[Framework] Etat HTTP 500 - Request processing failed; nested exception is java.lang.NullPointerException

Bonjour,

Ci-dessous l'erreur que j'obtiens lorsque j'essaie d'envoyer un fichier avec spring mvc

Etat HTTP 500 - Request processing failed; nested exception is java.lang.NullPointerException

J'ai une idée de l'origine de l'erreur mais toutes mes tentatives pour la résoudre sont restées vaines.

Merci de bien vouloir m'aider à comprendre ce qui ne marche pas dans mon code

Retrouvez ci dessous mes codes.

FileModel.java

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
package com.model;
 
import org.springframework.web.multipart.MultipartFile;
 
public class FileModel {
 
	private MultipartFile file;
 
	public MultipartFile getFile() {
		return file;
	}
 
	public void setFile(MultipartFile file) {
		this.file = file;
	}
}

FileUploadController.java

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
package com.controller;
 
import java.io.File;
import java.io.IOException;
 
import javax.servlet.ServletContext;
 
import org.jboss.logging.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.util.FileCopyUtils;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.ModelAndView;
 
import com.model.FileModel;
 
@Controller
public class FileUploadController {
 
	public Logger logger = Logger.getLogger(FileUploadController.class);
 
	public FileUploadController(){
		System.out.println("FileUploadController");
	}
 
	@Autowired
	private ServletContext context;
 
	@RequestMapping(value="/uploadpage", method=RequestMethod.GET)
	public ModelAndView UploadPage(ModelAndView model){
		FileModel fileModel = new FileModel();
		model.addObject("fileModel", fileModel);
		model.setViewName("upload_page");
		return model;
	}
 
	@RequestMapping(value="/uploadpage", method=RequestMethod.POST)
	public ModelAndView UploadPage(@ModelAttribute("filemodel") FileModel fileModel, BindingResult result, ModelAndView model) throws IOException{		
		if(result.hasErrors()){
			System.out.println("validation errors");
			model.addObject("fileModel", fileModel);
			model.setViewName("upload_page");
			return model;
		}else{
			String path = context.getRealPath("") + File.separator + "fichiers" + File.separator;
			System.out.println(path);
			MultipartFile file = fileModel.getFile();
			System.out.println(file);
			String filename = file.getOriginalFilename();
			System.out.println(filename);
			FileCopyUtils.copy(file.getBytes(), new File(path+filename));
			model.addObject("filename", filename);
			model.setViewName("upload_page");
			return model;
		}
	}
}

upload_page.jsp

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1" isELIgnored="false"%>
<%@ taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
 
<!DOCTYPE html>
<html>
	<head>
		<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
		<title>Upload</title>
	</head>
	<body>		
		<form:form modelAttribute = "filemodel" method = "post" action="uploadpage" enctype = "multipart/form-data">
			<input type = "file" name = "file" />
			<input type = "submit" value = "upload" />
		</form:form>
 
		FileName : <b> ${filename} </b> - Uploaded Successfully.
	</body>
</html>

Message affiché dans la console

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
nov. 02, 2017 11:55:37 AM org.apache.catalina.core.StandardWrapperValve invoke
GRAVE: Servlet.service() for servlet [spring] in context with path [/oracle_spring_user_test_project] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause
java.lang.NullPointerException
	at com.controller.FileUploadController.UploadPage(FileUploadController.java:53)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:777)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:706)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:943)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
	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.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:962)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1115)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:745)