No you can't. What are you expecting to get by calling statement.execute(...)?
It returns one ResultSet (... which means one table).
You can just call "select fullName from user where user_id in (1, 2)" to geht back both results.
Having semicolons in JDBC statements is very error prone in general. Some JDBC drivers do not support this (e.g. IBM's JDBC driver for DB2 10.x throws an exception if you close your SQL statement with ";").
