mvc custom date converter

1. Configure the encoding filter

1. Set and configure the encoding filter provided by spring mvc in web.xml to solve the problem of garbled data submitted by get/post

  <!--配置编码过滤器-->
  <filter>
    <filter-name>characterEncodingFilter</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>utf-8</param-value>
    </init-param>
  </filter>

  <filter-mapping>
    <filter-name>characterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

2. Get request parameters, parameter binding annotations

http://127.0.0.1:8080/spring_mvc_01/user/save13?name=123

    /**
     * 利用name来映射username
     * required false 可不提供参数，否则400
     * @param username
     */
    @RequestMapping(value = "/save13")
    @ResponseBody
    public void save13(@RequestParam(value = "name", defaultValue = "bitqian", required = false) String username) {
    
    
        System.out.println(username);
    }

3. Get request parameters, custom type converter

实现步骤：
1. 定义转换器类实现converter接口
2. 在配置文件中声明转换器
3. 在，<annotation-driven>中引用转换器

1. Custom date converter

package com.bitqian.convertor;

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

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

/**
 * 自定义日期转换器
 * @author echo lovely
 * @date 2020/9/2 22:01
 */
public class DateConverter implements Converter<String, Date> {
    
    

    @Override
    public Date convert(String s) {
    
    

        List<DateFormat> dateList = new ArrayList<>();
        dateList.add(new SimpleDateFormat("yyyy-MM-dd"));
        dateList.add(new SimpleDateFormat("yyyy/MM/dd"));
        dateList.add(new SimpleDateFormat("yyyy.MM.dd"));

        Date date = null;
        for (int i = 0; i < dateList.size(); i++) {
    
    
            try {
    
    
                // 支持 -- // ..日期格式的转换
                date = dateList.get(i).parse(s);

                return date;
            } catch (ParseException e) {
    
    
                // e.printStackTrace();
                continue;
            }
        }

        return null;
    }


    public static void main(String[] args) {
    
    
        DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd");
        try {
    
    
            Date date = dateFormat.parse("2020/4/4");
            System.out.println(date);
        } catch (ParseException e) {
    
    
            e.printStackTrace();
        }
    }
}

2. Spring mvc configuration

        <mvc:annotation-driven conversion-service="conversionServiceFactoryBean"/>

        <!--日期转换器-->
        <bean id="conversionServiceFactoryBean"
              class="org.springframework.context.support.ConversionServiceFactoryBean">
                <property name="converters">
                        <list>
                                <bean class="com.bitqian.convertor.DateConverter"></bean>
                        </list>
                </property>
        </bean>

3. Test date converter

    /**
     * 测试日期转换器
     */
    @RequestMapping(value = "/save14")
    @ResponseBody
    public void save14(Date date) {
    
    
        System.out.println(date);
    }