pentahexed: the tale of a misleading manifest

If you have worked with Oracle's JDBC drivers before, you are no doubt familiar with ojdbc5.jar and ojdbc6.jar.

Oracle tells you that ojdbc5.jar contains Classes for use with JDK 1.5. It contains the JDBC driver classes, except classes for NLS support in Oracle Object and Collection types and that ojdbc6.jar contains Classes for use with JDK 1.6. It contains the JDBC driver classes except classes for NLS support in Oracle Object and Collection types.

Take a class oracle/core/lmx/CoreException.class from each JAR, send it to file and you are not surprised with what you see:

(for oracle/core/lmx/CoreException.class from ojdbc5.jar): compiled Java class data, version 49.0 (Java 1.5)
(for oracle/core/lmx/CoreException.class from ojdbc6.jar): compiled Java class data, version 50.0 (Java 1.6)

Open the manifest of each JAR, however, and you see something interesting. The value of Created-By is the same in both JARs: 1.5.0_30-b03 (Sun Microsystems Inc.). How can a JDK 1.5 compiler know about JDK 1.6? Surely, this has to be something lurking in the scripts that needs to be fixed. It also wouldn't hurt to use a newer version of Ant (the value of Ant-Version) is Apache Ant 1.6.5 (the latest version is 1.8.2).