I suggest to add catalog column to
java.sql.DatabaseMetaData.getSchemas()
in order to better support SQL3.
In SQL3 model (fcd2 May 1998) (look at schemata
base table in foundation p 797)

CREATE TABLE SCHEMATA
(
CATALOG_NAME INFORMATION_SCHEMA.SQL_IDENTIFIER,
SCHEMA_NAME INFORMATION_SCHEMA.SQL_IDENTIFIER,
SCHEMA_OWNER INFORMATION_SCHEMA.SQL_IDENTIFIER
CONSTRAINT SCHEMA_OWNER_NOT_NULL NOT NULL,
DEFAULT_CHARACTER_SET_CATALOG INFORMATION_SCHEMA.SQL_IDENTIFIER,
CONSTRAINT DEFAULT_CHARACTER_SET_CATALOG_NOT_NULL NOT NULL,
DEFAULT_CHARACTER_SET_SCHEMA INFORMATION_SCHEMA.SQL_IDENTIFIER,
CONSTRAINT DEFAULT_CHARACTER_SET_SCHEMA_NOT_NULL NOT NULL,
DEFAULT_CHARACTER_SET_NAME INFORMATION_SCHEMA.SQL_IDENTIFIER,
CONSTRAINT DEFAULT_CHARACTER_SET_NAME_NOT_NULL NOT NULL,
SQL_PATH INFORMATION_SCHEMA.CHARACTER_DATA,
CONSTRAINT SCHEMATA_PRIMARY_KEY PRIMARY KEY ( CATALOG_NAME,
SCHEMA_NAME ),
CONSTRAINT SCHEMATA_FOREIGN_KEY FOREIGN KEY ( SCHEMA_OWNER )
REFERENCES USERS
)

As it could be seen, catalog is part of primary key in SQL3 model.

BTW Why this method is not named getSchemata()?