Take a look at my project http://code.google.com/p/db2-scheme2ddl/ for code samples. I can get table DDL for IBM DB2 with pure JDBC.
In short,
- Invoke undocumented DB2 function CALL SYSPROC.DB2LK_GENERATE_DDL('-e -z SAMPLE', ?)
- Store second INOUT parameter for later use
Find primary object's DDL with query
select OP_SEQUENCE, SQL_STMT, OBJ_SCHEMA, OBJ_TYPE, OBJ_NAME, SQL_OPERATION FROM SYSTOOLS.DB2LOOK_INFO where OP_TOKEN=? and OBJ_SCHEMA=? and OBJ_TYPE=? and OBJ_NAME=?