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Resource Pooling

Requirements for Resource Pool: Allow threads to access resources concurrently Should block threads if no resource is available at the moment Maintain a pool of initialized resources to allow reuse and avoid costly initialization of resources Classes from java.util.concurrent package that will be used: ConcurrentLinkedQueue - An unbounded thread-safe queue. This collection is ideal to act as container of resources since it provides concurrent non blocking access to its elements. Semaphore - Semaphore maintains a set of permits by having a counter. This can be used to acquire or release a permit. If no permits are available then acquire() blocks the invoking thread. Implementation Code reference on github: Resource Pooling

DIY Testing Portal

Introduction A simple portal for tracking testing reports, bugs found and then mapping all this way back to features and releases. However JIRA and other such project management tools provide the features that are mentioned in this document but still this solution can come in handy for those who don't want an outside tool rather a quick dirty solution. Note this is for a general solution overview and focuses more on data modelling. Any installation and setup related findings is homework for reader :) What all is compassed in testing ? Testing Report Bugs Releases Features Test cases Environment What all do you need to see in a testing dashboard ? Timeline of all testing that has happened till date Individual testing report Test cases, which cases map to which feature(s) Testing cycles for a specific release Bugs introduced in a release, mapped to which feature(s) The portal solution involves : Mongodb Mongodb Compass - mongodb dashboard tool Elas

Enabling CXF goodies in Spring Boot

In this post we are going to add some of the CXF features to our existing app that we developed in  previous post . These features are : ID Logging Jackson Provider for POJO to JSON conversion Swagger 2 documentation Step 1: Configuration class Create a RestServer class in config package as shown below package org . blog . config ; import com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider ; import org.apache.cxf.feature.LoggingFeature ; import org.apache.cxf.jaxrs.swagger.Swagger2Feature ; import org.springframework.context.annotation.Bean ; import org.springframework.context.annotation.Configuration ; /** * Created by Anand_Rajneesh on 3/23/2017. */ @Configuration public class RestServer { @Bean public JacksonJsonProvider jsonProvider (){ return new JacksonJsonProvider (); } @Bean public LoggingFeature loggingFeature (){ return new LoggingFeature (); } @Bean public Swagger2Featur

Guide : Spring Boot with Apache CXF for REST services

In this series of guide, we are going to explore writing REST services with Apache CXF using Spring Boot. The project is build using maven. I assume that you already know how to use maven. Step 1 : Adding dependencies for Spring Boot By default you have to inherit the parent pom of spring boot, but that cannot be followed everytime, so I use an alternative to that. I basically add spring boot pom as dependency so that it brings all the dependencies. <properties> <>UTF-8</> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <spring.version>1.4.3.RELEASE</spring.version> <cxf.version>3.1.10</cxf.version> </properties> <dependencies> <dependency> <!-- Alternative to inheriting from parent spring pom --> <groupId>org.springframework.boot&l

OOPs simply explained

What is OOPs ? It is Object Oriented Programming. It comprises of Polymorphism Encapsulation Inheritance Abstraction Already lost me ? Now here it is read about OOPs as if you deal with it every day. Let's take at OOPs from a Corporate world point of view. There is an organization which comprises of several employees which form a hierarchy. Now every employee has their way of working, some work hard, some like to delegate and some are smart. Though everyone does work in office, they do it in their own way. This is Polymorphism (implementing a function differently while keeping the semantics of function same). Employees are after all humans, we all have secrets. We have our own perspective which we may or may not share with everyone i.e. we have state and behavior only accessible to us. We share some of our secrets with our closest friends, some of our perspective to a group of people depending upon our status. In the end we do keep everything close and private, nothing

PL SQL Cheatsheet

PL/SQL Syntax for reference Basic PL/SQL block DECLARE --variable declarations go here BEGIN --program logic goes here END; Functions -  Named pl/sql blocks mainly used for computation and not for write operations. They return value to the caller as defined in function. CREATE OR REPLACE FUNCTION myFunc( arg1_in IN VARCHAR2, arg2_in VARCHAR2) RETURN BOOLEAN AS RETURN true; END; Procedure - Named pl/sql block used for write operations. CREATE OR REPLACE PROCEDURE myProc( arg1_in IN VARCHAR2, arg2_in IN VARCHAR2) AS arg3 VARCHAR2(2048); arg4 BOOLEAN; BEGIN --logic END; Variable Declarations  arg VARCHAR2(2048) := 'myString'; arg BOOLEAN := true; arg NUMBER := 10; IF ELSE Conditions IF (condition) THEN --logic 1 ELSIF (condition2) THEN --logic 2 ELSE --logic3 END IF; SWITCH Statements With selector arg1 NUMBER := 0; CASE arg1 WHEN 0 THEN --lo

Power of declarative syntax of Lambda

Since Java has introduced lambda, writing code has become a breeze especially when it comes to expressing what you want to computer to do rather than how to do it. The following is a question from Project Euler and is solved using lambdas in Java8. Let d( n ) be defined as the sum of proper divisors of n (numbers less than n which divide evenly into n ). If d( a ) = b and d( b ) = a , where a ≠ b , then a and b are an amicable pair and each of a and b are called amicable numbers. For example, the proper divisors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55 and 110; therefore d(220) = 284. The proper divisors of 284 are 1, 2, 4, 71 and 142; so d(284) = 220. Evaluate the sum of all the amicable numbers under 10000.  A simple brute force solution is to check every number from 2 to 10000 and if its  an amicable number then add it to sum. Listing it in steps you are basically doing 3 things: Take numbers from 2 to 10000 If number is amicable Add it In Java 7 one will