README.jdk5

Guava: Google Core Libraries for Java (JDK5 Backport)
=====================================================

This is the JDK5 backport of Guava. Notable differences from the
JDK6 version of Guava include:

- A variety of code is removed, most notably code that uses
  `Math.scalb`, `Deque` and its inheritors, `NavigableMap`,
  `NavigableSet` and their inheritors, and lots of methods that don't
  make sense without the above. 
- `TimeUnit` only supports `SECONDS` as the highest granularity time
  unit in 1.5, so all uses of `MINUTES`, `DAYS` and `HOURS` have been
  re-cast in terms of `SECONDS`.
- `Charset`-accepting methods on `String` and elsewhere were added in
  1.6, so all charsets are passed in by using `Charsets.FOO.name()`,
  and exceptions are trapped or thrown as appropriate. 
- The guava-gwt module is disabled by not including it in the list
  of modules in the parent pom.xml.

The JDK5 backport builds with Maven, but has a number of
ideosyncrasies.

- While it uses `-source 1.5` and `-target 1.5` and produces valid 1.5
  compatible class files, the backport does not build with JDK5.
  @Override annotations on interface methods are retained.
- It requries a custom ExecutorService and AbstractExecutorService,
  which we build in a boostrap project which is included in the build
  of guava, guava-testlib and guava-tests.
- The Maven build will use a bootstrap rt.jar classpath based on a
  standard sun JDK on unix. But this is overridable on a Mac by
  passing in `-Dbootstrap.classes=/path/to/my/classes.jar`. Since
  the backport will not build with JDK5, a JDK5 `rt.jar` should be used
  to ensure that no JDK6+ APIs are used. If you have difficulties
  building, please try setting the `bootstrap.classes` property to a
  known `rt.jar` or `classes.jar`.
- Some tests will fail when run under JDK5 due to `guava-testlib` and
  `guava-tests` having dependencies on other libraries that are compiled
  with `-target 1.6`.