Author: Vijay SRJ
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How to share data across multiple components for a single request in a Spring Boot application?
Let’s say that you make a REST API request to a spring boot web application. There is a security requirement that you need to log the user id across all the method calls in the application for this particular request. Something like this: So , if your application flow starts from a controller class and…
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How to automatically delete rows from Dynamo DB through AWS Cloud formation template?
Let’s say you have built an app which uses AWS Dynamo DB as database. And you have a use case where you want to delete the rows in the table after a certain time , let’s say 1 hour. This can be done automatically! You just need to configure “Time To Live” settings while creating…
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Different ways to do versioning of REST APIs in Spring Boot
Most of our web apps communicate through HTTP / REST APIs. These APIs can evolve over time. And hence maintaining different versions of them can be helpful. For example , lets say you have been hitting a REST API which returns the different products available on an ecommerce store. The owners decide to launch a…
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The Real Benefits of Java Lambdas
Java 8 introduced the concept of Lambda expressions. They provide a concise way to represent functions as objects. A lambda expression is essentially an anonymous function that can be treated as an object and passed around as an argument to methods or stored in variables. Here is an example: In this example, the MathOperation interface…
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Classes in Javascript vs Java
Nothing happens outside a class in Java. To create an object you need a class. Even to print a simple “Hello World” you need a class. That is not always the case with Javascript. You can create objects without using a class. Everything need not be encapsulated within a class! There are similarities between the…
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Different ways to call REST APIs in Spring Boot without additional libraries
In today’s world most modern web apps talk to each other through HTTP APIs. REST API is a popular standard for these HTTP APIs. So calling a REST API from your backend app is a critical functionality. Spring Boot provides multiple abstractions to do this in a simple way. Here are four different ways: Using…
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How to implement Aspect Oriented Programming in Spring Boot?
In your web app , Often you need to implement certain logic which is common across different parts of your application. Like purely technical aspects like logging , security etc. You don’t want to repeat this logic in each part of the code. And you also don’t want to clutter your code by including logic…
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Variables – Java vs Javascript
Variables are critical to any programming language. It is where you store temporary data. Not all data needs to be stored in the database, whatever doesn’t need to be stored in the database and is needed temporarily during your program execution are stored in variables. Variables in Javascript differ from variables in Java in quite…
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Java vs Javascript – Say Hello World!
One of the complaints about Java programming language is that it is verbose. Imagine you are new to programming. And you want to learn to program. The first thing most of us traditionally do is to print “Hello World!” . And to do this in Java you need to go through a lot of ordeal:…
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How to query data in Spring Data through Example?
One of the frequent operations you perform on a database is retrieving data based on certain criteria. Let’s say you have a table containing developer details , their name , experience and their primary technology skill. And you want your app to be able to query this data. There are many ways to do this.…
