应用背景这是一个基于Java编写的带有过程保存功能的计算器，使用了Swing界面，有文件保存功能，是一个很实用的软件，同时本项目也非常适合新手用来学习Java语言。关键技术本项目运用了继承了JFrame类以及使用了ActionListener接口，在计算过程保存功能的实现中使用了JFileChooser的对象:JFileChooser chooser = new JFileChooser();，保存文件的默认格式是txt：file = new File(file.getParent(),file.getName() + ".txt");
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计算器（保存计算过程） .classpath .project .settings bin src 计算器（保存计算过程）.jar
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001200s ]
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:0.066671s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001309s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001562s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001152s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003307s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000838s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003775s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014750s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001419s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 48619 [ RunTime:0.021116s ]
