Spring REST controller file upload - Request method 'POST' not supported error - spring

Question

I'm in the process of creating a prototype for a web app, where one of the functions should allow someone to upload an excel file with some extra info. The file alongside the info is stored in an object, which is serialized and stored.
I have created the upload method, and while trying to test the function it throws the "Request method 'POST' not supported" whitelabel error page.
I have suspicions that it might be the pom.xml at fault, but I'm not entirely sure.
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>project</groupId>
<artifactId>answers</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<name>MVC 1.0 Blank Project (from https://github.com/making/mvc-1.0-blank)</name>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-web-api</artifactId>
<version>7.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.glassfish.ozark</groupId>
<artifactId>ozark</artifactId>
<version>1.0.0-m02</version>
</dependency>
<!-- Swing exercise -->
<dependency>
<groupId>com.miglayout</groupId>
<artifactId>miglayout</artifactId>
<version>3.5.5</version>
</dependency>
<!-- Web exercise -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.3.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.3.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-autoconfigure</artifactId>
<version>1.3.6.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>1.3.6.RELEASE</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.3</version>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
</plugins>
</build>
</project>
Here is the Controller class. We will move to a Thymeleaf configuration in a day or two, this html is just for testing purposes currently.
#MultipartConfig
#RestController
#RequestMapping(value = "/Teacher", produces = "text/html;charset=UTF-8")
public class Teacher {
#GetMapping("")
#ResponseBody
TestController testcont;
public String homePage(#RequestParam(value = "file", required = false) String name, HttpServletRequest request,
HttpServletResponse response){
StringBuilder sb = new StringBuilder();
sb.append("<p> <a href='/Teacher/NewTest'>New Test upload</a></p>\n"
+ "<p><a href='/SelectTest'>Select Test File</a> <button type='button'>Send Test</button></p>"
+ "\n \n \n"
+ "<p><a>Current Test for students:</a>\n <a href='/getCurrentTest'></a></p>"
);
return sb.toString();
}
#GetMapping("/NewTest")
#ResponseBody
public String newTestUpload(HttpServletRequest request, HttpServletResponse response){
StringBuilder sb = new StringBuilder();
if(!request.getParameterNames().hasMoreElements()){
sb.append("<p><form action='' method='post' enctype='multipart/form-data'>"
+ "<label>Enter file</label><input type='file' name='file'>"
+ "<button type='submit'>Upload</button></p>"
+ "<p><form action='/testName'>Test Name: <input type='text' name='name' value=''></p>"
+ "<p><form action='/addInfo'>Comment: <input type='text' comment='comment' value=''></p>"
+ "<p>Answer 1: <input type='text' Answer='answer1' value=''></p>"
+ "<p>Answer 2: <input type='text' Answer='answer2' value=''></p>"
+ "</form>"
+ "<a href='/Teacher'>Back</a>\n"
);
return sb.toString();
}
else if(request.getParameter("file") != null && request.getParameter("name") != ""
&& request.getParameter("comment") != "" && request.getParameter("answer1") != null
&& request.getParameter("answer2") != null){
try{
// Upload happens here
Part filePart = request.getPart("file");
String fileName = Paths.get(filePart.getSubmittedFileName()).getFileName().toString();
InputStream fileContent = filePart.getInputStream();
File testExcel = new File(fileName);
testExcel.createNewFile();
Files.copy(fileContent, Paths.get(testExcel.getName()), StandardCopyOption.REPLACE_EXISTING);
double ans1 = Double.parseDouble(request.getParameter("answer1"));
double ans2 = Double.parseDouble(request.getParameter("answer2"));
Test test = new Test(testExcel, request.getParameter("name"),
request.getParameter("comment"), ans1, ans2);
testcont.addTest(test);
sb.append("New test uploaded!<br/>\n<a href='/'>Back</a>\n");
return sb.toString();
} catch (Exception e){
sb.append("<h1>Couldnt insert test</h1>");
response.setStatus(HttpServletResponse.SC_OK);
return sb.toString();
}
}
else{
sb.append("failed<br/>\n<a href='/'>Back</a>\n");
response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
return sb.toString();
}
}
}

Answer 1

From the controller code you've posted, both of your endpoints are GET.
/Teacher :- #GetMapping
/Teacher/NewTest :- #GetMapping
You are trying to POST to an endpoint which does not support POST method, which is why you see error message, specifying 'POST' method not supported.

Answer 2

Both methods in your controller has #GetMapping annotation, that means that they support GET requests. You need to replace one with #PostMapping(to support POST requests)

Answer 3

Correct your method to:
#PostMapping
#RequestMapping("/NewTest")
public String newTestUpload(HttpServletRequest request, HttpServletResponse response) {
or
#PostMapping(path = "/NewTest")
public String newTestUpload(HttpServletRequest request, HttpServletResponse response) {