When importing some Archive projects in a workspace where a Java5 JRE exists, there is a compilation error because of the use of String#isEmpty() which is defined in Java6+

Steps to reproduce:
Import the Archives projects in a workspace where a JRE5 exists
Assert: no compilation error
Fail: compilation errors in archives/plugins/org.jboss.ide.eclipse.archives.core/src/main/org/jboss/ide/eclipse/archives/core/model/interna/xb/XMLBinding.java
because String#isEmpty() was defined in Java6

The problem does not appear if the workspace is configured with a Java6 (or more) JRE.