java怎麼判斷表是否存在？

public boolean validateTableNameExist(String tableName) {
           int tableNum = jdbcTemplate.queryForInt("SELECT COUNT(*) FROM ALL_TABLES WHERE TABLE_NAME=" + tableName);
           if (tableNum > 0) {
                 return true;
           }else {
                 return false;
           }
     }

public boolean validateTableNameExist(String tableName) {
         Connection con = getYourCnnection;
         ResultSet rs = con.getMetaData().getTables(null, null, tableName, null);
         if (rs.next()) {
               return true;
         }else {
               return false;
         }
     }

select count(*) from User_Tab_Columns where  table_name='TABLENAME' and column_name='COLUMNNAME';

select count(*) from all_tables where table_name='TABLENAME';