通过JAVA设计 GUI 界面的计算器程序，用户可以通过鼠标依次输入参加计算的数值，进行加、减、乘、除等混合运算,这些完成标准计算器的基础操作。当选择科学计算器后，可以实现sin 、 cos 、 tan 、 ln、x^y、x^2、x^3、pi、n!、mod和十六进制除这个以外还可以删除输入，清空结果，求1除X，X百分比，十进制是，八进制，二进制的相互转换。
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001328s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.103962s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001202s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.002048s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001648s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.005746s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001587s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.006866s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.019246s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001750s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 544936 [ RunTime:0.019365s ]
