Category: Java

Before the introduction of Generics in Java 5 it’s commonly known that in a class you can’t have two methods with the same signature that differ by return type alone.  More formally, the Java Language Specification §8.4.2 says that “it is a compile time error to declare two methods with override-equivalent signatures in a class”.  Take Read More …

Apache POI is a full-featured Java library for reading several different Microsoft file formats, including Excel. (Note: this post only covers POI version 3.0.2-FINAL released in February 2008). POI supports evaluating cells with formulas containing Excel functions. For example, consider the code below for reading a java.util.Date from a simple spreadsheet with the formula “=NOW()” Read More …

Have you noticed that your smallest time deltas using System.currentTimeMillis() are usually 15 or 16 milliseconds on Windows?