Category: Java

Apache Maven is distributed in several formats. The simplest way to install Maven is to download a ready-made binary distribution archive and follow the installation instructions. Maven 3.3+ release requires JDK 1.7 or above to execute. General Requirements Java JDK must be installed on system. Java 1.7 or higher is needed for Maven. To verify the […]Continue reading

In this post, I will explain the Merge Sort algorithm and how to use it in Java. Sorting is the process of arranging data in ascending or descending order. Sorting becomes necessary while searching a particular record in database, a particular telephone number in telephone directory, words in a dictionary, and so on. In computer […]Continue reading

So your JUnit 5 tests are not running under Maven? You have JUnit 5 Tests which run fine from your IDE, but fail to run under Maven? Your test output looks like this: [INFO] ——————————————————- [INFO] T E S T S [INFO] ——————————————————- [INFO] [INFO] Results: [INFO] [INFO] Tests run: 0, Failures: 0, Errors: 0, […]Continue reading

It’s a fairly common task as a Java developer to convert from a List to an Array or from an Array to a list. In one of my previous post, I discussed about converting Map to List. Like many things in Java, there is often more than one way to accomplish a task. In this […]Continue reading

In applications, you often need to work with a set of constant values. For example, representing a contract status with the “permanent”, “temp”, and “intern” values, or directions with the “north”, “south”, “east”, and “west” values. In Java, you use the enum type (short for enumeration), a special datatype introduced in Java 5 to represent […]Continue reading

Converting a Java Map to a List is a very common task. Map and List are common data structures used in Java. A Map is a collection of key value pairs. While a List is an ordered collection of objects in which duplicate values can be stored. In this post, I will discuss different ways to […]Continue reading

A common requirement while programming in Java is to convert String to int. UI inputs in Web-based HTML, JSP, or Thymeleaf templates are transferred to backend Java applications as strings. It is the application developer’s responsibility to perform any String to int conversions to fulfill business logic, such as calculating discounts, storing age, and so […]Continue reading

Java Architecture for XML Binding (JAXB) is a library that helps to bind XML schemas and Java representations. JAXB provides you with a mechanism to marshal Java objects into XML and the other way around – unmarshal XML into Java objects. XML is an industry standard for defining the contents of your message. XML along […]Continue reading

One common requirement in Java application is to iterate through the elements of a collection. Prior to Java 8, the three most common ways to iterate through a collection are by using the while loop, for loop, and enhanced for loop. As the Java Collection interface extends Iterable, you can also use the hasNext() and […]Continue reading

Prior to Jackson 1.2, the only way to serialize or deserialize JSON using Jackson was by using one of the following two methods: Adding annotations to modify the POJO classes Writing custom serializers and deserializers Now imagine you want to serialize or deserialize a 3rd party POJO which you don’t have access to its source […]Continue reading