springmvc包含文件上傳的表單報錯

錯誤出現

報錯內容

嚴重: Servlet.service() for servlet [SpringMVC] in context with path [/test_online] threw exception [Request processing failed; nested exception is java.lang.IllegalStateException: Optional int parameter 'chno' is present but cannot be translated into a null value due to being declared as a primitive type. Consider declaring it as object wrapper for the corresponding primitive type.] with root cause
java.lang.IllegalStateException: Optional int parameter 'chno' is present but cannot be translated into a null value due to being declared as a primitive type. Consider declaring it as object wrapper for the corresponding primitive type.
	at org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver.handleNullValue(AbstractNamedValueMethodArgumentResolver.java:188)
	at org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver.resolveArgument(AbstractNamedValueMethodArgumentResolver.java:94)
	at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:77)
	at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:157)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:124)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:953)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:855)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:829)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
	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)

報錯操作

點擊“添加問題”按鈕後，按規範輸入所需字段，點擊確定後，後臺就會報錯。報錯原因如上。

錯誤分析

流程分析

包含文件上傳的ssm框架。

首先要在前臺提交的form表單加上 enctype

<form  id='singleForm' method="post" enctype="multipart/form-data">
	
		<!-- 其他代碼 -->
		
		<div  style="width:100%;margin-top:3px;">
			<font size="2">試題內容：</font> 
			<input type="text" id="stext" name="stext"/>
		</div>
		
		
		<div  style="width:100%;margin-top:3px;">
			<font size="2">試題圖片：</font> 
			<!-- 試題圖片：默認沒有 -->
			<input type="text" id="simg" name="simg"/>
		</div>
		<!-- 其他代碼 -->		
	</form>

然後在我們的controller中使用 MultipartFile接收我們的文件

	@RequestMapping("/addSingle.do")
	@ResponseBody
	public void addSingle(int chno,int stype,String stext,MultipartFile simg, int sanswer,String[] soptions,HttpServletRequest request){
		
		//業務流程代碼
		
	}

流程正常運行後，所有的屬性都會獲取到，但是我們這裏確實報錯了！！

經仔細查詢，錯誤原因是因爲：沒有在springmvc的配置文件裏，配置文件上傳的bean。

解決辦法

錯誤原因是因爲：沒有在springmvc的配置文件裏，配置文件上傳的bean。

1.首先在springmvc的配置文件裏，配置文件上傳的bean

 <!-- 配置文件上傳，引入上傳組件包 -->  
    <bean id="multipartResolver"    
        class="org.springframework.web.multipart.commons.CommonsMultipartResolver">    
        <!-- 默認編碼 -->  
        <property name="defaultEncoding" value="utf-8" />    
        <!-- 文件大小最大值 -->  
        <property name="maxUploadSize" value="10485760000" />    
        <!-- 內存中的最大值 -->  
        <property name="maxInMemorySize" value="40960" />    
    </bean>   
    

2.引人上傳組件包

因爲springmnv的文件上傳，依賴於Apache的文件上傳，需要導入jar包：點擊下載

成功