addBatch and executeBatch

[jacq carballo]

are the addBatch and executeBatch commands thread-safe? i mean, if i have 10 threads adding sql statements to the addBatch methods, and then i suddenly made an executeBatch (after 20 sql statements added to the batch). will the next input to addBatch affect the executeBatch.
for example, if the executeBatch is alrd executing the 20 sql statements and one thread adds 1 sql statement to the addBatch, will the executeBatch execute 21 sql statements or just the 20 sql statements?
tia
jacq