SpringMvc中初始化参数绑定

初始化参数绑定与类型转换很类似，初始化绑定时，主要是参数类型

---单日期

在处理器类中配置绑定方法  使用@InitBinder注解

在这里首先注册一个用户编辑器 参数一为目标类型   propertyEditor为属性编辑器，此处我们选用 CustomDateEditor属性编辑器，

参数一为想转换的日期格式，参数二表示是否允许为空

package cn.controller;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 *
 * @author 景佩佩
 *
 */
@Controller
public class MyController{
     //处理器方法
    @RequestMapping(value="/first.do")
    public String doFirst(Date birthday,int age) {
        System.out.println("3333");
        return "/welcome.jsp";
    }

    //自定义一个方法
    @InitBinder
    public void initBinder(WebDataBinder binder){
        DateFormat df=new SimpleDateFormat("yyyy-MM-dd");
        binder.registerCustomEditor(Date.class, new CustomDateEditor(df, true));
    }

}

只需在applicationContext.xml配置一个包扫描器就行

<?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:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx"
    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/aop http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
        ">

     <!-- 包扫描器 -->
     <context:component-scan base-package="cn.controller"></context:component-scan>

</beans>

index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    <style type="text/css">
       form{
        background-color:pink;
         width:500px;
       }
    </style>
    <title></title>
  </head>

  <body>
    ${ex.message }
    <form action="${pageContext.request.contextPath }/first.do" method="post">
    <h1>自定义类型转换器</h1>
                 出生日期:<input name="birthday" value="${birthday }"/>${birthdayerror }<br/><br/>
                 年龄:<input name="age" value="${age }"/>${ageerror }<br/><br/>
       <input type="submit" value="注册"/>
    </form>
  </body>
</html>

welcome.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">

    <title>欢迎页面</title>

  </head>

  <body>
     <h1>欢迎访问${uname }${param.uage }</h1>
  </body>
</html>

---

---多日期格式

配置步骤：

在处理器类中使用我们自定的属性编辑器

MyController.java

package cn.controller;

import java.util.Date;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class MyController{
     //处理器方法
    @RequestMapping(value="/first.do")
    public String doFirst(Date birthday,int age) {
        System.out.println("3333");
        return "/welcome.jsp";
    }

    //自定义一个方法
    @InitBinder
    public void initBinder(WebDataBinder binder){
        System.out.println("==========");
        binder.registerCustomEditor(Date.class, new MyDateEditor());
    }

}

属性编辑器

此时我们需要考虑使用哪个属性编辑器，需要定义自己的属性编辑器

大致的配置方式如单日期相似，只需要更换属性编辑即可

自定义的属性编辑器，需要我们继承PropertiesEditor，重写里面的setAsText方法，使用setValue方法赋值

MyDateEditor.java

package cn.controller;

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

import org.springframework.beans.TypeMismatchException;
import org.springframework.beans.propertyeditors.PropertiesEditor;
/**
 *
 * @author 景佩佩
 *
 */
public class MyDateEditor extends PropertiesEditor{

    /**
     * source:字符串型的日期
     */
    @Override
    public void setAsText(String source) throws IllegalArgumentException {
        //一旦报错，自动调度到异常处理器
        SimpleDateFormat sdf=getDateFormat(source);

        try {
             Date date = sdf.parse(source);

             setValue(date);
        } catch (ParseException e) {
            e.printStackTrace();
        }
    }

    private SimpleDateFormat getDateFormat(String source){

        SimpleDateFormat sdf=new SimpleDateFormat();
        if (Pattern.matches("^\\d{4}-\\d{2}-\\d{2}$", source)) {
            sdf=new SimpleDateFormat("yyyy-MM-dd");
        }else if (Pattern.matches("^\\d{4}/\\d{2}/\\d{2}$", source)) {
            sdf=new SimpleDateFormat("yyyy/MM/dd");
        }else if (Pattern.matches("^\\d{4}\\d{2}\\d{2}$", source)) {
            sdf=new SimpleDateFormat("yyyyMMdd");
        }else {
            throw new TypeMismatchException("",Date.class);
        }
        return sdf;
    }
}