I found a failure in a JDBC driver of 7.2b4.
(1) It does not support timestamptz type
(2) Exception occurs by timestamp without time zone type
I attach a patch correcting the first failure.
You can confirm it in example.psql as follows:
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$ java -cp postgresql-examples.jar:postgresql.jar example.psql jdbc:postgresql:r-matuda r-matuda pass
PostgreSQL psql example v6.3 rev 1
Connecting to Database URL = jdbc:postgresql:r-matuda
Connected to PostgreSQL 7.2b4
[1] select 'now'::timestamp;
timestamptz
No class found for timestamptz.
[1] [1] select 'now'::timestamp with time zone;
timestamptz
No class found for timestamptz.
[1] [1] select 'now'::timestamp without time zone;
timestamp
Exception caught.
java.lang.StringIndexOutOfBoundsException: String index out of range: 26
java.lang.StringIndexOutOfBoundsException: String index out of range: 26
at java.lang.String.charAt(String.java:516)
at org.postgresql.jdbc2.ResultSet.toTimestamp(ResultSet.java:1653)
at org.postgresql.jdbc2.ResultSet.getTimestamp(ResultSet.java:398)
at org.postgresql.jdbc2.ResultSet.getObject(ResultSet.java:768)
at example.psql.displayResult(psql.java:137)
at example.psql.processLine(psql.java:96)
at example.psql.<init>(psql.java:62)
at example.psql.main(psql.java:227)