Author Archives: Christer

PGP and Yubikey

I was trying to implement client side encryption of files backed up to AWS S3 using Duplicity, with keys on my Yubikey Neo created on an air gapped installation. It worked with local PGP keys, but I didn’t get it … Continue reading

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StackOverflowException in java.util.ArrayList due to subList()

We have experienced a problem with a StackOverflowException when calling ArrayList.add(). The application added data to the end of a list to find different possible solutions. Attempts that lead to a dead end are then truncated from the list with … Continue reading

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Ubuntu 12.04 LTS och HWE

Ubuntu 12.04 LTS got something called the Hardware Enablement Stacks (HWE), to support newer hardware. A LTS release is supported for 5 years. There are different versions of the HWE, where only some is supported for the full LTS lifetime. … Continue reading

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Nvidia driver on Ubuntu 13.10

I made the mistake to try to switch from the Nvidia driver to use the hybrid Bumblebee driver on Ubuntu 13.10 for my Lenovo T420s laptop with NVIDIA GPU NVS 4200M (GF119). I ended up with a situation where I … Continue reading

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Check Java version in class files

Java classes can be compiled for different target platforms. You could e.g. compile with JDK 7 creating class files for Java 6. The target version is encoded in the beginning of the class files. The major version of the different … Continue reading

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Java encoding of source files

I got a problem with some java source files, which javac couldn’t compile, because the file encoding was correct. The source files did include some Swedish UTF-8 characters. unmappable character for encoding ASCII So I checked what my ant environment … Continue reading

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