Execute linux bash command and read its output from java Program

This is a very frequent snippet that you want and spend a lot of time researching on the basic technique. Following is the java code snippet.

Parsing the response headers in Java from URLConnection object

Often when doing programming with HTTP requests and responses there would be headers that would be sent via URLConnection object.

A generic  java snippet to parse the headers are like this.

Mathematical puzzles to motivate a programmer

Off late have encountered multiple instance wherein, some high end technological innovations are spurred from basic mathematically theory.

Loads of links point at this piece of crucial skill.

Some links that you could follow are:

Math Puzzles

Good repository to exerice your brain.

MURDEROUS MATHS BRAINBENDERS

Missionaries and cannibals problem - Wikipedia, the free encyclopedia

Portal:Mathematics/Featured picture archive - Wikipedia, the free encyclopedia

Basis for Cube processor techincal thought you gave and inked on 13 OCT 2012

Menger sponge - Wikipedia, the free encyclopedia

List of fractals by Hausdorff dimension - Wikipedia, the free encyclopedia

Polygramme Isarel flag derived by fractals

Index et notations courbes planes

plane symmetries

plane symmetry groups

Fill-It-In Outline Mathematics

Fill-It-In Outline Mathematics: a few dozens word problems in arithmetic, geometry, algebra, logic - all in an outline These are some brain teaser games on iPhone

IXL - Fourth Grade Math Practice

IXL is the Web's #1 math practice site. The 4th grade level provides unlimited practice in 200+ math skills in a colorful, fun environment.

Java | Programming Challenges – Puzzles – Algorithms – Solutions

Generator Matrix -- from Wolfram MathWorld

Venn Diagram -- from Wolfram MathWorld

Solved Problems -- from Wolfram MathWorld

Tapping Into the Power of GPU in Mathematica « Wolfram Blog

Mathematica's GPU programming integration is the full automation of the GPU function developing process. Write, compile, test, run code in a single step.

10 Puzzle Websites to Sharpen Your Programming Skills

Here are the top 10 popular programming puzzle sites that will help test your thinking and improve your programming, problem solving, and logical thinking skills.

Coding Horror

Evil Mad Scientist Laboratories | Making the world a better place, one Evil Mad Scientist at a time.

The Cathedral and the Bazaar - Wikipedia, the free encyclopedia

The Cathedral and the Bazaar

Math puzzles solution

Sam Loyd's Cyclopedia of Puzzles 

 

Enjoy playing with numbers.

 

Programming technologies vs OSI layer stack

The following is a rough diagram that visualizes a understanding of my various web programming techniques to pure theoretical categorization of OSI network  models  

Give this a thought and life-cycle of individual technologies and you find a cohesiveness of basic concepts.
Good References 
[1]
https://www.sciencedirect.com/topics/computer-science/network-architecture
[2]
https://www.sciencedirect.com/topics/computer-science/layer-architecture 

[3] Spatial Networks  
https://www.tandfonline.com/doi/pdf/10.1080/24751839.2017.1295601


This will help in IoT and emerging technologies solution design in 2020 and years to come

Software product consideration

Just thought of visualizing various software attributes that came across.

You may want to revolve around these terms and see map them to your experience on various projects you worked upon.
- How some products focused only on selected few; drawbacks that they encountered down the lane ; etc
   Examples1) i18n for Qt 3.0 had no support for i18n
                 2) Security bolting on initial version of Windows OS
                 3) Web application ( RIA ) lacked automate ability considerations
 

Java snippet to open, modify and write back to same file

Objective :
Very often you find this requirement. Sometimes you try and overcome using linux commands rather than going by the Java programming technique.

Here is a snippet that would be handy.

 public static void main(String[] args) throws IOException {
   
    // Read XML as string
    byte[] buffer = new byte[(int) new File(args[0]).length()];
    FileInputStream f = new FileInputStream(args[0]);
    f.read(buffer);
   
    // format it
        String unformattedXml = new String(buffer);
        String formattedXml = new XmlFormatter().format(unformattedXml);
       
    // Write formatted string back into same file        
        FileOutputStream pOUTPUT;
        PrintStream pPRINT;
        pOUTPUT = new FileOutputStream(args[0]);
        pPRINT = new PrintStream(pOUTPUT);
        pPRINT.println (formattedXml + "\n");
        pPRINT.close();
        System.out.println(    formattedXml );

}


Found this handy even after experience in Java programmer.

Small end webserver that can meet up to aspirations of self-owned website

'Small end webserver that can meet up to aspirations of self-owned website'

Which is it ? It is Apache Tomcat . A web server ( not a full-fledged J2EE container ) but can meet up to most of your needs.

Off-late you may wonder on the kind of technical support from user community might be not very easy to get. But I was wrong.

https://blogs.apache.org/tomcat/
gives you very good support.
With respect to debugging the webserver is concerned . Never thought it would be so easy to do it on a  local machine.
Its so easy to do it, with Tomcat 7 - JMX - Sun JConsole

TOMCAT 7 - JMX - SUN JDK JConsole

STEP -1 ] Install SUNJDK 1.6+ or above
STEP -2 ] Install SUNJRE 1.6+ or above
STEP -3 ] Install TOMCAT 7.0 or above

STEP -4 ] Set the ENV properties
Linux platform
$ CATALINA_OPTS="-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=8999 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false -Djava.rmi.server.hostname=test-idc.internet2.edu";
$ export CATALINA_OPTS;

On Windows
In envirnoment variables
create CATALINA_OPTS
-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=8999 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false -Djava.rmi.server.hostname=localhost


STEP -5 ] Start Tomcat
C:\tomcat70\bin\Tomact7.exe

STEP -6 ] Start JConsole
C:\SUNJDK16\bin\jconsole.exe

STEP -7 ] Connnect to local PID of tomcat process.
Reference :
https://wiki.internet2.edu/confluence/display/CPD/Monitoring+Tomcat+with+JMX

 Thanks Apache Foundation.