Categories
Article

Install Jenkins on Ubuntu 20

CI/CD is now an integral part of the software development as we need to release changes to the market very frequently. For the implementation of the CI/CD, Jenkins is the most used software and has various plug-ins and large community support. Jenkins is a Java-based server for build, test and deploy applications automatically, this can […]

Categories
Article

Apache Cassandra Installation on Ubuntu

Apache Cassandra is a fault-tolerant, highly scalable, very reliable, and performant NoSql database system. It is free open-source, fully developed using java can run on any JVM-based system. Installation of the Cassandra database is very straightforward. One can just download unzip precompiled binaries and run if they have all the prerequisites to run them. For […]

Categories
Java

Using AWS Credentials with Service Client in Java Spring

AWS provides Java SDK to make requests to Amazon Web services. Using SDK we can make requests and perform the different operations of AWS services. We need to provide AWS credentials while making requests, by default SDK tries to use the default credentials configured on the host. There are various ways to provide credentials to […]

Categories
Java

Sorting Object By one or More Properties in Java

While working with arrays or lists or any other collection in java, many times we need to sort elements. For primitives and strings, it can be straightforward. But for customer objects, we need to write Comparator or implement a Comparable interface. If you are dealing with objects without Comparable interface or you need to perform […]

Categories
Java

Most Efficient Way to Search Element in Java Array

Using core java we can search an element in an array in many ways. For searching in arrays of primitive or Objects, some methods are common for both and some can be used with in primitive type arrays. 1- For me most efficient method is using Arrays.binarySeach method. It provides an overloaded version for all […]

Categories
Java

8 Ways to Iterate Each Entry of Java Map

Java collection framework has Map interface and several implementation classes like HashMap, LinkedHashMap, TreeMap, ConcurrentHashMap. Map one of the most used interface used to store and operate on key-value pairs. To iterate all entries of a Map, there are several ways as given below. 1- Using foreach and entrySet method 2- Using map.forEach method 3- […]

Categories
Java

Parsing String to Int in Java

Converting a string number to int in java can be done using several ways. We can use the java Integer class pasrseInt and valueOf methods. We can create of util method to do this with exception handling. Integer num = Integer.valueOf(input);// orint num = Integer.parseInt(input);There is a slight difference between these methods: valueOf returns a […]

Categories
Java

Best ways to create ArrayList from Array in Java

Many times we need to create an ArrayList from arrays of objects in java. There are several ways to do this using core Java APIs or third-party open-source libs like guava. The easiest way to do this is by using the JDK Arrays class. Using JDK to convert array to ArrayList But the above one […]

Categories
Java

Convert InputStream to String in Java

While writting Java programs much time we need to convert an InputStream object to a String. There are many ways to do this, we can use core Java classes or we can use some really good java libraries to convert InputStreams to String. Apart from JDK, Apache Commons IO, and Guava provides classes to convert/read […]

Categories
Java

Which Java Collection Class to Implement LRU Cache?

A cache is a method to store some data temporarily which can be accessed faster to improve software performance. There can be different types of cache but in general, we use LRU (Least recently used entry will evict first in case of cache size full) and cache with TTL (Time to live, entries will be […]