Lalit Mohan Jaimini – Lalit Mohan Jaimini

Allow ufw firewall in ubuntu

enable firewall - sudo ufw enable
reload firewall - sudo ufw reload
disable firewall - sudo ufw disable
allow port ya service - sudo ufw allow port/service-name 
(like - sudo ufw allow ssh 
or 
sudo ufw allow 22
or 
sudo ufw allow from sourceip to any port 22) 
allow rule delete - sudo ufw delete allow port/service-name 
(like - sudo ufw delete allow ssh 
or 
sudo ufw delete allow 22
or
sudo ufw delete allow from sourceip to any port 22)

install ffmpeg in ubuntu

sudo add-apt-repository ppa:jonathonf/ffmpeg-4
sudo apt-get update
sudo apt-get install ffmpeg

Disable apache server status in ubuntu

sudo a2dismod status
sudo systemctl restart apache2.service

Use of Hindi (unicode) character from request parameter in java

String str = request.getParameter("sentence");
System.out.println("before convert - " + str);
str = new String(request.getParameter("sentence").getBytes("ISO-8859-1"),"UTF-8");
System.out.println("after convert - " + str);

Round a double to any decimal places in java

int n = 2;

round(xxxx.xxxxx, n); // Return xxxx.xx

Create username password for apache tomcat user

sudo vi /opt/tomcat/conf/tomcat-users.xml

<role rolename="manager-gui"/>
     <user password="" roles="manager-script,admin" username=""/>
     <user password="" roles="manager-gui,manager-script,admin" username=""/>