Sorting, searching, and binary search Divide-and-conquer Dynamic programming and memorization Greedy algorithms Recursion Graph traversal, BFS and DFS Sorting Main algorithms presented Mergesort: Java sort for Objects Quicksort: Java sort for primitive types Heapsort Mergesort vs Quicksort vs Heapsort All these algorithms have O(N log N) average time complexity, though quicksort is O(N2) in the…
Good knowledge of common data structures is needed in computer science. This article describes common data structures, and present cost and benefits. Lists A List is an abstract data type representing a finite collection of ordered elements. Typically, a List is allocated dynamically depending on the implementation. For example, Array-based lists allocate elements in contiguous…
You use maven in Eclipse, and need to work with multi-module (hierarchical) projects? This page shows how to create and work with maven multi-module projects in Eclipse. For this article, I am using eclipse-jee-2019-06, which already supports maven. If you use a different version of eclipse, make sure the m2e plugin is installed (+m2e-wtp for…
Here are three examples covering maven basics in Eclipse such as: convert a java project to maven nature, create a project with an archetype selection, and refresh/update projects and understand files and structure. For the article, I use eclipse-jee-2019-06, which already provides maven support. If you use a different version of eclipse, ensure the m2e…
You need to import folders of your filesystem into Eclipse? Some possible motivations: You want to perform a full-text search on a directory in the filesystem You want to see the content of an existing project without importing it Assuming you have temp project, where you want to import the filesystem. Select from menu File…
Notes on practical usage of Java 8 stream filtering. Stream Filtering A Stream<T> references a sequence of T values, and exposes a set of aggregate operations we can use to manipulate data in a pipeline. As an example, we can find the name of any people older than 20. In java, you can loop on a variable using the…
Here are some notes on parsing XML file with java to extract information Simple Example Assume we have an XML file and we want to extract specific attributes. A sample file could be: With XMLStreamReder Here is the code to quickly scan the XML file and get the values for the id and date attributes….
This page presents a few examples of using Java for passwords and hashing. Generate Password A Java example to generate a random password containing only alphanumeric characters. Java Code to ComputeSHA-512 digest other.. linux get sha-512/
Here are a few notes on how to run a simple java REST service and return JSON data as a response REST service to do provide data on products REST with jax-rs using Jersey We start creating a StoreContent class representing the products in an online store. Then, we add a container for our contents…
Knowledge of algorithms and data structures is important for Software Engineers. To be good at solving problems you need practice. Here is some resource to make practice, and suggestions. Posts about Algorithms Below, you see the list of my posts about algorithms [catlist name=”algorithms”] Sites Sites to practice and learn algorithms and competitive programming LeetCode…