Delete more than one table

String query = "show tables like 'a%'";
String tables = null;
try {
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery(query);
 
while (rs.next()) {
String tableName= rs.getString(1);
if (tables == null) tables = tableName;
else tables += "," + tableName;
}
st.close();
 
st = conn.createStatement();
st.executeUpdate("drop table " + tables);
st.close();
} catch (SQLException e) {
System.out.println("Unable to execute Query " + e.getMessage());
}