Java LinkedList Tutorial
Java LinkedList is a doubly linked list implementation of Java’s List and Deque interfaces. It is part of Java’s collections framework. Here is the class hierarchy of LinkedList Following are some key…
Generate Parentheses
Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses. For example, given n = 3, a solution set is: "((()))", "(()())", "(())()", "()(())", "()()()"…
Longest Substring with At Least K Repeating Characters
Longest Substring with Repeating Characters - Find the length of the longest substring T of a given string (consists of lowercase letters only) such that every character in T appears…
Longest Valid Parentheses
Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring. For "(()", the longest valid parentheses substring is "()", which…
Valid Parentheses
Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. The brackets must close in the correct order, "()"…
Diagrams for Understanding Java
A diagram is sometimes worth 1000 words. The following diagrams are from Java tutorials on Program Creek, they have received the most votes so far. Hopefully, they can help you review what…
What does a Java array look like in memory?
n Java, an array stores either primitive values (int, char, ...) or references (a.k.a pointers) to objects. When an object is created by using "new", memory space is allocated in…
Spring MVC and the @ModelAttribute Annotation
1. Overview One of the most important Spring-MVC annotations is the @ModelAttribute annotation. The @ModelAttribute is an annotation that binds a method parameter or method return value to a named model attribute and then exposes it…
Spring @RequestParam Annotation
Overview In this quick tutorial, we’ll explore Spring's @RequestParam annotation. Simply put, we can use @RequestParam to extract query parameters, form parameters and even files from the request. We’ll discuss how to use @RequestParam and its…
Spring RequestMapping
Overview @RequestMapping is one of the most common annotation used in Spring Web applications. This annotation maps HTTP requests to handler methods of MVC and REST controllers. In this post,…