• SpringMVC(十四)类型转换器


    为什么页面上输入‘12’,可以复制给Handler方法对应的参数?

    和是因为类型转换器并不是可以将用户提交的String,转换为用户需要的所有类型,此时,就需要自定义类型转换器可

    案例:自定义日期类型转换器   要求格式:yyyy/MM/dd

    页面上:

    <%--
      Created by IntelliJ IDEA.
      User: mycom
      Date: 2018/3/26
      Time: 11:57
      To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
    <html>
    <head>
        <title>Title</title>
    </head>
    <body>
    <h2>登录</h2>
    <form action="${pageContext.request.contextPath}/first" method="post">
        用户名:<input type="text" name="name" value="${name}"/>
        年龄:<input type="text" name="age" value="${age}"/>
        出生日期:<input type="text" name="birthday"/>
        <input type="submit" value="提交">
    </form>
    </body>
    </html>

    控制器类

    package demo16TypeConverter;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.ExceptionHandler;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.servlet.ModelAndView;
    
    import javax.servlet.http.HttpServletRequest;
    import java.util.Date;
    
    /**
     * Created by mycom on 2018/3/30.
     */
    @Controller
    public class TypeController {
    
        @ExceptionHandler
        public ModelAndView doSome(Exception ex, HttpServletRequest request){
            ModelAndView mv=new ModelAndView();
            mv.addObject("name",request.getAttribute("name"));
            mv.setViewName("login");
            mv.addObject("ex",ex);//保存的数据,在页面上用EL表达式展示错误信息
            //判断异常类型
            if(ex instanceof NameException){
                mv.setViewName("nameException");
            }
            if(ex instanceof AgeException){
                mv.setViewName("ageException");
            }
            return mv;
        }
    
        @RequestMapping("/first")
        public String doFirst(String name, int age, Date birthday){
            System.out.println(name);
            System.out.println(age);
            System.out.println(birthday);
            return "success";
        }
    }

    配置文件中

    <?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:mvc="http://www.springframework.org/schema/mvc"
           xmlns:context="http://www.springframework.org/schema/context"
           xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    
        <context:component-scan base-package="demo16TypeConverter"></context:component-scan>
    
        <!--视图解析器-->
        <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            <property name="prefix" value="/error/"></property>
            <property name="suffix" value=".jsp"></property>
        </bean>
    
        <!--配置自定义的转换器-->
        <bean id="MyConverter" class="demo16TypeConverter.MyConverter"></bean>
    
        <!--注册一个转换器-->
        <bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
            <property name="converters" ref="MyConverter"></property>
        </bean>
    
        <!--注解驱动-->
        <mvc:annotation-driven conversion-service="conversionService"></mvc:annotation-driven>
    
    
    
    
    </beans>

    自定义类型转化器

    package demo16TypeConverter;
    
    import org.springframework.core.convert.converter.Converter;
    
    import java.text.ParseException;
    import java.text.SimpleDateFormat;
    import java.util.Date;
    import java.util.regex.Pattern;
    
    /**
     * Created by mycom on 2018/3/30.
     */
    public class MyConverter implements Converter<String,Date> {
    
        public Date convert(String str) {
            SimpleDateFormat sdf=getConverter(str);
            try {
                Date date=sdf.parse(str);
                return date;
            } catch (ParseException e) {
                e.printStackTrace();
            }
            return null;
        }
    
        private SimpleDateFormat getConverter(String str) {
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日");
         //匹配不同的格式
    if(Pattern.matches("^\d{4}-\d{2}-\d{2}$",str)){ sdf = new SimpleDateFormat("yyyy-MM-dd"); }else if(Pattern.matches("^\d{4}/\d{2}/\d{2}$",str)){ sdf = new SimpleDateFormat("yyyy/MM/dd"); }else if(Pattern.matches("^\d{4}\d{2}\d{2}$",str)){ sdf = new SimpleDateFormat("yyyyMMdd"); } return sdf; } }

     配置文件和页面还是使用的上面的一种

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  • 原文地址:https://www.cnblogs.com/my-123/p/8681637.html
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