upload file springboot Required request part 'file' is not present

Question

I want to add an upload function to my spring boot application; this is my upload Rest Controller

package org.sid.web;

import java.io.BufferedOutputStream         


        

Answer 1

Except for other posted answers, the problem might be realated to missing multipart support for the servlet handling the request (spring's DispatcherServlet in case of Spring's app).

This can be fixed by adding multipart support to dispatcher servlet in web.xml declaration or during initialization (in case of annotation-based config)

a) web-xml based config

 
   dispatcher
   
     org.springframework.web.servlet.DispatcherServlet
   
   
     contextConfigLocation
     /WEB-INF/spring/dispatcher-config.xml
   
   1
   
        10485760
        20971520
        5242880
    
 

b) for annotation-based configuration this would be following:

public class AppInitializer implements WebApplicationInitializer { 

@Override 
public void onStartup(ServletContext servletContext) { 
    final AnnotationConfigWebApplicationContext appContext = new AnnotationConfigWebApplicationContext(); 

    final ServletRegistration.Dynamic registration = servletContext.addServlet("dispatcher", new DispatcherServlet(appContext)); 
    registration.setLoadOnStartup(1); 
    registration.addMapping("/"); 

    File uploadDirectory = new File(System.getProperty("java.io.tmpdir"));                  
    MultipartConfigElement multipartConfigElement = new  MultipartConfigElement(uploadDirectory.getAbsolutePath(), 100000, 100000 * 2, 100000 / 2); 

    registration.setMultipartConfig(multipartConfigElement);
} }

Then we need to provide multipart resolver which can resolve files sent as multipart-request. For annotation config this can be done in following way:

@Configuration
public class MyConfig {

@Bean
public MultipartResolver multipartResolver() {
    return new StandardServletMultipartResolver();
}
}

For xml-based spring configuration you need to add this bean to the context via tag declaration declaration:

Alternatively to spring's standard multipart resolver you can use implementation from commons. This way however extra dependency is required:

  commons-fileupload
  commons-fileupload
  1.3.3