0023SpringMVC自定义类型转换器

页面录入的字符串：2019/12/05可以映射到实体的日期属性上，但是如果是录入2019-12-05就会报错400 bad request，想要以2019-12-05日期格式的方式映射到实体的日期属性上，需要自定义类型转换器，主要步骤如下：

1、  自定义类实现Convertro<S,T>接口

2、Springmvc.xml中配置ConversionServiceFactoryBean，其属性上配置我们自定义的转换器

3、欲使配置的转换器生效，需要将springmvc.xml的<mvc:annotation-driven />改为

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

1、  自定义类实现Convertro<S,T>接口

package com.example.util;

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

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

public class StingToDateConvertr implements Converter<String, Date> {    @Override    public Date convert(String s) {        if(StringUtils.isEmpty(s)){            throw new RuntimeException("日期字符串不能为空！");        }        DateFormat df = new SimpleDateFormat("yyyy-MM-dd");        try {            return df.parse(s);        } catch (ParseException e) {            throw new RuntimeException("类型转换出错！");        }    }}

2、Springmvc.xml中配置ConversionServiceFactoryBean，其属性上配置我们自定义的转换器

<!--配置自定义类型转换器--><bean id="conversionServiceFactoryBean" class="org.springframework.context.support.ConversionServiceFactoryBean">    <property name="converters">        <set>            <bean class="com.example.util.StingToDateConvertr" />        </set>    </property></bean>

3、欲使配置的转换器生效，需要将springmvc.xml的<mvc:annotation-driven />改为

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

springmvc.xml的完整配置如下：

<?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:aop="http://www.springframework.org/schema/aop"       xmlns:c="http://www.springframework.org/schema/c"       xmlns:cache="http://www.springframework.org/schema/cache"       xmlns:context="http://www.springframework.org/schema/context"       xmlns:jdbc="http://www.springframework.org/schema/jdbc"       xmlns:jee="http://www.springframework.org/schema/jee"       xmlns:lang="http://www.springframework.org/schema/lang"       xmlns:mvc="http://www.springframework.org/schema/mvc"       xmlns:p="http://www.springframework.org/schema/p"       xmlns:task="http://www.springframework.org/schema/task"       xmlns:tx="http://www.springframework.org/schema/tx"       xmlns:util="http://www.springframework.org/schema/util"       xsi:schemaLocation="http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.3.xsd      http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd      http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd      http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd      http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd      http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-4.3.xsd      http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache-4.3.xsd      http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-4.3.xsd      http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd      http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-4.3.xsd      http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd ">    <!--开启注解扫描-->    <context:component-scan base-package="com.example" />    <!--视图解析器，根据Controller返回的字符串找对应的文件-->    <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">        <!--文件路径-->        <property name="prefix" value="/WEB-INF/pages/" />        <!--文件后缀-->        <property name="suffix" value=".jsp" />    </bean>    <!--配置自定义类型转换器-->    <bean id="conversionServiceFactoryBean" class="org.springframework.context.support.ConversionServiceFactoryBean">        <property name="converters">            <set>                <bean class="com.example.util.StingToDateConvertr" />            </set>        </property>    </bean>

    <!--1、开启springmvc框架注解的支持-->    <!--2、欲使配置的自定义类型转换器生效，需加上conversion-service属性-->    <mvc:annotation-driven conversion-service="conversionServiceFactoryBean"/>

</beans>

注意：自定义的类型转换器生效之后，日期格式就只能使用yyyy-MM-dd的格式了，若再使用原有的yyyy/MM/dd格式就会报错！

如有理解不到之处，望指正！

原文地址：https://www.cnblogs.com/xiao1572662/p/11988489.html