博客园 - princessd8251uuid:24b78886-0ed1-41c2-8670-e3f31dcf42c4;id=156082023-11-17T11:08:19Zprincessd8251https://www.cnblogs.com/princessd8251/feed.cnblogs.comhttps://www.cnblogs.com/princessd8251/p/5295965.htmljar包的MANIFEST.MF注意事项 - princessd82511. 基本格式 属性名称:空格+属性值 2. 一行最多72个字符,换行继续必须以空格开头 3. 文件最后必须要有一个回车换行 4. Class-Path 当前路径是jar包所在目录,如果要引用当前目录下一个子目录中的jar包,列入lib目录下的javassist.jar. lib/javassist2016-03-19T10:50:00Z2016-03-19T10:50:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】1. 基本格式 属性名称:空格+属性值 2. 一行最多72个字符,换行继续必须以空格开头 3. 文件最后必须要有一个回车换行 4. Class-Path 当前路径是jar包所在目录,如果要引用当前目录下一个子目录中的jar包,列入lib目录下的javassist.jar. lib/javassist <a href="https://www.cnblogs.com/princessd8251/p/5295965.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/5283854.htmlJava反射使用技巧 - princessd82511. 通过setAccessible关闭安全检查,关闭的目的不是因为访问的field/method是私有的,而且因为关闭后访问公有方法也不会再有安全检查. 2.把已经查找好的method/field 缓存起来,毕竟类的结构一般是不会变化的.2016-03-16T07:46:00Z2016-03-16T07:46:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】1. 通过setAccessible关闭安全检查,关闭的目的不是因为访问的field/method是私有的,而且因为关闭后访问公有方法也不会再有安全检查. 2.把已经查找好的method/field 缓存起来,毕竟类的结构一般是不会变化的. <a href="https://www.cnblogs.com/princessd8251/p/5283854.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/5075776.htmlPage in/Page out/Page fault - princessd8251Paging refers to writing portions, termed pages, of a process' memory to disk.Swapping, strictly speaking, refers to writing the entire process, not j...2015-12-25T06:12:00Z2015-12-25T06:12:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】Paging refers to writing portions, termed pages, of a process' memory to disk.Swapping, strictly speaking, refers to writing the entire process, not j... <a href="https://www.cnblogs.com/princessd8251/p/5075776.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4844584.htmloracle里面base64加解密 - princessd82511. base64 的解密函数select utl_raw.cast_to_varchar2(utl_encode.base64_decode(utl_raw.cast_to_raw('dGVzdA=='))) from dual2. base64 的加密函数select utl_raw.cast_...2015-09-28T09:39:00Z2015-09-28T09:39:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】1. base64 的解密函数select utl_raw.cast_to_varchar2(utl_encode.base64_decode(utl_raw.cast_to_raw('dGVzdA=='))) from dual2. base64 的加密函数select utl_raw.cast_... <a href="https://www.cnblogs.com/princessd8251/p/4844584.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4374882.html开启JMX功能,使JVisvualVM能够连接JVM - princessd8251-Dcom.sun.management.jmxremote.port=1099-Dcom.sun.management.jmxremote.ssl=false-Dcom.sun.management.jmxremote.authenticate=false-Djava.rmi.server.hos...2015-03-28T13:43:00Z2015-03-28T13:43:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】-Dcom.sun.management.jmxremote.port=1099-Dcom.sun.management.jmxremote.ssl=false-Dcom.sun.management.jmxremote.authenticate=false-Djava.rmi.server.hos... <a href="https://www.cnblogs.com/princessd8251/p/4374882.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4329542.html非对称加密 - princessd8251非对称加密算法需要两个密钥:公开密钥(publickey)和私有密钥(privatekey),公开密钥与私有密钥是一对.如果用公开密钥对数据进行加密,只有用对应的私有密钥才能解密;如果用私有密钥对数据进行加密,那么只有用对应的公开密钥才能解密。如下图所示,甲乙之间使用非对称加密的方式完成了重要信息的...2015-03-11T04:24:00Z2015-03-11T04:24:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】非对称加密算法需要两个密钥:公开密钥(publickey)和私有密钥(privatekey),公开密钥与私有密钥是一对.如果用公开密钥对数据进行加密,只有用对应的私有密钥才能解密;如果用私有密钥对数据进行加密,那么只有用对应的公开密钥才能解密。如下图所示,甲乙之间使用非对称加密的方式完成了重要信息的... <a href="https://www.cnblogs.com/princessd8251/p/4329542.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4324495.htmlOracle to_char 转换数值 - princessd8251SQL> Select CONCAT(TO_CHAR('0.001'*100,'990.99'),'%') FROM DUAL;CONCAT(TO_CHAR('----------------0.10%SQL> select to_char(1234567.89,'9,999,999.99') id...2015-03-09T12:59:00Z2015-03-09T12:59:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】SQL> Select CONCAT(TO_CHAR('0.001'*100,'990.99'),'%') FROM DUAL;CONCAT(TO_CHAR('----------------0.10%SQL> select to_char(1234567.89,'9,999,999.99') id... <a href="https://www.cnblogs.com/princessd8251/p/4324495.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4304499.htmlSELENIUM2 使用JavascriptExecutor在页面Javascipt执行 - princessd8251目的:1. 执行一段JS,来改变HTML2. 一些非标准控件无法用selenium2的API时,可以执行JS的办法来取代主要操作:JavascriptExecutor j = (JavascriptExecutor)driver;j.executeScript("alert('hellow rold...2015-02-27T14:49:00Z2015-02-27T14:49:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】目的:1. 执行一段JS,来改变HTML2. 一些非标准控件无法用selenium2的API时,可以执行JS的办法来取代主要操作:JavascriptExecutor j = (JavascriptExecutor)driver;j.executeScript("alert('hellow rold... <a href="https://www.cnblogs.com/princessd8251/p/4304499.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4244393.html用Merge来改写相关更新的例子 - princessd8251下面的两个SQL是等价的,但是一个执行N小时都执行不完,一个花了一分钟。执行计划显示第一个语句是由外面的即将被更新的表驱动内层,相对于是一个NEST LOOP,cost非常大。第二个语句是内层单独执行完后,与外面的筛选结果做一个HASH JOIN, cost降低了很多.UPDATE GPCOMP1....2015-01-23T07:51:00Z2015-01-23T07:51:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】下面的两个SQL是等价的,但是一个执行N小时都执行不完,一个花了一分钟。执行计划显示第一个语句是由外面的即将被更新的表驱动内层,相对于是一个NEST LOOP,cost非常大。第二个语句是内层单独执行完后,与外面的筛选结果做一个HASH JOIN, cost降低了很多.UPDATE GPCOMP1.... <a href="https://www.cnblogs.com/princessd8251/p/4244393.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4211163.htmlOracle --获取绑定变量的值. - princessd8251SELECT * FROM DBA_HIST_SQLBIND WHERE SNAP_ID>67073 AND SNAP_IDSELECT x.ksppinm NAME, y.ksppstvl VALUE, x.ksppdesc describ2 FROM SYS.x$ksppi x, SYS.x$...2015-01-08T07:41:00Z2015-01-08T07:41:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】SELECT * FROM DBA_HIST_SQLBIND WHERE SNAP_ID>67073 AND SNAP_IDSELECT x.ksppinm NAME, y.ksppstvl VALUE, x.ksppdesc describ2 FROM SYS.x$ksppi x, SYS.x$... <a href="https://www.cnblogs.com/princessd8251/p/4211163.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4031341.htmlConvert and Cast for Date and Money format. - princessd8251SELECT REPLACE(REPLACE(@str, CHAR(13), ''), CHAR(10), '')The below script removes the TAB(Horozontal Tab), Line feed(New line), Carriage Return Charac...2015-01-05T17:15:00Z2015-01-05T17:15:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】SELECT REPLACE(REPLACE(@str, CHAR(13), ''), CHAR(10), '')The below script removes the TAB(Horozontal Tab), Line feed(New line), Carriage Return Charac... <a href="https://www.cnblogs.com/princessd8251/p/4031341.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4030044.html使用Mod_JK链接Apache和Tomcat - princessd8251There are many potential problems associated with the default configuration of mod_jk. Let's say it is perfectly adequate for a very low traffic websi...2015-01-05T17:14:00Z2015-01-05T17:14:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】There are many potential problems associated with the default configuration of mod_jk. Let's say it is perfectly adequate for a very low traffic websi... <a href="https://www.cnblogs.com/princessd8251/p/4030044.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4132649.htmlPRAGMA AUTONOMOUS_TRANSACTION - princessd8251转自http://blog.csdn.net/pan_tian/article/details/7675800这段时间遇到一个问题,程序里明明插入了一条记录,但在后边的一段Procedure中却查不到刚刚插入的记录,最后发现这个Procedure的定义中加入了PRAGMA AUTONOMOUS_TR...2014-12-31T06:36:00Z2014-12-31T06:36:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】转自http://blog.csdn.net/pan_tian/article/details/7675800这段时间遇到一个问题,程序里明明插入了一条记录,但在后边的一段Procedure中却查不到刚刚插入的记录,最后发现这个Procedure的定义中加入了PRAGMA AUTONOMOUS_TR... <a href="https://www.cnblogs.com/princessd8251/p/4132649.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4188947.html设置SQLServer的行版本控制隔离级别 - princessd82511.--查询数据库状态 select name,user_access,user_access_desc,snapshot_isolation_state,snapshot_isolation_state_desc,is_read_committed_snapshot_on from sys.dat...2014-12-27T14:49:00Z2014-12-27T14:49:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】1.--查询数据库状态 select name,user_access,user_access_desc,snapshot_isolation_state,snapshot_isolation_state_desc,is_read_committed_snapshot_on from sys.dat... <a href="https://www.cnblogs.com/princessd8251/p/4188947.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4182903.htmlSET TEXTSIZE number - princessd8251When you using sqlcmd to export some data by a query, you will found some column data is truncated if it is a ntext/text/varch(max)/nvarchar(max).the ...2014-12-24T09:30:00Z2014-12-24T09:30:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】When you using sqlcmd to export some data by a query, you will found some column data is truncated if it is a ntext/text/varch(max)/nvarchar(max).the ... <a href="https://www.cnblogs.com/princessd8251/p/4182903.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4158854.htmlOracle 参数之_small_table_threshold - princessd8251SQL> select * from v$version;BANNER-----------------------------------------------------------------------------Oracle Database 11g Enterprise Edition...2014-12-11T17:27:00Z2014-12-11T17:27:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】SQL> select * from v$version;BANNER-----------------------------------------------------------------------------Oracle Database 11g Enterprise Edition... <a href="https://www.cnblogs.com/princessd8251/p/4158854.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4110600.htmlOracle等待事件db file parallel read - princessd8251SQL> select event#,name,parameter1,parameter2,parameter3 from v$event_name where name = 'db file parallel read'; EVENT# NAME ...2014-11-20T06:45:00Z2014-11-20T06:45:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】SQL> select event#,name,parameter1,parameter2,parameter3 from v$event_name where name = 'db file parallel read'; EVENT# NAME ... <a href="https://www.cnblogs.com/princessd8251/p/4110600.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4018958.htmlORA-12631 / TNS-12631: Username retrieval failed - princessd8251From Metalink:Problem Description:====================When your server is not connected to the network and you try to connect inServer Manager (svrmgr...2014-11-02T07:34:00Z2014-11-02T07:34:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】From Metalink:Problem Description:====================When your server is not connected to the network and you try to connect inServer Manager (svrmgr... <a href="https://www.cnblogs.com/princessd8251/p/4018958.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4064060.htmlOracle的Connect By理解 - princessd8251connect by中的条件就表示了父子之间的连接关系 比如 connect by id=prior pid,但如果connect by中的条件没有表示记录之间的父子关系那会出现什么情况?常见的,connect by会在构造序列的时候使用select rownum from dual connect...2014-10-30T17:36:00Z2014-10-30T17:36:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】connect by中的条件就表示了父子之间的连接关系 比如 connect by id=prior pid,但如果connect by中的条件没有表示记录之间的父子关系那会出现什么情况?常见的,connect by会在构造序列的时候使用select rownum from dual connect... <a href="https://www.cnblogs.com/princessd8251/p/4064060.html" target="_blank">阅读全文</a>https://www.cnblogs.com/princessd8251/p/4058436.htmlORA-01436: 用户数据中的CONNECT BY 循环 - princessd8251起始地 目的地 距离(公里)A B 1000A C 1100A D 900A E 400B D 300D F 600E A 400F G 1000C B 600请用SQL语句或一段代码写出从A出发,可达到的目的地(包括间接方式)。create table dest(sid char(1),eid c...2014-10-28T17:08:00Z2014-10-28T17:08:00Zprincessd8251https://www.cnblogs.com/princessd8251/【摘要】起始地 目的地 距离(公里)A B 1000A C 1100A D 900A E 400B D 300D F 600E A 400F G 1000C B 600请用SQL语句或一段代码写出从A出发,可达到的目的地(包括间接方式)。create table dest(sid char(1),eid c... <a href="https://www.cnblogs.com/princessd8251/p/4058436.html" target="_blank">阅读全文</a>