The below command can be used to list files in a package in Ubuntu apt-file list <package-name> or dpkg -L <package-name> for example, apt-file list openjdk-8-doc or dpkg -L openjdk-8-doc
国内无法访问google字体api
最新几天发现自己的博客有点问题。就是网页打开特别慢，大概需要花费几十秒的时间。并且页面打开后，网页字体也不对。之前在公司访问自己的页面，没有发现什么问题，不过最近几天在家里访问时，就会出现这个问题。今天周末花了点时间看了一下，发现原来是google字体api服务器又被国家防火墙给屏蔽。
the phases in CMS garbage collector
In the post ‘Brief Introduction to Java Generation Memory‘ and ‘an introduction to young generation collection‘, I described the java generation memory and the young generation collection. In this post I will describe one Java garbage collector, name CMS. CMS,… Read More
normal form for database table
The below normal forms should be enforced when the table of a database is designed. First Normal Form: A table is not in first normal form if it stores multiple values for a piece of information. Action: If a table… Read More
a quick reference to Linux od command
Yesterday my colleague reported a software issue to me. I checked the application logic, but couldn’t find any clue. However, because the software hasn’t been touched for a long time and has passed the testing in the last release, I… Read More
oracle dual table
In Oracle, the ‘select’ statement must have a ‘from’ clause. However, some queries don’t require any table. They just perform some operation or calculation based on some data that is irrelevant to the table. for example, SELECT UPPER(‘hello world’) from… Read More
maven relativePath
maven supports parent-child relationship, where the configuration of the parent project is inherited by the child project. This relationship is specified using the <parent> element as below: <parent> <groupId>com.mygroup</groupId> <artifactId>artifactId</artifactId> <version>1.1</version> </parent> The pom file of the parent project will… Read More
fix ‘could not connect to display’ issue
Today I tried to run foxit reader installer in my Ubuntu Linux as root account. I got the below error message: QXcbConnection: Could not connect to display After struggling for a while, I found the below solution that fix this… Read More
disable password prompt for sudo in ubuntu
After using ubuntu Linux in my xiaomi laptop for months, I find the password prompt really annoying when I try to switch to root account by running the command ‘sudo su -‘. After checking the manual page of ‘sudoers’, I… Read More
disable test in junit5
To disable a test in junit5, using @Disabled annotation in the class or method definition. For example, @Disabled class SortTest { @Test void sortAscTest() { xxxx } } or class SortTest { @Disabled @Test void sortAscTest() { xxxx } }… Read More