Important JDK 1.4 information

Incompatibilities Between Java 2 Platform, Standard Edition, v1.4.0 and v1.3

The new JDK 1.4.0 compiler, as a result of stricter enforcement of Java Language Specification, requires all the imported classes should be within named namespaces(packages).  An attempt to import classes from unnamed namespace causes a compile-time error in a JDK 1.4
environment.  Also see http://java.sun.com/j2se/1.4/compatibility.html#incompatibilities1.4 point # 8 - second bullet.
This behavior of the JDK 1.4 compiler could impact applications built using JDK 1.3.1 that do not have classes within named namespaces( a not so uncommon practice especially for people writing JSPs). You will get a compile-time error.

Please ensure that you have all your imported classes within packages before moving to 10g as Oracle Application Server 10g (9.0.4) bundles JDK 1.4.

OC4J users who do not have all their imported classes within packages and still wish to use OC4J 10g (9.0.4), please continue to use JDK 1.3.1.  The OC4J 10g supports both JDK 1.3.1.x and JDK 1.4.x.  Please refer to the documentation for the exact versions of the supported JDK.