Playing around with QR Codes

Sometimes QR codes are a nice way to distribute information like calendar events, contact information, e-mail, geo-locations or internet addresses. In the following article we’re going to encode information to QR code images using the ZXing library and afterwards decode information from a given QR code. Finally we’re taking a look on online QR code generators and how to integrate the ZXing library in a Maven project. The ZXing Library Download the ZXing Libraries from http://code.google.com/p/zxing/downloads/list – the file name is ZXing-<version>.zip Unpack the downloaded archive somewhere Change to the extracted directory and run ant. If you don’t have JavaME installed – and you don’t have to for the samples below – run ant buildwithoutj2me – that will do the job Having compiled the libraries you’re now free to include the core.jar from zxing-<version>/core/ and the javase.jar from zxing-<version>/javase as dependency in your project ...

May 11, 2010 · 5 min · 1041 words · Micha Kops

Snippets: Getting License Information from the Confluence API

Sometimes one needs to look up license details of a running Confluence system .. perhaps for creating a commercial plugin or to display recommendations dependant from the license used. For this reason there are a few possibilities for receiving some license information from the Confluence API or the velocity context. Note: This article is outdated since the Atlassian Marketplace was launched and a shiny new licensing API was added. Until this article is updated I strongly recommend to take a closer look at the detailed information that Atlassian is providing in the Developer Documentation. ...

May 6, 2010 · 3 min · 637 words · Micha Kops

Observability Snippets

Observability Strategies USE USE stands for: Utilization - Percent time the resource is busy, such as node CPU usage Saturation - Amount of work a resource has to do, often queue length or node load Errors - Count of error events This method is best for hardware resources in infrastructure, such as CPU, memory, and network devices. For more information, refer to The USE Method. Source: https://grafana.com/docs/grafana/latest/dashboards/build-dashboards/best-practices/ RED RED stands for: Rate - Requests per second Errors - Number of requests that are failing Duration - Amount of time these requests take, distribution of latency measurements This method is most applicable to services, especially a microservices environment. For each of your services, instrument the code to expose these metrics for each component. RED dashboards are good for alerting and SLAs. A well-designed RED dashboard is a proxy for user experience. ...

March 1, 2010 · 2 min · 231 words · Micha Kops