Category Archives: Java

Google App Engine, Java, JPA 2, Spring Framework, Maven

DISCLAIMER: This was going (in 2014!) to be a full tutorial but at some point I’ve lost motivation in digging in the Google App Engine. Actually I was so tired with this GAE data store that I felt really relieved … Continue reading

Posted in GoogleAppEngine, Java, Spring | Tagged , , | 1 Comment

RSA signatures in Java with Bouncy Castle

This is a complete guide, starting from RSA key pair generation into PEM files, through loading private/public keys from files into proper Bouncy Castle objects, to digital signature creation and verification – all using Bouncy Castle. No JCA. How to … Continue reading

Posted in Java, security | Tagged , | Leave a comment

Sequence of digits from natural numbers

Around a year ago I was taking a part, as a candidate, in a recruitment process in one of the world’s biggest and most innovative software companies. One question was to propose an algorithm to solve the following problem: Given … Continue reading

Posted in Java | Tagged , | Leave a comment

EasyMock vs Mockito

Just wanted to share my personal opinion on these 2 great mocking frameworks for Java. After years of experience with both of them… …I say Mockito is better. Mainly because it requires less code to do the same. I don’t … Continue reading

Posted in Java | Tagged , , , | Leave a comment

Base64 utils for Java

Last time I needed to add Base64 encoding to represent some binary data as a text. Especially I needed the functionality of translating a part (with given offset and length) of a byte array and get a result as a … Continue reading

Posted in Java | Tagged | 2 Comments

AES 256 without JCE Unlimited Strength Jurisdiction Policy Files

Once upon a time I wanted my Java application to encrypt/decrypt some data. I decided to use AES (Advanced Encryption Standard, Rijndael) encryption algorithm with 256-bit key. AES is supported by Java SE by a built-in JCA (Java Cryptography Architecture) … Continue reading

Posted in Java | Tagged , , , | Leave a comment

Turning a laptop into a Java application server in 10 steps

This is just my own proposition of a list of things needed to be done to turn a laptop into a Java application server based on Apache Tomcat under control of a Linux operating system, optionally using PostgreSQL as a … Continue reading

Posted in database, Java, Linux, Tomcat | Leave a comment