Compiling JDBC - problem

Trying to build JDBC:
$ ant
Searching for build.xml ...
Buildfile: /usr3/home/olly/mypackages/pg7.1/postgresql-7.1beta5/build.xml

jar:

call:

prepare:
[mkdir] Created dir: /usr3/home/olly/mypackages/pg7.1/postgresql-7.1beta5/s
rc/interfaces/jdbc/build
[mkdir] Created dir: /usr3/home/olly/mypackages/pg7.1/postgresql-7.1beta5/s
rc/interfaces/jdbc/jars

check_versions:

driver:
[copy] Copying 1 files to /usr3/home/olly/mypackages/pg7.1/postgresql-7.1b
eta5/src/interfaces/jdbc/org/postgresql
Configured build for the JDBC2 edition driver.

compile:
[javac] Compiling 40 source files to /usr3/home/olly/mypackages/pg7.1/postg
resql-7.1beta5/src/interfaces/jdbc/build

BUILD FAILED

/usr3/home/olly/mypackages/pg7.1/postgresql-7.1beta5/src/interfaces/jdbc/build.
xml:99: Cannot use classic compiler, as it is not available

...bafflement! What is "classic compiler"? The XML line begins "<javac".
I have jdk1.1 installed, which contains /usr/lib/jdk1.1/bin/javac.

What else am I missing? (I am not experienced with Java.)

--
Oliver Elphick Oliver(dot)Elphick(at)lfix(dot)co(dot)uk
Isle of Wight http://www.lfix.co.uk/oliver
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