I'm trying to build a controller with PatchMapping to handle multipart/form-data. POST with multipart/form-data is working fine. But PATCH request always throws MultipartException even though the request I'm sending from postman is absolutely correct. I even tried to send PATCH without file1 and file2 but still getting same issue.

build.gradle plugins and dependencies

plugins {
    id 'org.springframework.boot' version '2.4.5'
    id 'io.spring.dependency-management' version '1.0.11.RELEASE'
    id 'java'
    id 'project-report'
    id 'jacoco'
    id "org.sonarqube" version '3.3'
    id 'net.linguica.maven-settings' version '0.5'
}
dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-aop'
    implementation 'org.springframework.boot:spring-boot-starter-validation'
    implementation 'org.springframework.boot:spring-boot-starter-actuator'
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'io.micrometer:micrometer-registry-prometheus'
    implementation 'com.google.guava:guava:30.0-jre'
    implementation 'org.apache.commons:commons-lang3:3.0'
    implementation 'org.springframework.boot:spring-boot-starter-data-mongodb'
    implementation 'org.springframework.boot:spring-boot-starter-data-mongodb-reactive'
    implementation 'com.github.java-json-tools:json-patch:1.13'
    implementation 'net.logstash.logback:logstash-logback-encoder:6.6'
    implementation group: 'javax.persistence', name: 'javax.persistence-api', version: '2.2'
    implementation 'commons-io:commons-io:1.4'
    implementation 'commons-beanutils:commons-beanutils:1.9.4'
    implementation 'org.apache.httpcomponents:httpclient:4.4.1'
    implementation group: 'commons-fileupload', name: 'commons-fileupload', version: '1.4'
}

curl

curl --location --request PATCH 'http://localhost:8443/employeeapp/v1/employees/4002494283' \
--header 'X-GP-Request-Id: $3bfc8e1c-ec2f-4d4b-8a82-f856037cb1e4' \
--header 'Content-Type: multipart/form-data' \
--form 'update_request="{
  \"emp_attributes\":[
      {
         \"name\":\"dept_id\",
         \"value\":\"123\"
      },
      {
         \"name\":\"email\",
         \"value\":\"[email protected]\"
      }
   ],
   \"user_name\":\"[email protected]\"
}"' \
--form 'file1=@"/file1.txt"' \
--form 'file2=@"/file2.txt"'

Main.java

public class Main {
    public static void main(String[] args) {
        SpringApplication.run(Main.class, args);
    }
    @Bean(name = "multipartResolver")
    public CommonsMultipartResolver multipartResolver() {
        return new CommonsMultipartResolver();
    }
}

controller

@PatchMapping(path="/"   EMP_ID_REGEX, consumes = {MediaType.MULTIPART_FORM_DATA_VALUE}, produces = {MediaType.APPLICATION_JSON_VALUE})
    public ResponseEntity<Employee> updateEmployee(@RequestHeader("X-GP-Request-Id") String UUID,
                                                             @PathVariable ("empId") String empId,
                                                             @Valid @RequestPart("update_request") UpdateRequest updateRequest,
                                                             @RequestPart(value ="file1", required = false) MultipartFile file1,
                                                             @RequestPart(value ="file2", required = false) MultipartFile file2
    ) throws Exception {}

I don't get why POST with the same data is working but PATCH is not working. Am I missing something at application level?

CodePudding user response：

You have need to modify your curl request.

curl --location --request PATCH 'http://localhost:8443/employeeapp/v1/employees/4002494283' \
--header 'X-GP-Request-Id: $3bfc8e1c-ec2f-4d4b-8a82-f856037cb1e4' \
--header 'Content-Type: multipart/form-data' \
--form 'update_request="{
  \"emp_attributes\":[
      {
         \"name\":\"dept_id\",
         \"value\":\"123\"
      },
      {
         \"name\":\"email\",
         \"value\":\"[email protected]\"
      }
   ],
   \"user_name\":\"[email protected]\"
}";type=application/json' \
--form 'file1=@"/file1.txt"' \
--form 'file2=@"/file2.txt"'

It works for me. Issue with your curl request controller not able to resolve json request part body.

Also For me without type=application/json post is also not working.

CodePudding user response：

Class CommonsMultipartResolver has an isMultipart method which determines whether the request contains multipart content. This method returns false if the request is not a POST.

Here's its code:

if (!POST_METHOD.equalsIgnoreCase(request.getMethod())) {
    return false;
}
return FileUploadBase.isMultipartContent(new ServletRequestContext(request));

All you need to do is remove first check. You can do this by overriding the method when creating the bean:

@Bean(name = "multipartResolver")
public CommonsMultipartResolver multipartResolver() {
    return new CommonsMultipartResolver() {
        @Override
        public boolean isMultipart(HttpServletRequest request) {
            return FileUploadBase.isMultipartContent(new ServletRequestContext(request));
        }
    };
}

PS: If you do not replace multipartResolver with your own, then the standard StandardServletMultipartResolver will work with both POST and PATCH requests