java tutorial: java get timestamp milliseconds
Java get timestamp milliseconds : 1.System.currentTimeMillis(); 2.Calendar.getInstance().getTimeInMillis(); 3.new Date().getTime();...
Use FileWriter class to write files in Java
The FileWriter class extends from the OutputStreamWriter class. This class writes data to the stream character by character. You can create the required objects through...
java tutorial: Java enum check if value exists
Java enum check if value exists: 1. Enum class provides inspection methods 2. Check with for loop 3.Use stream iterators 4.Use a tool class similar...
vim tutorial: vim delete line
Vim delete lines, as the basic knowledge of vim is one of the functions we must master. Mastering the skills of deleting lines can improve...
How to display full path/absolute path with ls command
linux ls full path, you can use the ls -d option combined with the environment variable $PWD. syntax: ls -d $PWD/*...
awk replace statement and examples
Awk replace statement can help us format the input data conveniently. Use of awk string manipulation functions: gsub() ...
man command tutorial in linux/unix with examples
Man command in Linux/unix is used to display the user manual of any command we can run on the terminal....
help command tutorial in linux/unix with examples
Help command can help you understand any built-in commands in linux/unix. Syntax: help name, name: built-in function name....
MySQL tutorial: use variables to generate row numbers for each row
Mysql row number - we can implement it through variables. mysql> set @id = 0;mysql> select @id := @id + 1 as id ......
MySQL tutorial: column to row use group by and group_concat function
Mysql column to row - use group by the data set, and then associate the column data through the group_concat function....
vim tutorial: vim copy, cut and paste
This article will show you how to use vim to copy-paste and cut-paste in normal mode. ①y stands for copy ②p stands for paste ③d...
java tutorial: Java Generic
Java generics, in a nutshell, generics enable types (classes and interfaces) to be parameters when defining classes, interfaces and methods....
5 ways to get command help in linux/unix
How to get command help while working on Shell ? 1.command -h or --help 2.man command 3.help command 4.info command 5.whatis command ...
java tutorial: 5 ways to create stream in java 8
A java stream is a sequence of objects, which can be arranged, filtered, and transformed through a pipeline to produce the desired result....
java tutorial: Java exception
A java exception is an event that occurs during the execution of a java program that disrupts the normal flow of instructions....