Question

我刚开始使用spring mvc而且我正在按照http://docs.spring.io/docs/Spring-MVC-step-by-step/中详述的示例进行操作，但是当我尝试运行它时，我会在本评论的末尾描述一个异常。我一直在做一些研究，但我找不到这个问题的答案。有谁知道我做错了什么？

<?xml version="1.0" encoding="UTF-8"?>

<beans:beans xmlns="http://www.springframework.org/schema/mvc"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:beans="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
        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">

    <!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->

    <!-- Enables the Spring MVC @Controller programming model -->
    <annotation-driven />

    <!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
    <resources mapping="/resources/**" location="/resources/" />

    <!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
    <beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <beans:property name="prefix" value="/WEB-INF/views/" />
        <beans:property name="suffix" value=".jsp" />
    </beans:bean>

    <context:component-scan base-package="springDemo.controller" />

    <beans:bean id="productManager" class="springDemo.service.SimpleProductManager">
        <beans:property name="products">
            <beans:list>
                <beans:idref bean="product1"/>
                <beans:idref bean="product2"/>
                <beans:idref bean="product3"/>
            </beans:list>
        </beans:property>
    </beans:bean>

    <beans:bean id="product1" class="springDemo.domain.Product">
        <beans:property name="description" value="Lamp"/>
        <beans:property name="price" value="5.75"/>
    </beans:bean>

    <beans:bean id="product2" class="springDemo.domain.Product">
        <beans:property name="description" value="Table"/>
        <beans:property name="price" value="75.25"/>
    </beans:bean>

    <beans:bean id="product3" class="springDemo.domain.Product">
        <beans:property name="description" value="Chair"/>
        <beans:property name="price" value="22.79"/>
    </beans:bean>

    <beans:bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
        <beans:property name="basename" value="messages"/>
    </beans:bean>

</beans:beans>

当我尝试运行此功能时，我会遇到此异常

java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [springDemo.domain.Product] for property 'products[0]': no matching editors or conversion strategy found
    at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:241)
    at org.springframework.beans.TypeConverterDelegate.convertToTypedCollection(TypeConverterDelegate.java:541)
    at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:179)
    at org.springframework.beans.BeanWrapperImpl.convertIfNecessary(BeanWrapperImpl.java:470)
    at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:516)
    at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:510)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty(AbstractAutowireCapableBeanFactory.java:1406)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1365)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1118)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
    at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:631)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:588)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:645)
    at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:508)
    at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:449)
    at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:133)
    at javax.servlet.GenericServlet.init(GenericServlet.java:158)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1284)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1197)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:864)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:134)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)

更新：我忘了提及，我已经安装了Spring Tool Suite 3.6.1并且我已经创建了一个spring web项目。

Answer 1

我认为您必须从表单输入产品，因此Spring无法将输入字符串转换为产品类型。为此，你必须编写一个属性编辑器。

属性编辑器允许您在实例产品及其字符串表示形式的自定义对象之间进行转换。

异常告诉Spring无法自动将POST字符串值转换为实际的“product”对象。

检查spring property editor

如何在spring mvc中定义bean

1 个答案: