Official Klarna REST Java SDK

Getting started

SDK covers all of Klarna API: https://developers.klarna.com/api/

Prerequisites

Java 1.7 version or higher
API credentials

API Credentials

Before getting a production account you can get a playground one. Register here to be able to test your SDK integration before go live:

https://playground.eu.portal.klarna.com/developer-sign-up - for EU countries
https://playground.us.portal.klarna.com/developer-sign-up - for the US

Installing the Java SDK

The Java SDK requires Java 1.7 version or higher.

Maven

To install the Java SDK from the Central Maven repository using Maven, add the following lines to pom.xml:

<dependency>
    <groupId>com.klarna</groupId>
    <artifactId>kco-rest</artifactId>
    <version>[3.1,)</version>
</dependency>

Gradle

To install the Java SDK from the Central Maven repository using Gradle, add the following lines to build.gradle:

dependencies {
    compile group: 'com.klarna', name: 'kco-rest', version:'3.1+'
}

Documentation

The various documentation is available:

Usage

Example files can be found in the examples package.

The basic workflow is the following:

Create an SDK Client

Build the new API instance via created Client

package com.mycompany.app;

import com.klarna.rest.Client;
import com.klarna.rest.api.checkout.CheckoutOrdersApi;
import com.klarna.rest.api.checkout.model.CheckoutOrder;
import com.klarna.rest.http_transport.HttpTransport;
import com.klarna.rest.model.ApiException;

import java.io.IOException;

/**
 * Klarna Checkout Example
 */
public class App
{
    public static void main( String[] args )
    {
        Client client = new Client("username", "password", HttpTransport.EU_BASE_URL);
        CheckoutOrdersApi checkoutOrdersApi = client.newCheckoutOrdersApi();

        try {
            CheckoutOrder order = checkoutOrdersApi.fetch("checkoutOrderID-123");

            // Order has been successfully fetched, we can get some info, e.g. HTML Snippet
            // This snippet can be embedded into your website/templates/etc
            String htmlSnippet = order.getHtmlSnippet();
            System.out.println(htmlSnippet);

            // Or print a whole order data
            System.out.println(order);

        } catch (IOException e) {
            System.out.println("Connection problem: " + e.getMessage());
        } catch (ApiException e) {
            System.out.println("API issue: " + e.getMessage());
        }
    }
}

Logging and Debugging

The Java SDK uses the slf4j library as an abstraction for various logging frameworks. We have not provided any back-end implementation. Choose an implementation that applies to your project.

For more information, see the slf4j documentation.

You can debug and check all the requests and responses made via the SDK. In order to enable debug mode you need to change the logging level of your Logger to "debug".

For example, if you use log4j2 logger, put this line to your log4j2.properties file:

rootLogger.level = debug

The output will look like:

[18-Oct-25 14:16:09:652] [DEBUG] [HttpUrlConnectionTransport:312] - DEBUG MODE: Request
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
GET: https://api.playground.klarna.com/customer-token/v1/tokens/TOKEN
Headers: Headers: {User-Agent=[Language/Java_1.8.0_161 (Vendor/Oracle Corporation; VM/Java HotSpot(TM) 64-Bit Server VM) Library/Klarna.kco_rest_java_3.0.0 OS/Mac OS X_10.13.4], Content-Type=[application/json]}
Payout:

DEBUG MODE: Response
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Headers: {null=[HTTP/1.1 200 OK], Server=[openresty], Connection=[keep-alive], Vary=[Accept-Encoding], Content-Length=[166], Date=[Thu, 25 Oct 2018 12:16:09 GMT], Content-Type=[application\/json]}
Payout: {"status" : "ACTIVE","payment_method_type" : "INVOICE"}

How to contribute

At Klarna, we strive toward achieving the highest possible quality for our products. Therefore, we require you to follow these guidelines if you wish to contribute.

To contribute, the following criteria needs to be fulfilled:

Description regarding what has been changed and why
Pull requests should implement a boxed change
All code and documentation must follow the style specified by the included configuration (src/checkstyle.xml)
New features and bug fixes must have accompanying unit tests:
- Positive tests
- Negative tests
- Boundary tests (if possible)
- No less than 90% decision coverage
All unit tests should pass

Questions and feedback

If you have any questions concerning this product or the implementation, please create an issue: https://github.com/klarna/kco_rest_java/issues/new/choose

Use an official Klarna Contact us form (https://klarna.com) if you have a question about the integration.

License

The Klarna Checkout REST Java SDK is released under Apache License, Version 2.0

igeligel / kco_rest_java