In this previous post, I wrote about using
System.getenv(key) to get OS environment variable. Actually,
System.getenv(key) is not new. It was introduced at the very beginning of JDK, deprecated in JDK 1.2, and reinstated in JDK 1.5 (aka JDK 5).
The reason why it was deprecated, according to JDK 1.3 javadoc:
Deprecated. The preferred way to extract system-dependent information is the system properties of the java.lang.System.getProperty methods and the corresponding getTypeName methods of the Boolean, Integer, and Long primitive types.Then bug 4199068 was submitted shortly after, requesting this method to be reinstated. Due to popular demand, this method was eventually reinstated in JDK 1.5.