SpringMVC自定义数据类型转换器

一时失言乱红尘 2022-11-07 01:56 176阅读 0赞

### 要解决的问题 ###

springMVC自带了很多自动的数据类型转换器，比如String转Integer，String转Date等，但在String转Date中，2021-01-01无法自动转为Date，所以就需要我们自定义一个数据类型转换类；

### 步骤 ###

1、写一个String转Date的转换类，该类实现Converter接口，并复写其中的convert方法

package cn.gpxxg.utils.converter;
    
    import org.springframework.core.convert.converter.Converter;
    
    import java.text.DateFormat;
    import java.text.ParseException;
    import java.text.SimpleDateFormat;
    import java.util.Date;
    
    /**
     * 类型转换，把String转为Date
     */
    public class StringToDate implements Converter<String, Date> {
        @Override
        public Date convert(String s) {
            if (s == null)
                throw new RuntimeException("请您传入数据");
    
            DateFormat date = new SimpleDateFormat("yyyy-MM-dd");
            Date parse = null;
            try {
                parse = date.parse(s);
            } catch (ParseException e) {
                e.printStackTrace();
            }
            return parse;
        }
    }

2、在springmvc配置文件中配置自定义类型转换器，注入ConversionServiceFactoryBean并加入我们自定义的转换类，并在mvc:annotation-driven中开启自定义类型转换的支持

<?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.xsd">
    
        
        <context:component-scan base-package="cn.gpxxg"></context:component-scan>
    
        
        <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            
            <property name="prefix" value="/WEB-INF/pages/"></property>
    
            
            <property name="suffix" value=".jsp"></property>
        </bean>
    
        
        <bean id="conversionServiceFactoryBean" class="org.springframework.context.support.ConversionServiceFactoryBean">
            <property name="converters">
                <set>
                    <bean class="cn.gpxxg.utils.converter.StringToDate"></bean>
                </set>
            </property>
        </bean>
    
        
        <mvc:annotation-driven conversion-service="conversionServiceFactoryBean"/>
    </beans>

3、写个页面自测吧

![20210310181155602.png][]

[20210310181155602.png]: /images/20221023/75101a83f1184cb39fb4d9d44a147420.png