modelAndView;
    }

前端jsp

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2018/8/20
  Time: 20:36
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page isELIgnored="false" %>
<html>
<head>
    <title>综合学院条件</title>
</head>
<script src="js/jquery-3.2.1.min.js"></script>
<script>
    $(document).ready(function(){
        $("#selectFacultiesByName").click(function(){
            path="${pageContext.request.contextPath}/faculty/selectFacultiesByName.action";
            $('#facultyForm').attr("action", path).submit();
        });
        $("#selectFacultyById").click(function(){
            path="${pageContext.request.contextPath}/faculty/selectFacultyById.action";
            $('#facultyForm').attr("action", path).submit();

        });
    });
</script>
<body>
<form id="facultyForm" action="${pageContext.request.contextPath}/faculty/selectFacultiesByName.action" method="get">
    <label>查询条件</label><br/>
    <label>模糊查询名字：</label><input type="text" name="facultyCustom.facultyName"><br>
    <input type="button" value="模糊查询" name="selectFacultiesByName" id="selectFacultiesByName"><br>

    <label>精准id:</label><input type="text" name="facultyCustom.facultyId"><br>
    <input type="button" value="精准查询" name="selectFacultyById" id="selectFacultyById">
</form>

</body>
</html>

结果页面

<%@ page language="java" contentType="text/html;charset=UTF-8"
         pageEncoding="UTF-8" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ page isELIgnored="false" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <c:if test="${facultyCustom!=null}  ">
        <c:out value="${facultyCustom}"></c:out>
    </c:if>

</body>
</html>

测试结果
怎么都不能显示结果，但是去掉判断c:if之后，就能输出。可推出条件错误，发现原来是多了两个空格，导致异常。

整理之后结果：

image.png

简单类型绑定

需求：
根据学院编号查询学院。（只需要传入facultyId过来）

mapper只是controller输入参数区别比较大，这里只用mapper的单表实现。就没有测试，主要展示controller

controller

   @RequestMapping("/selectFacultyById2.action")
    public String selectFacultyById2(Model model, @RequestParam("facultyCustom.facultyId") Integer facultyId){
        Faculty faculty = facultyService.selectFacultyByFacultyId(facultyId);
        model.addAttribute("facultyCustom",faculty);
        return "selectFaculty";
    }

测试结果：

image.png

这里还发生了一个小插曲，传入参数我用成了ModelAndView导致数据一直存入不进去，还是没认真啊

这里最好使用@RequestParam因为一张form表单，我们很多时候有多种功能，如果pojo和简单类型参数一起用，肯定需要@RequestParam注解，前端设置name最好优先满足pojo~~

自定义参数绑定

需求添加学生信息：

学生信息里面包括姓名学号生日等等。主要是使用生日完成自定义参数
表现层实现：
普通的表单提交

image.png

controller层：
先不使用自定义的参数绑定

image.png

参数没有绑定成功。
自定义参数绑定实现日期类型绑定
将String 转为java.util.Date

向处理器适配器中注入自定义参数绑定组件

在controller包下面创建自定义参数绑定包,创建类。该类需要实现Converter<E，T>接口。注意导入的包

import org.springframework.core.convert.converter.Converter;

类创建详细如下：

package com.pesystem.controller.converter;

import org.springframework.core.convert.converter.Converter;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class CustomDateConverter implements Converter<String,Date> {
    @Override
    public Date convert(String s) {
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
        try {
            return simpleDateFormat.parse(s);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }
}

在处理器映射器中，我们需要注入

<mvc:annotation-driven conversion-service="conversionService"></mvc:annotation-driven>
    <!--自定义参数绑定-->
    <bean id="conversionService" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
        <property name="converters">
            <list>
                <!--创建自定义绑定-->
                <bean class="com.pesystem.controller.converter.CustomDateConverter"/>
            </list>

        </property>
    </bean>

测试结果:

image.png

参数绑定--数组

需求同时查询多个院系，只实现controller层，完成参数绑定即可。

数组和简单类型参数绑定没有太大区别，主要是controller层的形参用数组类型，前端用多选框将多个id传过就可以了。

参数绑定--List

需求批量添加学院

扩展vo类

package com.pesystem.vo;

import com.pesystem.po.Student;

import java.util.List;

public class StudentQueryVo {
    private StudentCustom studentCustom;
    private List<Student> students;

    public List<Student> getStudents() {
        return students;
    }

    public void setStudents(List<Student> students) {
        this.students = students;
    }

    public StudentCustom getStudentCustom() {
        return studentCustom;
    }

    public void setStudentCustom(StudentCustom studentCustom) {
        this.studentCustom = studentCustom;
    }
}

controller层

    @RequestMapping("/addFaculties.action")
    public ModelAndView addFaculties(FacultyQueryVo facultyQueryVo){
        System.out.println(facultyQueryVo);
        return null;
    }

jsp
最主要就是设置name的时候一定要设置好下标，当然也可通过c:foreach或者js，jquery设置name的名字。只要数组名对应，下标不错，属性正确那么还是没什么问题。

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2018/8/21
  Time: 17:33
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page isELIgnored="false" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/faculty/addFaculties.action">
    <table>
        <tr>
            <td>学院名称</td>
            <td><input type="text" name="faculties[0].facultyName"></td>
        </tr>
        <tr>
            <td>学院名称</td>
            <td><input type="text" name="faculties[1].facultyName"></td>
        </tr>
    </table>
    <button type="submit" value="提交"/>
</form>
</body>
</html>

测试结果：

image.png