Thanks to Colin Lamond for this tip:
When using J2SE 1.4 with the Sun Web Service Development Kit (WSDK) 1.6 with iBATIS, you get a java.lang.NoSuchMethodError when you call SqlMapClientBuilder.buildSqlMapClient(reader) to create the sql map.
The Sun WSDK 1.6 is shipped with JAXP 1.3, but J2SE 1.4 includes JAXP1.1, and the two versions are not compatible because they come from completely different code bases.
To resolve this issue you have to make the JVM ignore the shipped 1.1 version and use 1.3 by using the endorsed option to override 1.1 with 1.3, e.g.
java -Djava.endorsed.dirs=C:\jaxp\lib;C:\jaxp\lib\endorsed -cp C:\build TestClass