java statement isclosed bug??

PreparedStatement insertlogstmt=null;

try{

......

}catch(Exception e){

.....

}

finally {

try {
if (insertlogstmt != null&&(!insertlogstmt.isClosed())) { ##it will return ,but why
insertlogstmt.close();
}
} catch (Exception e) {
e.printStackTrace();
}
try {

if (m_conn != null&&!m_conn.isClosed()) {

m_conn.close();

logger.debug("SynVoltdb Log logForvoltdb m_conn is not null and closed");
}

} catch (SQLException sqle) {

}

}