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Posts on Home https://gustavopeiretti.com/post/ Recent content in Posts on Home Hugo -- gohugo.io hola@gustavopeiretti.com (Gustavo Peiretti) hola@gustavopeiretti.com (Gustavo Peiretti) Fri, 02 Feb 2024 00:00:00 +0000 Spring Boot Rest Error Handling with Controller Advice https://gustavopeiretti.com/spring-boot-rest-error-handling-controller-advice/ Fri, 02 Feb 2024 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-rest-error-handling-controller-advice/ <p>Here we are going to understand how to manage errors in Spring Boot Rest applications.</p> SOLID principles with examples https://gustavopeiretti.com/solid-principles-with-examples/ Thu, 21 Dec 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/solid-principles-with-examples/ <p>SOLID is the acronym for five basic principles that intend to make software design it is simpler and easier to understand and also reduces maintenance costs.</p> SOLID Dependency inversion principle https://gustavopeiretti.com/solid-dependency-inversion-principle/ Wed, 20 Dec 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/solid-dependency-inversion-principle/ <p>According to this principle, Dependency Inversion Principle (DIP), there should be no dependencies between modules, especially between low-level and high-level modules.</p> SOLID Interface segregation principle https://gustavopeiretti.com/solid-interface-segregation-principle/ Wed, 20 Dec 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/solid-interface-segregation-principle/ <p>This principle about Interface segregation principle (ISP) says that any client should not be required to depend on methods they do not use.</p> SOLID Liskov substitution principle https://gustavopeiretti.com/solid-liskov-substitution-principle/ Wed, 20 Dec 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/solid-liskov-substitution-principle/ <p>The Liskov substitution principle (LSP) is an object-oriented design principle that states that a subclass must be interchangeable with its superclass without changing the program’s behavior.</p> SOLID Open/closed principle https://gustavopeiretti.com/solid-open-close-principle/ Wed, 20 Dec 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/solid-open-close-principle/ <p>The open/closed principle (OCP) says that every class, module, method, etc. should be open for an extension but must be closed for modification.</p> SOLID Single responsibility principle https://gustavopeiretti.com/solid-single-responsibility-principle/ Wed, 20 Dec 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/solid-single-responsibility-principle/ <p>This principle refers to the unique responsibility that each program should have with a specific and limited task.</p> Design patterns you should know https://gustavopeiretti.com/design-patterns-you-should-know/ Sun, 20 Aug 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/design-patterns-you-should-know/ <p>Design patterns help us to create robust applications by solving common problems using known and proven solutions.</p> Adapter Design Pattern https://gustavopeiretti.com/adapter-design-pattern/ Sat, 19 Aug 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/adapter-design-pattern/ <p>The Adapter design pattern works when you have different or incompatible interfaces, and you need the client to use both in the same way.</p> <p>The Adapter design pattern says in its definition that it converts an interface or class into another interface that the client needs.</p> Builder Design Pattern https://gustavopeiretti.com/build-design-pattern/ Sat, 19 Aug 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/build-design-pattern/ <p>The Builder design pattern allows you to create objects that are usually complex using another object that builds them step by step.</p> Composite Design Pattern https://gustavopeiretti.com/composite-design-pattern/ Sat, 19 Aug 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/composite-design-pattern/ <p>The Composite design pattern allows you to create objects from an interface by making them all similar and allowing them all to be treated in the same way.</p> Decorator Design Pattern https://gustavopeiretti.com/decorator-design-pattern/ Sat, 19 Aug 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/decorator-design-pattern/ <p>The Decorator pattern allows you to add new features to classes without modifying their structure.</p> Facade Design Pattern https://gustavopeiretti.com/facade-design-pattern/ Sat, 19 Aug 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/facade-design-pattern/ <p>The Facade design pattern simplifies the complexity of a system through a simpler interface.</p> <p>It improves access to our system by allowing other systems or subsystems to use a common access point that reduces complexity, minimizing interactions and dependencies.</p> Factory Design Pattern https://gustavopeiretti.com/factory-design-pattern/ Sat, 19 Aug 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/factory-design-pattern/ <p>The Factory design pattern is mainly used when we have a class or interface with many subclasses or implementations, and according to some input, we need to return one of these specific subclasses.</p> Observer Design Pattern https://gustavopeiretti.com/observer-design-pattern/ Sat, 19 Aug 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/observer-design-pattern/ <p>The Observer’s design pattern is used primarily when we are interested in any change of status being notified to anyone who needs to know about that change.</p> <p>In the observer design pattern, the object that looks at the state of another object is called “Observer” and the object that is “looking” those changes is called “Subject”.</p> Proxy Design Pattern https://gustavopeiretti.com/proxy-design-pattern/ Sat, 19 Aug 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/proxy-design-pattern/ <p>The Proxy design pattern is simply an intermediary that is designed over a class to add some additional functionality, without modifying the original class.</p> Singleton Design Pattern https://gustavopeiretti.com/singleton-design-pattern/ Sat, 19 Aug 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/singleton-design-pattern/ <p>This is one of the best-known patterns and is perhaps the first that comes to mind when you ask us about design patterns in Java.</p> <p>The goal is to have only one instance of a class involved and ensure that this happens every time this instance is needed.</p> Strategy Design Pattern https://gustavopeiretti.com/strategy-design-pattern/ Sat, 19 Aug 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/strategy-design-pattern/ <p>The Strategy design pattern helps to define different behaviors or functionalities that can be changed at runtime.</p> <p>In the Strategy pattern, we create different classes that represent strategies and that we can use, according to some variation or input.</p> Spring Boot with Maven Wrapper https://gustavopeiretti.com/spring-boot-with-maven-wrapper/ Tue, 11 Apr 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-with-maven-wrapper/ <p>Here we will cover the fundamental commands for building and running a Spring Boot application using Maven Wrapper.</p> Understanding Spring Boot @Autowired Annotation https://gustavopeiretti.com/spring-boot-autowired-annotation/ Tue, 07 Mar 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-autowired-annotation/ <p>In Spring Boot, @Autowired is an annotation that allows automatic dependency injection of beans. It is used to inject an instance of a class into another class.</p> Understanding Spring Boot @Configuration and @Bean Annotation https://gustavopeiretti.com/spring-boot-bean-annotation/ Mon, 06 Mar 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-bean-annotation/ <p>In Spring Boot, a @Bean is a method-level annotation that is used to declare a bean and register it with the Spring container.</p> Understanding Spring Boot @Value Annotation https://gustavopeiretti.com/spring-boot-value-annotation/ Fri, 17 Feb 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-value-annotation/ <p>The @Value annotation in Spring Boot is useful for injecting external values into your application.</p> Spring Boot Configuration Properties https://gustavopeiretti.com/spring-boot-configuration-properties/ Wed, 08 Feb 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-configuration-properties/ <p>@ConfigurationProperties is a feature in Spring Boot that allows you to bind external configurations to a Java class.</p> Spring Boot Profiles https://gustavopeiretti.com/spring-boot-profiles/ Mon, 23 Jan 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-profiles/ <p>Spring Boot profiles provide a way to customize the configuration and behavior of your application, based on the environment it is running in.</p> How to create a Unit Test for a RestController in Spring Boot https://gustavopeiretti.com/spring-boot-unit-test-rest-controller/ Wed, 11 Jan 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-unit-test-rest-controller/ <p>Spring Boot provides a convenient way to create unit and integration tests for your Spring Boot applications.</p> Integrating Swagger into Spring Boot https://gustavopeiretti.com/spring-boot-swagger-integration/ Tue, 03 Jan 2023 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-swagger-integration/ <p>In this post, we are going to integrate Swagger with our Spring Boot application.</p> How to perform loops in Java https://gustavopeiretti.com/how-to-perform-loops-java/ Tue, 22 Nov 2022 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/how-to-perform-loops-java/ <p>Loops are used to iterate items on a list or to traverse a certain part of the program several times as long as a condition is satisfied.</p> How to debug Spring Boot from the Gradle command line https://gustavopeiretti.com/spring-boot-gradle-debug-console/ Mon, 19 Sep 2022 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-gradle-debug-console/ <p>In this tutorial, we are going to see how to debug a Spring Boot Application with Gradle using the command line console.</p> Spring Boot with Gradle Wrapper https://gustavopeiretti.com/spring-boot-with-gradle-wrapper/ Fri, 02 Sep 2022 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-with-gradle-wrapper/ <p>Here we are going to learn the basic command to build and, run Spring Boot application with Gradle Wrapper</p> Spring Boot Init Database https://gustavopeiretti.com/spring-boot-database-initialization-sql-files/ Mon, 22 Aug 2022 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-database-initialization-sql-files/ <p>When we are developing Spring Boot applications it is a very common need to create tables and load into its data. Spring Boot provides an easy way to load initial SQL queries to insert registries in our database. Here we are going to understand how to initialize data with SQL files that Spring can load when it is starting.</p> H2 Spring Boot configuration https://gustavopeiretti.com/spring-boot-h2-database-config/ Thu, 18 Aug 2022 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-h2-database-config/ <p>We are going to understand how to configure Spring Boot in order to connect with an H2 Database.</p> Logging with Spring Boot https://gustavopeiretti.com/logging-with-spring-boot/ Thu, 11 Aug 2022 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/logging-with-spring-boot/ <p>Let’s see how to leave log records in Spring Boot.</p> How to send emails with Spring Boot https://gustavopeiretti.com/spring-boot-send-emails/ Mon, 25 Jul 2022 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-send-emails/ <p>In this post, we will understand how to send an email with Spring Boot.</p> How to connect SpringBoot with Databases https://gustavopeiretti.com/spring-boot-database-connection-config/ Thu, 23 Jun 2022 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-database-connection-config/ <p>Spring Boot allows you to connect a database simply with minimal configuration. Let’s see in this post how to connect to a database.</p> Spring Boot Entities https://gustavopeiretti.com/spring-boot-entities-initial-concepts/ Wed, 06 Apr 2022 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-entities-initial-concepts/ <p>An entity is the representation of information that we need in our application.</p> <p>This entity could be a user, a product, or any data that our application needs to keep persistently to retrieve when needed.</p> How to generate RSA keys with Java https://gustavopeiretti.com/rsa-keys-java/ Wed, 23 Mar 2022 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/rsa-keys-java/ <p>In Java, we can use native libraries to create RSA public and private keys. We will create, store, and load public and private keys in this example.</p> How to Encrypt and Decrypt using RSA keys with Java https://gustavopeiretti.com/rsa-encrypt-decrypt-java/ Tue, 22 Mar 2022 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/rsa-encrypt-decrypt-java/ <p>In this article we are going to use public and private RSA keys for encryption and decryption.</p> The Repository component in Spring Boot https://gustavopeiretti.com/spring-boot-repository-component/ Wed, 01 Dec 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-repository-component/ <p>In this post we will understand what a Repository Component is and how to create a CrudRepository in Spring Boot.</p> The Service component in Spring Boot https://gustavopeiretti.com/spring-boot-service-component/ Fri, 26 Nov 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-service-component/ <p>In this post we will understand what a Service component is and how it is created in Spring Boot.</p> How to create a Spring Boot Project with Intellij https://gustavopeiretti.com/create-project-spring-boot-intellij/ Wed, 24 Nov 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/create-project-spring-boot-intellij/ <p>To create a Spring Boot project, we can use the IntelliJ wizard.</p> How to create a Spring Boot Project with Spring Initilizr https://gustavopeiretti.com/create-project-spring-boot-initilizr/ Mon, 15 Nov 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/create-project-spring-boot-initilizr/ <p>To create a project in Spring Boot we can use ‘Spring Initializr’ utility.</p> The Properties file in Spring Boot https://gustavopeiretti.com/properties-file-spring-boot/ Wed, 10 Nov 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/properties-file-spring-boot/ <p>Spring Boot manages a properties file to carry general application settings.</p> The package structure in a Spring Boot application https://gustavopeiretti.com/package-structure-spring-boot/ Mon, 01 Nov 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/package-structure-spring-boot/ <p>In an application developed in Spring Boot we must be careful to order and structure the packages in a correct and understandable way. We will see the most standardized way to order packages in Spring Boot.</p> What are Components and Stereotypes in Spring Boot? https://gustavopeiretti.com/spring-boot-components-stereotypes/ Fri, 22 Oct 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-components-stereotypes/ <p>We will understand the concept of components within a Spring Boot application and the use of stereotypes.</p> How to create a Rest controller in Spring Boot https://gustavopeiretti.com/spring-boot-create-controller/ Thu, 21 Oct 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-create-controller/ <p>In this post, we will understand what a controller is and how to create a controller in Spring Boot.</p> How to create the main class in Spring Boot https://gustavopeiretti.com/spring-boot-create-main-class/ Wed, 13 Oct 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-create-main-class/ <p>To create a web application in Spring Boot we first need to determine the minimum libraries and then create the <em>main java</em> of the application to start the service. We will see here how to create the Spring Boot main to start it.</p> What is dependency injection in Spring https://gustavopeiretti.com/spring-injection-dependencies/ Tue, 12 Oct 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-injection-dependencies/ <p>Dependency injection is a design pattern that aims to take the responsibility of creating the instances of the classes that another object needs and supply it so that this class can use them.</p> What is Spring Boot https://gustavopeiretti.com/spring-boot-what-is/ Wed, 08 Sep 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-what-is/ <p>Spring Boot is a set of components that provide several tools to create services quickly and with minimal effort. Spring Boot uses preset configurations that save your time and avoid repetition in application development.<br> It also provides libraries for most of the needs in the creation of services, microservices and Rest applications.</p> Configuring Kafka and Spring Boot https://gustavopeiretti.com/configuring-kafka-and-springBoot/ Tue, 15 Jun 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/configuring-kafka-and-springBoot/ <p>Let’s see in this post how to implement and configure <a href="https://kafka.apache.org/">Apache Kafka</a> with SpringBoot. <br></p> <p>Spring provides a simple way to integrate with Kafka by providing a template to easily send messages and annotations to receive messages. in a simple way and annotations to receive the messages. We will use a docker image with Kafka to test its execution.</p> Change Intellij terminal to gitbash https://gustavopeiretti.com/change-intellij-terminal-gitbash/ Tue, 01 Jun 2021 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/change-intellij-terminal-gitbash/ <p>If you usually use the <em>gitbash</em> console in Windows and you prefer to use it also in your Intellij you can change the terminal easily.</p> Spring Boot - How to use WebClient https://gustavopeiretti.com/spring-boot-how-to-use-webclient/ Mon, 26 Oct 2020 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-how-to-use-webclient/ <p>We will examine here how to use Spring WebClient to make calls to a service by sending request.</p> Elasticsearch - How to use geolocation https://gustavopeiretti.com/elastic-search-geolocation/ Fri, 19 Jun 2020 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/elastic-search-geolocation/ <p>In this example, we are going to understand how to use ElasticSearch geolocation. We will add documents with geolocation using <em>geo_point</em> and then search for those documents using coordinates.</p> How to create an application with Spring Batch https://gustavopeiretti.com/how-to-create-an-application-with-spring-batch/ Fri, 03 Jan 2020 20:03:17 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/how-to-create-an-application-with-spring-batch/ <p>To configure a Spring Batch project we will start with the dependencies that we need to use Maven, then we will define the basic configuration and some simple aspects to connect to an embedded database.</p> Spring Boot with PostgreSQL and Docker Compose https://gustavopeiretti.com/spring-boot-with-postgresql-and-docker-compose/ Tue, 10 Dec 2019 14:02:48 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/spring-boot-with-postgresql-and-docker-compose/ <p>In this post you will learn how to create a Spring Boot application with a PostgreSQL database to run inside a Docker container.</p> How to create a microservice with Spring Boot and Docker https://gustavopeiretti.com/how-to-create-a-microservice-with-spring-boot-and-docker/ Tue, 12 Nov 2019 10:59:04 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/how-to-create-a-microservice-with-spring-boot-and-docker/ <p>We will learn how to run a Spring Boot microservice inside a Docker container</p> How to install Docker on Windows and create a Docker Hello World with Java https://gustavopeiretti.com/how-to-install-docker-on-windows-and-create-a-docker-hello-world-with-java/ Wed, 25 Sep 2019 20:37:24 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/how-to-install-docker-on-windows-and-create-a-docker-hello-world-with-java/ <p>We will see here how to install Docker on Windows and how to create a Java hello world in Docker .</p> How to change the time zone of a date https://gustavopeiretti.com/how-to-change-time-zone-date/ Fri, 29 Jun 2018 00:00:00 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/how-to-change-time-zone-date/ Let’s examine how to change the time zone of a date in java in different ways. How to change the timezone of a java.util.Date using SimpleDateFormat We must be clear that the Date class in Java does not have a time zone. java.util.Date represents the number of seconds from midnight January 1, 1970 to zero hours (UTC time). This means, java.util.Date will always return the time for the time zone that is by default defined for the system. How to install Maven on Windows https://gustavopeiretti.com/how-to-install-maven-on-windows/ Fri, 11 Sep 2015 12:54:11 +0000 hola@gustavopeiretti.com (Gustavo Peiretti) https://gustavopeiretti.com/how-to-install-maven-on-windows/ <p>Installing Maven on Windows requires few steps. Just download it in some folder, set it in the path and define the environment variable <em>M2_HOME</em></p> <p>Read this post with the steps to install Maven</p>