If you google for "jdbc bulk update" you'll get lots of results like this one or this one.
The latter has an example like this:
try {
...
connection con.setAutoCommit(false);
PreparedStatement prepStmt = con.prepareStatement(
"UPDATE DEPT SET MGRNO=? WHERE DEPTNO=?");
prepStmt.setString(1,mgrnum1);
prepStmt.setString(2,deptnum1);
prepStmt.addBatch();
prepStmt.setString(1,mgrnum2);
prepStmt.setString(2,deptnum2);
prepStmt.addBatch();
int [] numUpdates=prepStmt.executeBatch();
for (int i=0; i < numUpdates.length; i++) {
if (numUpdates[i] == -2)
System.out.println("Execution " + i +
": unknown number of rows updated");
else
System.out.println("Execution " + i +
"successful: " numUpdates[i] + " rows updated");
}
con.commit();
} catch(BatchUpdateException b) {
// process BatchUpdateException
}