When using Keycloak for the authentication of web applications, we will often encounter Web Origin-related errors such as “Access to XMLHttpRequest at ‘http://localhost:8080/realms/huongdanjava/protocol/openid-connect/token’ from origin ‘http://localhost:4200’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.” The reason is that… Read More
OAuth 2.0 Security Best Current Practice recommends that we do not use grant type Resource Owner Password Credentials of OAuth2 but if your application needs to use this grant type, please read this tutorial! I will guide you on how to create and configure the… Read More
Project Reactor with Mono and Flux objects may make it difficult for you to think about how to write Unit Test for reactive code. Actually, this will be solved easily if you use the StepVerifier class of the reactor-test library. How is it in details?… Read More
When you develop an application with different Maven projects, we will often use a Maven parent project to manage these Maven projects. It will help us to centralize the version management of the dependencies used for the application, when we want to upgrade the version… Read More
PostgreSQL is an open-source object-relational database system. We have different ways to install PostgreSQL server on many different environments, as well on macOS. In this tutorial, I will show you a way to install PostgreSQL server on macOS using Postgres.app! First, you need to go… Read More
To use applications that use Keycloak for authentication and authorization, we need a user to log in. Usually, in large systems, the user information will be stored in Active Directory (AD) or LDAP, Keycloak can connect to these systems to retrieve user information. It can… Read More
Clients in Keycloak are applications that interact with it for authentication and authorization. Adding a new client in Keycloak is letting it manage all clients that will connect to it, according to which protocol, which standard authentication and authorization. In this tutorial, I will show… Read More
Realm is a concept in Keycloak that refers to an object managing a set of users along with their credentials, roles and groups. A user in Keycloak belongs to only one realm and the user who logs in to Keycloak will log into that user’s… Read More
Keycloak is an open-source software for managing access for any application. It supports many different authentication and authorization standards such as Single Sign-On (basically, we can use our login information for many different applications), OpenID Connect, LDAP, and more … In this tutorial, I will… Read More
Previously, when declaring a multi-line text in Java, for example:
|
1 2 |
Welcome to Huong Dan Java My name is Khanh |
We will usually declare the following:
|
1 2 |
String text = "Welcome to Huong Dan Java \n" + "My name is Khanh"; |
Result: But from Java 13 onwards, you do not need to declare so anymore. Java now supports the text blocks with the ability to declare multiple lines… Read More
