How to Build Desktop Barcode Scanner in Java and Kotlin

Dynamsoft provides Java Barcode SDKs for both mobile and desktop development. The mobile edition is distributed as an Android AAR package, and the desktop edition is distributed as a JAR package. This article aims to help developers who want to build desktop or server-side barcode scanner applications in Java or Kotlin.

Installing Dynamsoft Barcode Reader via Gradle


Create a new Gradle project:

$ gradle init
Select type of project to generate:
1: basic
2: application
3: library
4: Gradle plugin
Enter selection (default: basic) [1..4]

Select implementation language:
1: C++
2: Groovy
3: Java
4: Kotlin
5: Scala
6: Swift
Enter selection (default: Java) [1..6]

Split functionality across multiple subprojects?:
1: no - only one application project
2: yes - application and library projects
Enter selection (default: no - only one application project) [1..2]

Select build script DSL:
1: Groovy
2: Kotlin
Enter selection (default: Kotlin) [1..2]

Go to app > build.gradle to add the Maven repository hosted by Dynamsoft and the dependency:

repositories {
// Use JCenter for resolving dependencies.
maven {
url ""

dependencies {
// Use JUnit test framework.
testImplementation 'junit:junit:4.13'

// This dependency is used by the application.
implementation ''

// Dynamsoft Barcode Reader SDK
implementation 'com.dynamsoft:dbr:8.1.2'

Note: for building Android barcode scanner projects, the URL and the package name are different:

repositories {
maven {
url ""

dependencies {
implementation 'com.dynamsoft:dynamsoftbarcodereader:latest.release@aar'

Java Barcode Scanner Application for Windows, Linux, and macOS

We can open or App.kt files to instantiate the barcode reader object as follows:

// Java
import com.dynamsoft.dbr.*;

BarcodeReader br = new BarcodeReader(license);
// Kotlin
import com.dynamsoft.dbr.*

val br = BarcodeReader(license)

Click here to get a 30-day FREE Trial License if you want to unlock all API functionalities.

Dynamsoft allows developers to custom algorithms for specific scenarios. So we can visit the free barcode online demo to generate an appropriate template for parameter initialization:

// Java
br.initRuntimeSettingsWithString("{\"ImageParameter\":{\"Name\":\"Balance\",\"DeblurLevel\":5,\"ExpectedBarcodesCount\":512,\"LocalizationModes\":[{\"Mode\":\"LM_CONNECTED_BLOCKS\"},{\"Mode\":\"LM_STATISTICS\"}]}}", EnumConflictMode.CM_OVERWRITE);
// Kotlin
br.initRuntimeSettingsWithString("{\"ImageParameter\":{\"Name\":\"Balance\",\"DeblurLevel\":5,\"ExpectedBarcodesCount\":512,\"LocalizationModes\":[{\"Mode\":\"LM_CONNECTED_BLOCKS\"},{\"Mode\":\"LM_STATISTICS\"}]}}", EnumConflictMode.CM_OVERWRITE)

The following sample code is used to read barcodes from an image file and print out all results:

// Java
results = mBarcodeReader.decodeFile(file, "");
for (TextResult result : results) {
System.out.println(String.format(" Barcode %d:", index++));
if(result.barcodeFormat != 0){
System.out.println(" Type: " + result.barcodeFormatString);
} else {
System.out.println(" Type: " + result.barcodeFormatString_2);

System.out.println(" Value: " + result.barcodeText);

System.out.println(String.format(" Region points: {(%d,%d),(%d,%d),(%d,%d),(%d,%d)}",
result.localizationResult.resultPoints[0].x, result.localizationResult.resultPoints[0].y,
// Kotlin
val results: Array<TextResult> = br.decodeFile(file, "")
for (result in results) {
println(String.format(" Barcode %d:", index++))
if (result.barcodeFormat != 0) {
System.out.println(" Type: " + result.barcodeFormatString)
} else {
System.out.println(" Type: " + result.barcodeFormatString_2)
System.out.println(" Value: " + result.barcodeText)
" Region points: {(%d,%d),(%d,%d),(%d,%d),(%d,%d)}",

With a few lines of code, a simple command-line barcode scanner is done.

Here is a blurred QR code image:

We can now run the Gradle command with specified arguments.

./gradlew run --args="../../images/QR-Blurred.jpg ../../license.txt"

Testing Java Applications Using Travis CI

language: java

- name: "Linux"
os: linux
- name: "macOS"
os: osx
- name: "Windows"
os: windows
language: shell
- choco install jdk8 -params 'installdir=c:\\jdk' -y;
- export JAVA_HOME=${JAVA_HOME:-/c/jdk};
env: PATH=/c/jdk/bin:$PATH

- main

- if [[ ${TRAVIS_OS_NAME} != "windows" ]]; then
chmod +x java/gradlew;
chmod +x kotlin/gradlew;
- cd java
- ./gradlew test
- ./gradlew run --args="../../images/AllSupportedBarcodeTypes.png"
- cd ..
- cd kotlin
- ./gradlew test
- ./gradlew run --args="../../images/AllSupportedBarcodeTypes.png"

We have to add ‘ chmod +x' to make the gradlew script file work on Linux and macOS.

Source Code

Originally published at on March 8, 2021.



Manager of Dynamsoft Open Source Projects | Tech Lover

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