SEARCH KEYWORD -- Problem solving


  Convert JKS to BKS using keytool

There are lots of questions(question 1, question 2) on Stackoverflow about how to convert JKS keystore to BKS keystore(a keystore format provided by BouncyCastle) using Java keytool.  The reason why this conversion gets lots of questions is that BKS is not a keystore format supported by Java SE, it's a third party keystore format. To convert JSK to BKS, the BKS provider has to be downloaded first. And a few more options needs to be added when running the keytool command. The typical co...

   JKS,BKS,KEYTOOL,JAVA,SECURITY     2016-07-14 03:49:52

  Install both 32 bit and 64 bit WAMP server

WAMP server is a platform tool for serving PHP applications on Windows. It includes a combination of Apache, MySQL and PHP service which can help developers test or run PHP applications with minimal setup. Sometimes one would first have a 32 bit version of WAMP installed and a few applications have been configured. But later s/he would mistakenly installed a 64 bit version of WAMP and somehow the 32 bit version configuration is overwritten. This causes a problem where the old applications config...

   PHP,WAMP,64 BIT,32 BIT,MULTIPLE VERSION     2017-03-18 01:14:21

  malloc/free and new/delete in C++

malloc and free are C++/C language standard library functions, while new/delete are operator of C++. They can be used to allocate dynamic memory and free memory in C++ programs malloc/free can not meet the requirements of dynamic objects creation. Object needs to call the constructor to initialize the object when creating, the object needs to call the destructor before it is destroyed  Since malloc() and free() are library functions rather than operators, the compiler has no control permiss...

   C++,memory,malloc,free,new,delete     2012-06-20 06:52:09

  Resolve high CPU usage issue caused by file_get_contents in PHP

Sometimes a Linux server which runs Nginx + PHP-CGI(php-fpm) web service may experience sudden system load increase and the CPU usage is around 100% for many php-cgi processes when checking with top command. If this happens, file_get_contents may be the cause if it's used in the PHP script. In lots of web applications, normally there are lots of API requests based on HTTP. Many PHP developers like to use file_get_contents("http://example.com/") to get the API response because it's simple to...

   PHP,FILE_GET_CONTENTS,PHP-CGI     2018-11-09 21:35:00

  Advantages and disadvantages of GoLang

GoLang is a strong typed language which means it is less flexible than interpreted languages by nature. But Go provides Any type(interface) and Reflect mechanism which make the language very close to interpreted languages on flexibility. More and more people start to learn GoLang. This post is mainly for listing down some of the advantages and disadvantages of GoLang. Advantages Performance(Machine code) GoLang is a compilation language which can be compiled to machine code and the compiled bina...

   GENERICS,GOROUTINE,GOLANG,DISADVANTAGE,ADVANTAGE     2018-11-10 20:46:45

  Get Bluetooth back on my ASUS Zenbook UX31A

A strange thing occurred to me a few days ago after I installed some routine Windows updates on my ASUS Zenbook UX31A, my Bluetooth was gone and I could not have my Bluetooth speaker connected to my PC and listen  my favorite music. It's just like a ghost, everything disappears all of a sudden. Everything was tried to find where my Bluetooth went but no luck. Below is what my device manager shows: No Bluetooth is found, usually if there is some issue with the Bluetooth driver, the device m...

   Bluetooth,Windows 8.1,ASUS Zenbook, Bluetooth driver     2014-12-11 09:17:11

  Fix External Monitor Flickering on MacBook M4 Pro

Recently got a new MacBook M4 Pro and everything works fine until one day suddenly noticing the screen started to be flickering and never stops, realizing it might be some problem happening, so started to try to see whether it's just a glitch or persisting issue. Tried to do following: Turn off the external monitor off and then on Plug out the HDMI cable of the external monitor and plug in back Restart the MacBook M4 Pro These all failed to work, the issue still happens. So was following diffe...

   MACBOOK M4,MONITOR FLICKERING     2024-11-19 21:31:16

  Mozilla releases a web identity system : Persona

Now almost every website requires the user to register, there are many benefits of registration for a website, such as retaining users, accommodating discussions, providing customized content and so on.But there is too much trouble if each site requires registration, right?Of course, users can also have their own way, for those less important sites, for example, using a unified user name, password and email so that you only need to remember one account. Then, we also see some advanced methods em...

   Mozilla,Persona,Security,ID     2012-09-28 12:02:25

  One reason why mcrypt responds slowly

This morning one colleague came over and talked about one script which used mcrypt responded very slowly, the server configurations are fine. But the reason for the slowness is unknown. Here is one script which reproduces the issue: <?php $dmcryptText = "dummy"; $key = "foobar"; $size = mcrypt_get_iv_size(MCRYPT_BLOWFISH,MCRYPT_MODE_ECB); $iv = mcrypt_create_iv($size); //Take care $m = mcrypt_ecb(MCRYPT_BLOWFISH, $key, $dmcryptText, MCRYPT_DECRYPT, $iv); var_dump($m); When 20 requests of&...

   SOLUTION,SLOW,MCRYPT,RESPONSE,PHP     2012-09-27 12:03:16

  Facebook's new milestone : 1 billion active users per month

Social network giant Facebook's monthly active users reach a new milestone -- 1 billion, this means 1 out serven people on earth is using it. Facebook CEO Mark Zuckerberg announced this news in an open letter. He wrote : This morning, there are more than one billion people using Facebook actively each month.If you're reading this: thank you for giving me and my little team the honor of serving you.Helping a billion people connect is amazing, humbling and by far the thing I am most proud of in m...

   Facebook, Active user,Milestone     2012-10-05 05:02:32

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