diff --git a/.env b/.env
new file mode 100644
index 0000000..c1f2316
--- /dev/null
+++ b/.env
@@ -0,0 +1,5 @@
+MONGODB_PORT=27017
+APP_PORT=8990
+OCR_TESSERACT_DATA-PATH=/usr/local/share/tessdata/
+
+TESSERACT_VERSION=5.4.1
\ No newline at end of file
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 0000000..ccdfdfb
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,29 @@
+name: CI
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout source
+        uses: actions/checkout@v4
+
+      - name: Set up JDK 21
+        uses: actions/setup-java@v4
+        with:
+          java-version: '21'
+          distribution: 'temurin'
+
+      - name: Make gradlew executable
+        run: chmod +x ./gradlew
+
+      - name: Run build with Gradle Wrapper
+        run: ./gradlew build
\ No newline at end of file
diff --git a/.tesseract/get-languages.sh b/.tesseract/get-languages.sh
new file mode 100644
index 0000000..184e6f5
--- /dev/null
+++ b/.tesseract/get-languages.sh
@@ -0,0 +1,8 @@
+#!/bin/bash
+readarray -t languages < <(sed 's/\r$//' languages.txt)
+for i in "${languages[@]}"
+do
+  echo "Downloading ${i}.traineddata"
+  wget -qO ${i}.traineddata https://github.com/tesseract-ocr/tessdata_best/blob/main/${i}.traineddata?raw=true
+done
+echo "Done"
\ No newline at end of file
diff --git a/.tesseract/get-scripts.sh b/.tesseract/get-scripts.sh
new file mode 100644
index 0000000..0fc627c
--- /dev/null
+++ b/.tesseract/get-scripts.sh
@@ -0,0 +1,8 @@
+#!/bin/bash
+readarray -t scripts < <(sed 's/\r$//' scripts.txt)
+for i in "${scripts[@]}"
+do
+  echo "Downloading ${i}.traineddata"
+  wget -qO ${i}.traineddata https://github.com/tesseract-ocr/tessdata_best/blob/main/script/${i}.traineddata?raw=true
+done
+echo "Done"
\ No newline at end of file
diff --git a/.tesseract/languages.txt b/.tesseract/languages.txt
new file mode 100644
index 0000000..c74ba6a
--- /dev/null
+++ b/.tesseract/languages.txt
@@ -0,0 +1,8 @@
+hrv
+eng
+deu
+ita
+fra
+lat
+ell
+osd
\ No newline at end of file
diff --git a/.tesseract/scripts.txt b/.tesseract/scripts.txt
new file mode 100644
index 0000000..f50862b
--- /dev/null
+++ b/.tesseract/scripts.txt
@@ -0,0 +1,6 @@
+Cyrillic
+Fraktur
+Greek
+Latin
+Hebrew
+Arabic
\ No newline at end of file
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..a6dd8b5
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,78 @@
+FROM eclipse-temurin:21-jdk AS app_stage
+
+WORKDIR /app
+
+COPY build.gradle.kts .
+COPY settings.gradle.kts .
+COPY gradlew .
+COPY gradle/ ./gradle
+
+RUN ./gradlew clean
+
+COPY src/ ./src/
+
+RUN ./gradlew clean bootJar
+
+
+FROM ubuntu:22.04 AS tesseract
+
+LABEL authors="nenadjakic"
+
+ARG DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get -y update
+RUN apt-get -y install \
+    automake \
+    ca-certificates \
+    g++ \
+    git \
+    libtool \
+    libleptonica-dev \
+    make \
+    pkg-config
+
+RUN apt-get -y install --no-install-recommends \
+    asciidoc \
+    docbook-xsl \
+    xsltproc
+
+WORKDIR /src
+
+ARG TESSERACT_VERSION
+
+RUN git clone -b $TESSERACT_VERSION https://github.com/tesseract-ocr/tesseract.git
+
+WORKDIR /src/tesseract
+
+RUN ./autogen.sh
+RUN ./configure
+RUN make
+RUN make install
+RUN ldconfig
+
+RUN apt-get -y install \
+    wget
+
+WORKDIR /usr/local/share/tessdata/
+
+COPY .tesseract/get-languages.sh .
+COPY .tesseract/languages.txt .
+
+RUN chmod +x ./get-languages.sh
+RUN ./get-languages.sh
+
+WORKDIR /usr/local/share/tessdata/scripts
+
+COPY .tesseract/get-scripts.sh .
+COPY .tesseract/scripts.txt .
+
+RUN chmod +x ./get-scripts.sh
+RUN ./get-scripts.sh
+
+RUN apt-get -y install openjdk-21-jdk
+
+WORKDIR /app
+
+COPY --from=app_stage /app/build/libs/ocr-studio.jar .
+
+CMD ["java", "-jar", "ocr-studio.jar"]
diff --git a/README.md b/README.md
index ee476ef..afd6b9e 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,33 @@
 # ocr-studio
 **Development in progress**
+
+## Table of Contents
+- [Description](#description)
+- [Features](#features)
+- [Technologies used](#technologies-used)
+- [Getting started](#getting-started)
+  - [Requirements](#requirements)
+  - [Build and run](#build-and-run)
+  - [Dockerize Application](#dockerize-application)
+    - [Installing Docker and Docker Compose](#installing-docker-and-docker-compose)
+    - [Running Application with Docker Compose](#running-application-with-docker-compose)
+- [Configuration](#configuration)
+  - [MongoDB Configuration](#mongodb-configuration)
+  - [File Upload Configuration](#file-upload-configuration)
+  - [OCR Configuration](#ocr-configuration)
+- [Usage](#usage)
+  - [Important REST methods](#important-rest-methods)
+    - [Task controller](#task-controller)
+    - [Ocr controller](#ocr-controller)
+  - [Use cases](#use-cases)
+  - [Licence](#license)
+
 ## Description
+
 This application is designed for managing OCR (Optical Character Recognition) tasks. It allows users to define, schedule, and execute OCR tasks through a REST API. The core technologies used are Spring Framework, MongoDB, and Tesseract OCR.
 
 ## Features
+
 - **Task Definition**: Users can create OCR tasks by specifying parameters such as the language, scheduling time, and other options.
 - **Document Upload**: Upload the documents that need to be processed as part of the OCR task.
 - **Task Scheduling**: Once the task is fully defined, it can be scheduled to run at a specified time.
@@ -12,45 +36,175 @@ This application is designed for managing OCR (Optical Character Recognition) ta
     - **Tasks**: All task definitions and metadata are stored in a MongoDB database.
     - **Documents**: Uploaded documents are stored on the file system.
 
-## Technologies Used
+## Technologies used
 
 - **Spring Framework**: The backbone of the application, used for dependency injection, REST API creation, and overall application management.
 - **MongoDB**: A NoSQL database used to store task definitions and execution logs.
 - **Tesseract OCR**: An open-source OCR engine used for processing the uploaded documents according to the defined task parameters.
 
-## How to Use
-
-1. **Define a Task**: Use the REST API to define an OCR task. Parameters include language, execution time, and Tesseract options.
-2. **Upload Documents**: Attach the documents that need to be processed by the OCR task. The documents will be saved to the file system.
-3. **Schedule the Task**: Once all necessary details are provided, schedule the task to run at the desired time.
-4. **Execution**: The application will execute the task at the scheduled time, processing the documents with the specified Tesseract options.
-
 ## Getting Started
 
-To run this application locally:
-
-1. Clone the repository.
-``` bash 
-git clone https://github.com/nenadjakic/ocr-studio.git
-cd ocr-studio
-```
-2. Configure the MongoDB connection and file storage paths in the `application.properties` file.
-3. Build the project using Gradle.
-```bash 
-.\gradlew clean bootJar
-```
-4. Run the application.  
-``` bash 
-.\gradlew bootRun 
-```
-
-## Requirements
-
+### Requirements
 - **Java 21** or higher
 - **Gradle** for dependency management
 - **MongoDB** instance
 - **Tesseract OCR** installed and configured
 - **File System** with sufficient storage for document processing
 
+### Build and run
+
+To run this application locally:
+
+1. Clone the repository.
+
+``` git clone https://github.com/nenadjakic/ocr-studio.git ```
+
+2. Navigate to the project directory:
+
+``` cd ocr-studio ```
+
+3. Configure the MongoDB connection and file storage paths in the `application.properties` file.
+4. Build the project using Gradle.
+
+``` .\gradlew clean bootJar ```
+
+5. Run the application.  
+
+```  .\gradlew bootRun ```
+
+### Dockerize Application
+
+Follow these steps to dockerize and run your application using Docker and Docker Compose:
+
+#### Installing Docker and Docker Compose
+
+Before dockerizing your application, ensure that Docker and Docker Compose are installed on your machine. If not already installed, you can follow these guides:
+
+- [Docker Install Guide](https://docs.docker.com/get-docker/)
+- [Docker Compose Install Guide](https://docs.docker.com/compose/install/)
+
+#### Running Application with Docker Compose
+
+Once Docker and Docker Compose are installed, you can use Docker Compose to build and run your application in a container:
+
+``` docker compose up ```
+
+## Configuration
+
+The application can be configured using the following properties, which can be set in the `application.properties` file. These properties allow you to customize the behavior of the application, including database connections, file upload limits, logging levels, and OCR paths.
+
+### MongoDB Configuration
+
+- **`spring.data.mongodb.uri`**: The URI for connecting to the MongoDB database.  
+  **Example:** `mongodb://localhost:2010/ocr-studio`
+
+- **`spring.data.mongodb.uuid-representation`**: Defines how UUIDs should be represented in MongoDB. The `standard` value ensures compatibility with most systems.  
+  **Default:** `standard`
+
+### File Upload Configuration
+
+- **`spring.servlet.multipart.max-file-size`**: Specifies the maximum file size for uploads.  
+  **Default:** `1024MB`
+
+- **`spring.servlet.multipart.max-request-size`**: Specifies the maximum request size, including the file size and any other request data.  
+  **Default:** `1024MB`
+
+### OCR Configuration
+
+- **`ocr.task-path`**: Specifies the path where OCR tasks are stored or accessed. This path should be configured according to your file storage setup. If not specified tasks directories will be created in working app directory.   
+  **Default:**  
+
+- **`ocr.tesseract.data-path`**: Path to the Tesseract OCR data files, which include language models and other resources. Ensure that this path is correctly set to avoid errors during OCR processing.  
+  **Example:** `\\\\wsl.localhost\\Ubuntu-22.04\\usr\\share\\tesseract-ocr\\4.00\\tessdata`
+
+## Usage
+
+This application is designed to manage OCR (Optical Character Recognition) tasks efficiently. It provides a REST API for defining, scheduling, and executing OCR tasks. Below is a guide on how to use the key features of the application.
+
+### Important REST methods
+
+#### Task controller
+>  **Retrieve All Tasks**
+> 
+> To get a list of all the tasks you have, use the following endpoint:
+> 
+> **Endpoint**  
+> `GET /task`
+> 
+> **Description**  
+> Retrieves all tasks from the system.
+
+> **Create a New Task**
+> 
+> To add a new task, use the following endpoint. You can provide details about the task and upload any necessary files.
+> 
+> **Endpoint**  
+> `POST /task`
+> 
+> **Description**  
+> Creates a new task based on the provided model. The request should include details of the task and any files you want to upload.
+> Application will save task to database, create task's directories. Main directory will be named as task id. Parent of main direcotry will be specifed with property `ocr.task-path`
+> 
+> ***Created directory tree:***
+> - `task_id`
+>   - `input`
+>   - `output`
+>
+> If files are provided, they will be stored into directory `task_id/input/`
+
+> **Create a Draft Task**
+>
+> To create a draft of a task, use the following endpoint. This is useful for setting up tasks that are not yet finalized.
+>
+> **Endpoint**  
+> `POST /task/draft`
+>
+> **Description**  
+> Creates a new draft task based on the provided model. This draft can be reviewed and updated before finalizing.
+>
+> ***See `POST/task` for created directories.***
+
+> **Upload Files to a Task**
+>
+> **Endpoint**  
+> `PUT /task/upload/{id}`
+>
+> **Description**  
+> Uploads files for the specified task, defined with `{id}`. This endpoint helps in attaching files.
+
+### Ocr controller
+
+> **Get OCR Job Progress**
+> 
+> **Endpoint**  
+> `GET /ocr`
+> 
+> **Description**  
+> Retrieves the progress of an OCR job for the specified ID. This endpoint allows you to monitor how far along the OCR process is.
+> If task is not scheduled yet, application will return progress information from database.
+
+> **Interrupt OCR Job**
+> 
+> **Endpoint**  
+> `PUT /ocr`
+> 
+> **Description**  
+> Interrupts the OCR job for the specified task id. Use this endpoint to stop an ongoing OCR process.
+
+> ##### Schedule OCR Job
+> 
+> **Endpoint**  
+> `POST /ocr`
+> 
+> **Description**  
+> Schedules an OCR job for the specified task. If the task has a defined start time, the OCR job will begin as soon as possible after that time and when an executor is available. If no start time is defined, the job will be initiated as soon as possible depending on the availability of an executor.
+> If task is already scheduled, or if it has wrong status, application will throw error.
+
+## Use cases
+- **User wants to OCR one image with some english text and as output wants pdf document. User wants to do OCR immediately.**
+- **User wants to OCR multiple images. User wants to do OCR immediately.**
+- **User wants to OCR multipage pdf document, and as output wants pdf document. User wants to start execution at specified time.**
+  
+
 ## License
 This project is licensed under the Apache License - see the LICENSE file for details.
\ No newline at end of file
diff --git a/build.gradle.kts b/build.gradle.kts
index bd9103d..57f913a 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -45,6 +45,10 @@ tasks.withType<KotlinCompile> {
     }
 }
 
+tasks.bootJar {
+    archiveFileName.set("${archiveBaseName.get()}.${archiveExtension.get()}")
+}
+
 tasks.test {
     useJUnitPlatform()
 }
diff --git a/docker-compose.yaml b/docker-compose.yaml
new file mode 100644
index 0000000..b6f0844
--- /dev/null
+++ b/docker-compose.yaml
@@ -0,0 +1,39 @@
+services:
+  mongodb:
+    image: mongo:7.0.12-jammy
+    container_name: ocr-studio-mongodb
+    restart: unless-stopped
+    ports:
+      - "${MONGODB_PORT}:27017"
+    networks:
+      - ocr-studio-network
+    volumes:
+      - ocr-studio-mongo-data:/data/db
+  ocr-studio:
+    build:
+      context: .
+      dockerfile: Dockerfile
+      args:
+        TESSERACT_VERSION: ${TESSERACT_VERSION}
+    ports:
+      - "${APP_PORT}:8080"
+    container_name: ocr-studio-app
+    depends_on:
+      - mongodb
+    environment:
+      OCR_TASK-PATH: /opt/data/tasks
+      OCR_TESSERACT_DATA-PATH: ${OCR_TESSERACT_DATA-PATH}
+      SPRING_DATA_MONGODB_URI: mongodb://ocr-studio-mongodb:27017/ocr-studio
+    networks:
+      - ocr-studio-network
+    volumes:
+      - type: volume
+        source: ocr-studio-task-data
+        target: /opt/data/tasks
+networks:
+  ocr-studio-network:
+volumes:
+  ocr-studio-mongo-data:
+    name: ocr-studio-mongo-data
+  ocr-studio-task-data:
+    name: ocr-studio-task-data
\ No newline at end of file
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..d64cd49
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/src/main/kotlin/com/github/nenadjakic/ocr/studio/controller/OcrConfigController.kt b/src/main/kotlin/com/github/nenadjakic/ocr/studio/controller/OcrConfigController.kt
index 336e522..0b480d6 100644
--- a/src/main/kotlin/com/github/nenadjakic/ocr/studio/controller/OcrConfigController.kt
+++ b/src/main/kotlin/com/github/nenadjakic/ocr/studio/controller/OcrConfigController.kt
@@ -1,5 +1,6 @@
 package com.github.nenadjakic.ocr.studio.controller
 
+import com.github.nenadjakic.ocr.studio.dto.FileFormatResponse
 import com.github.nenadjakic.ocr.studio.dto.OcrEngineModeResponse
 import com.github.nenadjakic.ocr.studio.dto.PageSegmentationModeResponse
 import com.github.nenadjakic.ocr.studio.entity.OcrConfig
@@ -23,7 +24,7 @@ class OcrConfigController {
         description = "Returns a collection with ocr engine modes.")
     @ApiResponses(
         value = [
-            ApiResponse(responseCode = "200", description = "Successfully retrieved page of tasks.")
+            ApiResponse(responseCode = "200", description = "Successfully retrieved page of ocr engine modes.")
         ]
     )
     @GetMapping("/engine-mode")
@@ -36,10 +37,23 @@ class OcrConfigController {
         description = "Returns a collection with page segmentation modes.")
     @ApiResponses(
         value = [
-            ApiResponse(responseCode = "200", description = "Successfully retrieved page of tasks.")
+            ApiResponse(responseCode = "200", description = "Successfully retrieved page segmentation modes.")
         ]
     )
     @GetMapping("/page-segmentation-mode")
     fun findOcrPageSegmentationModes(): ResponseEntity<Collection<PageSegmentationModeResponse>> =
         ResponseEntity.ok(OcrConfig.PageSegmentationMode.entries.map { PageSegmentationModeResponse(it.name, it.descritpion) })
+
+    @Operation(
+        operationId = "findFileFormats",
+        summary = "Get all file formats.",
+        description = "Returns a collection with file formats.")
+    @ApiResponses(
+        value = [
+            ApiResponse(responseCode = "200", description = "Successfully retrieved of file formats.")
+        ]
+    )
+    @GetMapping("/file-format")
+    fun findOcrFileFormats(): ResponseEntity<Collection<FileFormatResponse>> =
+        ResponseEntity.ok(OcrConfig.FileFormat.entries.map { FileFormatResponse(it.name, it.getExtension(), it.toRenderedFormat().name) })
 }
\ No newline at end of file
diff --git a/src/main/kotlin/com/github/nenadjakic/ocr/studio/controller/TaskController.kt b/src/main/kotlin/com/github/nenadjakic/ocr/studio/controller/TaskController.kt
index 9f4b3ba..59019b3 100644
--- a/src/main/kotlin/com/github/nenadjakic/ocr/studio/controller/TaskController.kt
+++ b/src/main/kotlin/com/github/nenadjakic/ocr/studio/controller/TaskController.kt
@@ -93,7 +93,7 @@ open class TaskController(
         model: TaskAddRequest,
         @RequestPart(value = "files", required = false) files: Collection<MultipartFile>?
     ): ResponseEntity<Void> {
-        var task = modelMapper.map(model, Task::class.java)
+        val task = modelMapper.map(model, Task::class.java)
         return insert(task, files)
     }
 
@@ -110,7 +110,7 @@ open class TaskController(
     )
     @PostMapping(value = ["/draft"], consumes = [MediaType.APPLICATION_JSON_VALUE])
     fun create(@Valid @RequestBody model: TaskDraftRequest): ResponseEntity<Void> {
-        var task = modelMapper.map(model, Task::class.java)
+        val task = modelMapper.map(model, Task::class.java)
         return insert(task)
     }
 
diff --git a/src/main/kotlin/com/github/nenadjakic/ocr/studio/dto/FileFormatResponse.kt b/src/main/kotlin/com/github/nenadjakic/ocr/studio/dto/FileFormatResponse.kt
new file mode 100644
index 0000000..9a0535d
--- /dev/null
+++ b/src/main/kotlin/com/github/nenadjakic/ocr/studio/dto/FileFormatResponse.kt
@@ -0,0 +1,7 @@
+package com.github.nenadjakic.ocr.studio.dto
+
+data class FileFormatResponse(
+    val value: String,
+    val extension: String,
+    val tesseractFormat: String
+)
diff --git a/src/main/kotlin/com/github/nenadjakic/ocr/studio/entity/DocumentConfig.kt b/src/main/kotlin/com/github/nenadjakic/ocr/studio/entity/DocumentConfig.kt
deleted file mode 100644
index 746838e..0000000
--- a/src/main/kotlin/com/github/nenadjakic/ocr/studio/entity/DocumentConfig.kt
+++ /dev/null
@@ -1,5 +0,0 @@
-package com.github.nenadjakic.ocr.studio.entity
-
-class DocumentConfig {
-    lateinit var fileName: String
-}
\ No newline at end of file
diff --git a/src/main/kotlin/com/github/nenadjakic/ocr/studio/executor/OcrExecutor.kt b/src/main/kotlin/com/github/nenadjakic/ocr/studio/executor/OcrExecutor.kt
index 60efba7..1c1bd7f 100644
--- a/src/main/kotlin/com/github/nenadjakic/ocr/studio/executor/OcrExecutor.kt
+++ b/src/main/kotlin/com/github/nenadjakic/ocr/studio/executor/OcrExecutor.kt
@@ -12,7 +12,6 @@ import org.apache.pdfbox.Loader
 import org.apache.pdfbox.pdmodel.PDDocument
 import org.apache.pdfbox.rendering.ImageType
 import org.apache.pdfbox.rendering.PDFRenderer
-import org.apache.tika.metadata.PDF
 import org.slf4j.LoggerFactory
 import java.io.File
 import java.io.IOException
@@ -20,7 +19,6 @@ import java.nio.file.Path
 import java.time.ZonedDateTime
 import java.util.*
 import javax.imageio.ImageIO
-import kotlin.collections.Map
 
 class OcrExecutor(
     override val id: UUID,
@@ -95,6 +93,9 @@ class OcrExecutor(
                 }
                 task.ocrProgress = progressInfo.toOcrProgress()
                 taskRepository.save(task)
+            }
+            if (task.ocrConfig.mergeDocuments) {
+
             }
             progressInfo.progressInfoStatus = ProgressInfo.ProgressInfoStatus.FINISHED
             task.ocrProgress = progressInfo.toOcrProgress()
@@ -125,7 +126,7 @@ class OcrExecutor(
                 if (result) {
                     files[order++] = tempGrayscaleImage
                 }
-            } else if (mediaType.toString().equals("application/pdf")) {
+            } else if (mediaType.toString() == "application/pdf") {
                Loader.loadPDF(inFile).use  {
                     val pdfRenderer = PDFRenderer(it)
                     logger.info("Starting of pdf preprocess. Total pages: ${it.numberOfPages}")
diff --git a/src/main/kotlin/com/github/nenadjakic/ocr/studio/executor/ParallelizationManagerImpl.kt b/src/main/kotlin/com/github/nenadjakic/ocr/studio/executor/ParallelizationManagerImpl.kt
index e75e974..006e07e 100644
--- a/src/main/kotlin/com/github/nenadjakic/ocr/studio/executor/ParallelizationManagerImpl.kt
+++ b/src/main/kotlin/com/github/nenadjakic/ocr/studio/executor/ParallelizationManagerImpl.kt
@@ -36,7 +36,7 @@ class ParallelizationManagerImpl(
         val resultMap = mutableMapOf<UUID, Boolean?>()
 
         for (futureEntry in futures.entries) {
-            resultMap.put(futureEntry.key, futureEntry.value.cancel(true))
+            resultMap[futureEntry.key] = futureEntry.value.cancel(true)
         }
 
         return resultMap
diff --git a/src/main/kotlin/com/github/nenadjakic/ocr/studio/executor/ProgressInfo.kt b/src/main/kotlin/com/github/nenadjakic/ocr/studio/executor/ProgressInfo.kt
index 5a59b5b..9ccef63 100644
--- a/src/main/kotlin/com/github/nenadjakic/ocr/studio/executor/ProgressInfo.kt
+++ b/src/main/kotlin/com/github/nenadjakic/ocr/studio/executor/ProgressInfo.kt
@@ -1,7 +1,5 @@
 package com.github.nenadjakic.ocr.studio.executor
 
-import com.github.nenadjakic.ocr.studio.entity.OcrProgress
-
 data class ProgressInfo(
     var taskDone: Int,
     var totalTasks: Int,
diff --git a/src/main/kotlin/com/github/nenadjakic/ocr/studio/extension/MultipartFileExtension.kt b/src/main/kotlin/com/github/nenadjakic/ocr/studio/extension/MultipartFileExtension.kt
index bcaf380..033a7e1 100644
--- a/src/main/kotlin/com/github/nenadjakic/ocr/studio/extension/MultipartFileExtension.kt
+++ b/src/main/kotlin/com/github/nenadjakic/ocr/studio/extension/MultipartFileExtension.kt
@@ -1,9 +1,3 @@
 package com.github.nenadjakic.ocr.studio.extension
 
-import org.springframework.web.multipart.MultipartFile
-import java.io.File
 
-
-fun MultipartFile.toFile(targetFile: File) {
-    this.transferTo(targetFile)
-}
\ No newline at end of file
diff --git a/src/main/kotlin/com/github/nenadjakic/ocr/studio/service/TaskFileSystemService.kt b/src/main/kotlin/com/github/nenadjakic/ocr/studio/service/TaskFileSystemService.kt
index 19fe182..8ffff6e 100644
--- a/src/main/kotlin/com/github/nenadjakic/ocr/studio/service/TaskFileSystemService.kt
+++ b/src/main/kotlin/com/github/nenadjakic/ocr/studio/service/TaskFileSystemService.kt
@@ -30,7 +30,7 @@ class TaskFileSystemService(
 
         fun getContentType(file: File): MediaType = detector.detect(cloneInputStream(file.inputStream()), Metadata())
 
-        fun getContentType(multiPartFile: MultipartFile): String {
+        fun getContentType(multiPartFile: MultipartFile): String? {
             var contentType = multiPartFile.contentType
 
             if ("application/octet-stream".equals(contentType, true)) {
diff --git a/src/main/kotlin/com/github/nenadjakic/ocr/studio/service/TaskService.kt b/src/main/kotlin/com/github/nenadjakic/ocr/studio/service/TaskService.kt
index 9fa2536..3d0ab01 100644
--- a/src/main/kotlin/com/github/nenadjakic/ocr/studio/service/TaskService.kt
+++ b/src/main/kotlin/com/github/nenadjakic/ocr/studio/service/TaskService.kt
@@ -37,10 +37,10 @@ class TaskService(
 
     fun insert(entity: Task, files: Collection<MultipartFile>? = emptyList()): Task {
         val createdEntity = insert(entity)
-        if (files != null && !files!!.isEmpty()) {
+        if (files != null && !files.isEmpty()) {
             upload(createdEntity.id!!, files)
         }
-        return createdEntity;
+        return createdEntity
     }
 
     fun update(entity: Task): Task = taskRepository.save(entity)