1.7 is commonly referred to as Java 7, 1.8 as Java 8 and so on.
Java 8 was released in March 2014.
You can get version with:
java -version
javac -version
Sample output:
1.8.0-ea
More verbose version:
java -fullversion
javac -fullversion
Sample output:
1.8.0-ea-b97
You can switch between multiple Java versions on a single machine with update-java-alternatives.
Java is highly binary backwards compatible, with some source breaks along the way.
- http://stackoverflow.com/questions/1654923/are-there-any-specific-examples-of-backward-incompatibilities-between-java-versi
- http://stackoverflow.com/questions/4692626/is-jdk-upward-or-backward-compatible
- http://stackoverflow.com/questions/16143684/can-java-8-code-be-compiled-to-run-on-java-7-jvm
Oracle mentions three types of compatibility:
- Source: Source compatibility concerns translating Java source code into class files including whether or not code still compiles at all.
- Binary: Binary compatibility is defined in The Java Language Specification as preserving the ability to link without error.
- Behavioral: Behavioral compatibility includes the semantics of the code that is executed at runtime.
Project that decided which proposed language extensions should or not be added to Java 7: https://blogs.oracle.com/darcy/entry/project_coin_final_five
Old name used for Java between versions 1.2 and 1.5.
The 2 was from the 1.2 which introduced major changes.