springmvc + form:form 上传文件配置。

前几天写了springmvc form 表单，今天在form的基础上，加 上传文件配置。

需要在，springmvc-config.xml中进行配置上传文件。

<!-- 上传文件配置 Configure the multipart resolver -->
	<bean id="multipartResolver"
		class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
		<!-- one of the properties available; the maximum file size in bytes -->
		<property name="defaultEncoding" value="UTF-8" />
		<property name="maxUploadSize" value="209715200" />
		<!-- 20M -->
		<!-- 要在WebContent下建立一个upload文件夹 <property name="uploadTempDir" value="upload"/> -->
	</bean>

在参数类中，加  

private File txtFile = null;

并加上get.set 方法。

jsp 的form中，

<form:input type="file" path="txtFile"/>

后天controller就可以获取File对象了。

如果获取的 文件 名称乱码，则在web.xml中进行配置 编码Filter。

http://blog.csdn.net/u012246342/article/details/52190910

遇到一个BUG，

原因是，在参数的form中， 最开始并不是用File，而是用 import org.springframework.web.multipart.commons.CommonsMultipartFile;

的  CommonsMultipartFile，所以报错如下：

严重: Servlet.service() for servlet springmvc threw exception
org.springframework.validation.BindException: org.springframework.validation.BeanPropertyBindingResult: 1 errors
Field error in object 'textLoginForm' on field 'txtFile': rejected value [Editorial_流程任务库_委托创作合同审核.xlsx]; codes [typeMismatch.textLoginForm.txtFile,typeMismatch.txtFile,typeMismatch.org.springframework.web.multipart.commons.CommonsMultipartFile,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [textLoginForm.txtFile,txtFile]; arguments []; default message [txtFile]]; default message [Failed to convert property value of type 'java.lang.String' to required type 'org.springframework.web.multipart.commons.CommonsMultipartFile' for property 'txtFile'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.commons.CommonsMultipartFile] for property 'txtFile': no matching editors or conversion strategy found]
	at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.doBind(HandlerMethodInvoker.java:818)
	at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolveHandlerArguments(HandlerMethodInvoker.java:367)
	at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:171)
	at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:436)
	at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:424)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:643)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:861)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:612)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:503)
	at java.lang.Thread.run(Unknown Source)

类型错误，org.springframework.validation.BindException，类型转换错误。