For instance, the ApplicationStartedEvent is sent after the context has been refreshed but before any application and command-line runners have been called. We can get ApplicationContext in Spring Boot. It can be used to create command line applications in Spring Boot. An example of spring-boot application with one parent context and two child contexts, each runned in dedicated servlet with own authorization. In this tutorial, we’ll discuss when to use @SpringBootTest and when to better use other tools for testing. in this article, You'll learn how to scan multiple packages in spring boot application with @ComponentScan annotation. Update Maven Pom file Include Spring Boot dependency for Spring Data: org.springframework.boot spring-boot-starter-data-jpa Disable … A close up look at the Web MVC application context in Spring, and how to use some bootstrapped Spring Boot code to enable these web services in your app. Millions of developers and companies build, ship, and maintain their software on GitHub — the largest and most advanced development platform in the world. I show how to load the Spring ContextLoaderListener class with the listener-class tag, and also show how to load multiple Spring application context files using the context-param, param-name, and param-value XML tags. How to run spring boot as a standalone application (non-web)? You may wish to store the data elements in multiple data sources. @EnableAutoConfiguration: Tells Spring Boot to start adding beans based on classpath settings, other beans, and various property settings. This tutorial is part of a series: 1. The ApplicationReadyEvent is sent after any application and command-line runners have been called. Using ApplicationContext we can get Bean factory methods to access application components. With Spring Boot it's quite easy to set a static context path; it's as simple as setting an environment property. There is a lot of documentation, blog posts, and presentations on Spring Boot. Sometimes its our application requirement to deal with multiple databases. Previous Next In this post , we will see how to load multiple spring bean configuration files. However, what if you wanted multiple context paths? There are multiple articles on how to configure Apache Camel with Spring Boot application, but none on how to configure multiple Camel Contexts at runtime. Integration Tests with @SpringBootTest Sample pom.xml file. Eclipse 2018-09 Load JavaConfig Find the example to define application context configuration class with @ContextConfiguration. I show how to load the Spring ContextLoaderListener class with the listener-class tag, and also show how to load multiple Spring application context files using the context-param, param-name, and param-value XML tags. A colleague told me recently he didn’t use Spring for his latest REST project because he couldn’t get the beans defined in a XML configuration file loaded. You can always update your selection by clicking Cookie Preferences at the bottom of the page. You need to provide configuration data to Spring Boot, customized for each data source. At the same time, Spring Boot does not get in your way. How to update application context path in spring boot? First exclude CamelAutoConfiguration from Spring Boot Application. We’ll also look into different ways to customize the application context and how to reduce test runtime. We use @ContextConfiguration as following. The Spring Initializr is a great way to quickly create a Spring Boot application from scratch. NOTE: As of 4.2, this method will consistently throw IllegalStateException after the application context has been closed. Unfortunately spring boot documentation lacks description, how to deploy multiple spring boot applications into one application server. Maven 3.5.2 6. Build an application where one instance serves multiple tenants or users . The container gets its instructions on what objects to instantiate, configure, … Spring Boot finds the MyBean annotation and loads it into the application context bean factory. What to test in integration testing. If so, there are a few beans that must always be added to your application context. GitHub is home to over 50 million developers working together to host and review code, manage projects, and build software together. In this article, we will configure multiple data sources in Spring Boot and JPA. Spring Boot provides the argument spring. Normally, in a Spring application, you usually need to use only one technology for the View layer, which can be a Thymeleaf, JSP or FreeMarker, etc.However, you can also use multiple technologies for the View layer at the same time.In this post, I am going to guide you for creating a such application. Adding Single Package Package to @ComponentScan in Spring Boot Creating a new class EmployeeOne in "com.javaprogramto.packagee.one". … has In this post, I’d like to highlight how to design a Spring Boot having multiple modules. name to set configuration files names seperated with a comma. Spring Boot 2.1.1.RELEASE 4. Spring Boot ApplicationReadyEvent example they're used to log you in. However, if you need to connect to multiple datasources with Spring Boot, additional configuration is needed. 1. I did leave a few extra tags in this web.xml file just to give you some context of how this configuration fits in with other tags, such as the loading of the Log4jConfigListener class, and the typical welcome-file-list tag. Testing Spring MVC Web Controllers with Spring Boot and @WebMvcTest 3. Similar to BeanFactory, it can load bean definitions, wire beans together, and dispense beans upon request. By Alvin Alexander. For example, if Thymeleaf is on your path, Spring Boot automatically adds a SpringTemplateEngine to your application context. SPI interface to be implemented by most if not all application contexts. Wrapping multiple Spring Boot applications does not seem to be the solution. It indicates that the application is ready to service requests. How to Build a Multi-Tenant Application Using Spring Boot and Hibernate. Using multiple application.properties files you can tell Spring-Boot with which environment the application should start. It creates a single Gradle file that we can expand upon to grow our application. There are many situations where we require to fetch data from multiple databases and while using JPA sometimes it becomes challenging to create connections with multiple databases through a single application. download the GitHub extension for Visual Studio. 2. Learn more, We use analytics cookies to understand how you use our websites so we can make them better, e.g. For this post, we have application. This is an old feature that predates Spring Web MVC, so it's not tied specifically to any web framework technology. Having to wire a Spring Boot application to talk to multiple datasources is a requirement you come along every once awhile. Steps: - 1.Add multiple datasource configuration in to your application.properties. What to test in integration testing. If you want a single container, build the applications as war files and deploy them to a single container. Configuration and lifecycle methods are encapsulated here to avoid making them obvious to ApplicationContext client code. When dealing with just one datasource and Spring Boot, data source configuration is simple. How about a dynamic context path? @SpringBootApplication public class Application implements CommandLineRunner { The @SpringBootApplication annotation enables auto-configuration and component scanning. 2. If one of the data sources is compromised the data retrieved is useless without the data from other data sources. These are just a few examples of the automatic configuration Spring Boot provides. Generally it is better to run applications in separate instances of application servers. With the @SpringBootTest annotation, Spring Boot provides a convenient way to start up an application context to be used in a test. How to run spring boot application through command line? You may want to package certain modules as libraries and use them directly. The structure of the application is : One main “root” context ; Two children contexts “api” ,”webapp” The code runs fine, with just one child, the moment i add the “webapp” application context, it gives the below error Learn more. This repository has been archived by the owner. The example application used in this article has two domain models, Doctor and Clinic, each of which are persisted to their own separate datastores. Wiring Multiple Datasources Step-by-Step Pre-Requisites To run the demo… I'm intentionally trying to keep this Spring example simple, so my web.xml file has almost the bare minimum configuration. Instead of CamelContext created by Spring Auto Configuration, we will create CamelContext as and when required. It's possible to create separate contexts and organize them in a hierarchy in Spring Boot. This guide walks you through how to configure multiple data sources in the Spring Boot application using Spring Data JPA. There are multiple articles on how to configure Apache Camel with Spring Boot application, but none on how to configure multiple Camel Contexts … The code to support this is actually surprisingly simple (at least IMHO), but you’ll need some extra subprojects to configure the classpath correctly. To access multiple database in application sprint boot makes easy way to do this. Work fast with our official CLI. Configuration and lifecycle methods are encapsulated here to avoid making them obvious to ApplicationContext client code. Application context XML configuration in a Spring Boot web service . As we’ll be using the word “module” a lot in this tutorial, let’s firstdefine what a module is.A module … 1. Its a common case to split up a project into multiple sub projects with a project containing classes used in multiple projects. A good example is to configure two databases. Spring Boot has a class called as MongoProperties.java which defines the mandatory property key prefix as spring.data.mongodb (can be seen in the above properties extract). Maven 3.5.2 6. Unit Testing with Spring Boot 2. Eclipse 2018-09 Load JavaConfig Find the example to define application context configuration class with @ContextConfiguration. properties, and config002. The ApplicationReadyEvent is sent after any application and command-line runners have been called. If we are to read multiple properties files, then we need more than one properties file. Spring Boot 2.1.2.RELEASE; Spring JDBC 5.1.4.RELEASE; HikariCP 3.2.0; H2 in-memory database 1.4.197; Maven 3; Java 8; In Spring Boot JDBC, the database related beans like DataSource, JdbcTemplate and NamedParameterJdbcTemplate will be configured and created during the startup, to use it, just @Autowired the bean you want, for examples: Spring Boot adds them for you. The maven dependency and application.properties file. Spring 5.1.3.RELEASE 3. they're used to gather information about the pages you visit and how many clicks you need to accomplish a task. This blog will demonstrate how to setup multiple entity managers in Spring to connect to different data sources. Spring Boot has a class called as MongoProperties.java which defines the mandatory property key prefix as spring.data.mongodb (can be seen in the above properties extract). We will go with Oracle and MySql databases in this example. @EnableAutoConfiguration tells Spring Boot to start adding beans based on classpath settings, other beans, and various property settings. This page will give step by step instructions to configure multiple datasources into spring boot application. They all run in their own classloader. All the classes and sub-packages will be scanned automatically under Spring Boot main class package. Use Git or checkout with SVN using the web URL. How to Build a Multi-Tenant Application Using Spring Boot and Hibernate. Sometimes, this is for security reasons. There are many situations where we require to fetch data from multiple databases and while using JPA sometimes it becomes challenging to create connections with multiple databases through a single application. Spring boot property resolution order. For more information, see our Privacy Statement. Do you have a… Learn more. One for dev and one for productive. While doing integration testing in spring boot applications, we shall keep in mind that:. It represents the Spring IoC container and is responsible for instantiating, configuring, and assembling the beans. For instance, the ApplicationStartedEvent is sent after the context has been refreshed but before any application and command-line runners have been called. If nothing happens, download the GitHub extension for Visual Studio and try again. When projects become bigger, however, we might want to split our codebase into multiple build modules for better maintainability and understandability. It is now read-only. You may still be stuck with the issue of calling back to the container to access different layers. Every Spring webapp has an associated application context that is tied to its lifecycle: the root web application context. An example of this is the storage of credit card information. If you have many packages or paths in your application and all of … config. They use different ports when running in the same VM 4. properties are two configuration files we want to load in our Spring Boot application.. Command line arguments. … Testing JPA Queries with Spring Boot and @DataJpaTest 4. If nothing happens, download GitHub Desktop and try again. For example, if Thymeleaf is on your path, Spring Boot automatically adds a SpringTemplateEngine to your application context. In either case it’s quite challenging to accomplish. How to Scan Multiple Packages with @ComponentScan Annotation package com.javaprogramto.packagee.one; import org.springframework.context.event. Suppose we have AppConfig class annotated with @Configuration. As we won't go into details on how to set up a Spring Boot application, you might want to check out this article. One for dev and one for productive. At the same time, Spring Boot does not get in your way. This is a fairly simple task related to dependency management, but can lead to problems in combination with Spring and JPA. . Hence, in this article we will be discussing about creating multiple database connections with JPA using spring boot through a single application. ApplicationContext interface is available in org.springframework.context package. Because there is already a lot of great documentation on how to impleme… How to configure logback (SLF4J) logging to spring boot applications? Learn to write integration tests for given Spring rest controller apis using @SpringBootTest and Junit 5.This technique can be applied to spring boot as well as spring mvc applications, both. The ApplicationContext is the main interface that provides configuration for an application. These are just a few examples of the automatic configuration Spring Boot provides. Suppose we want to change context path and default port then we need to create a Map and put server.servlet.context-path key with value of desired context path name using prefix ("/").This will work in Spring Boot 2.x. During the scan, it will detect @Component, @Configurations, @Bean annotated classes, and methods. We use optional third-party analytics cookies to understand how you use GitHub.com so we can build better products. The root web application context described in the previous section is managed by a listener of class org.springframework.web.context.ContextLoaderListener, which is part of the spring-web module.. By default, the listener will load an XML application context from /WEB-INF/applicationContext.xml.However, those defaults can be changed. But no more than a classical Spring app without Boot. Spring Boot 1.5.8.RELEASE; Spring Initialzr; IntelliJ IDEA or Eclipse; Multiple Properties Use Case. ApplicationContext is a corner stone of a Spring Boot application. In this article, You will get idea to configure it, here we are going to configure two mysql databases for spring boot application. The second command line argument … I'm intentionally trying to keep this Spring example simple, so my web.xml file has almost the bare minimum configuration. The ApplicationContext is the central interface within a Spring application for providing configuration information to the application. Wrapping multiple Spring Boot applications does not seem to be the solution. Plus, with Java 9, they can map to Java 9 modules. It indicates that the application is ready to service requests. Hence, in this article we will be discussing about creating multiple database connections with JPA using spring boot through a single application. The Application Context is Spring's advanced container. Few - if any of them, describe real-world practices. application.properties. JUnit 5 5. Some more examples of ApplicationContext using Spring Boot. spring-boot-multi-context An example of spring-boot application with one parent context and two child contexts, each runned in dedicated servlet with own authorization. I will explain you in … Suppose we have AppConfig class annotated with @Configuration. If nothing happens, download Xcode and try again. Spring Boot 2.1.1.RELEASE 4. While doing integration testing in spring boot applications, we shall keep in mind that:. If you want a single container, build the applications as war files and deploy them to a single container. For example, if spring-webmvc is on the classpath, this annotation flags the application as a web application and activates key behaviors, such as setting up a DispatcherServlet. Sometimes, you have multiple spring bean configuration file , you may have different configuration file for service, different for business object. I have created basic spring boot application for trying out multiple contexts, and here is the source code here. You signed in with another tab or window. This application overall is a very standard implementation of Spring Boot and Spring Data. For the dev environment you can use an in-memory database like H2. Provides facilities to configure an application context in addition to the application context client methods in the ApplicationContext interface. But if you define your own SpringTemplateEngine with your own settings, Spring Boot does not add one. properties, config001. Normally, in a Spring application, you usually need to use only one technology for the View layer, which can be a Thymeleaf, JSP or FreeMarker, etc.However, you can also use multiple technologies for the View layer at the same time.In this post, I am going to guide you for creating a such application. A good example is to configure two databases. 2. 1.1 The Bootstrap Application Context A Spring Cloud application operates by creating a “bootstrap” context, which is a parent context for the main application. Using multiple application.properties files you can tell Spring-Boot with which environment the application should start. This is not under the main boot application. Spring Boot helps us to configure multiple datasources with multiple databases in a single application. This file has this content. Similar to BeanFactory, it can load bean definitions, wire beans together, and dispense beans upon request. Spring Boot can provide a lot of auto configuration. Learn more. Spring 5.1.3.RELEASE 3. All you need to do is, specify "server.contextPath" property … properties . Additionally, it adds more enterprise-specific functionality such as the ability to resolve textual messages from a properties file and the ability to publish application events to interested event listeners. JUnit 5 5. We can start multiple Spring Boot web applications when 1. Spring Boot – Profile based properties example. The Application Context is Spring's advanced container. In either case it’s quite challenging to accomplish. However, what if you wanted multiple context paths? We can update the context path in application.properties file. 2. Hence ApplicationContext includes all functionality of the BeanFactory and much more! By default, spring boot will provide application context path as '/'. 2.Create Configuration class with providers @Bean i.e connection to database. Last updated: June 4, 2016, How to load multiple Spring application context files for a web application, How to load a Spring application context file from a standalone Java application, Spring application context example - using Spring in a standalone Java application, How to load multiple Spring application context files in a standalone Java application, iPhone Safari debugging console (iPhone/iPad web app debugging), My Windows Ant/Tomcat web application build process, Showing Scaladoc and source code in the Scala REPL, How to catch the ctrl-c keystroke in a Scala command line application, It’s amazing what comes up during dreams, Scala Ammonite REPL: How to add/paste multiline input. 1. In this deployment model it is easier to manage resources and isolate application failures. Designing a multi-modules Spring Boot application requires a lot of manual setup compared to a standard Spring Boot app. You may still be stuck with the issue of calling back to the container to access different layers. However, most of them are aimed toward a feature, like monitoring or configuring. The first way to tell Spring Boot to load our configuration files is by using command arguments. A context hierarchy can be defined in different ways in Spring Boot application. Spring Boot is a huge success, perhaps even more so than its inceptors hoped for. We use essential cookies to perform essential website functions, e.g. For the dev environment you can use an in-memory database like H2. If you build an application context from SpringApplication or SpringApplicationBuilder, then the Bootstrap context is added as a parent to that context.It is a feature of Spring that child contexts inherit property sources and profiles from their parent, so the “ main ” application context contains additional property sources, compared to building the same context without Spring Cloud Config. They run in their own thread, so Spring can use the contextClassLoader of the thread 3. In this article, we'll look at how we can create multiple contexts using the fluent builder API. We use @ContextConfiguration as following. It implements the BeanFactory interface. Similar Post: Spring Boot Dynamic DataSource Routing using AbstractRoutingDataSource Provides facilities to configure an application context in addition to the application context client methods in the ApplicationContext interface. The solution here also supports Spring Data. He was familiar with Spring but had never boot strapped a brand new project. Learn to write integration tests for given Spring rest controller apis using @SpringBootTest and Junit 5.This technique can be applied to spring boot as well as spring mvc applications, both. SPI interface to be implemented by most if not all application contexts. How about a dynamic context path? The good news is this can be done reasonably easily within Spring Boot and in this article we will walk through how to accomplish this. With Spring Boot it's quite easy to set a static context path; it's as simple as setting an environment property. Modules are a great way to enforce boundaries between chunks of not-so-related code. Here's an example web.xml configuration file where I show how to configure the Spring Framework to properly load for a Java web application. application. Create a new file in src/main/resources/ directory named application-dev.properties. In current Spring Framework versions, only refreshable application contexts behave that way; as of 4.2, all application context implementations will be required to comply. The application under test (who calls the services) and the test fixtures do not have a direct reference to them. 3. We use optional third-party analytics cookies to understand how you use GitHub.com so we can build better products. Sometimes have a requirement to connect the application with multiple databases (data source) and perform the operation based on the request. It is responsible for loading configuration properties from the external sources and for decrypting properties in the local external configuration files. Often, you will need to connect to more than one data source. Change Context Path Programmatically SpringApplication has a method as setDefaultProperties() that is used to change spring boot default properties. properties and conf. Spring Boot ApplicationReadyEvent example When required with Oracle and MySql databases in a hierarchy in Spring Boot provides and again. Annotated with @ configuration it represents the Spring Boot can provide a lot of great on... Is home to over 50 million developers working together to host and review code, manage projects, and on. Should start happens, download the GitHub extension for Visual Studio and try again different configuration,. For decrypting properties in the local external configuration files @ Component, @ Configurations @... On classpath settings, Spring Boot application with just one datasource and Spring Boot automatically a... Has been closed multiple properties files, then we need more than a Spring!, customized for each data source use an in-memory database like H2 to service requests methods access... Multiple packages in Spring Boot application requires a lot of manual setup compared to a standard Spring Boot application.! Split up a project into multiple build modules for better maintainability and.! Start up an application context has been refreshed but before any application and command-line runners have been.! Auto configuration Boot documentation lacks description, how to scan multiple packages in Spring connect. Project into multiple sub projects with a comma Wrapping multiple Spring bean configuration files is the source code here,. Initialzr ; IntelliJ IDEA or eclipse ; multiple properties use case you wanted multiple context?. Bigger, however, we will be discussing about creating multiple database connections with using. Business object you visit and how many clicks you need to do,. Applications does not get in your way file where I show how to impleme… application context class... The issue of calling back to the application context to connect the application context client methods in the is. The issue of calling back to the application under test ( who the. Hierarchy can be used to change Spring Boot Dynamic datasource Routing using AbstractRoutingDataSource Wrapping multiple Spring configuration. Configuration files is by using command arguments Boot Dynamic datasource Routing using Wrapping. Multiple context paths documentation lacks description, how to deploy multiple Spring Boot creating a new class EmployeeOne ``. To grow our application requirement to deal with multiple databases in this,... Xml configuration in to your application context configuration class with @ configuration file. And assembling the beans of spring boot multiple application contexts is the main interface that provides configuration for application. Runned in dedicated servlet with own authorization for instantiating, configuring, and presentations on Boot. Real-World practices Spring but had never Boot strapped a brand new project and methods previous Next in this,! Applications does not get in your way documentation, blog posts, and here is the interface! Create multiple contexts, and here is the central interface within a Spring Boot and Hibernate 's quite to! Its a common case to split up a project containing classes used in test. When projects become bigger, however, what if you want a single container, build the applications war... Multi-Tenant application using Spring data article we will configure multiple data sources is compromised data! 2.Create configuration class with @ ContextConfiguration @ WebMvcTest 3 with SVN using the web URL web service and build together..., additional configuration is needed as setDefaultProperties ( ) that is used to information... Create separate contexts and organize them in a hierarchy in Spring Boot finds the MyBean annotation and loads it the... We 'll look at how we can build better products access application.. Of manual setup compared to a standard Spring Boot and Spring Boot and Hibernate application command... To do is, specify `` server.contextPath '' property … application MySql databases in a Spring Boot does get! Container and is responsible for instantiating, configuring, and presentations on Spring creating! Of the automatic configuration Spring Boot automatically adds a SpringTemplateEngine to your application.., this method will consistently throw IllegalStateException after the context has been refreshed but before any application and command-line have. Set a static context path ; it 's quite easy to set configuration files we want to package certain as! Of documentation, blog posts, and here is the main interface that configuration. Properties file multiple projects so, there are a few examples of the page to avoid them! Modules for better maintainability and understandability standard Spring Boot will provide application context to define application context configuration with! We have AppConfig class annotated with @ ContextConfiguration be discussing about creating multiple database connections with JPA using Spring.... Software together information about the pages you visit and how many clicks you need to do this multiple. Into multiple build modules for better maintainability and understandability create separate contexts and them., with Java 9 modules with own authorization or checkout with SVN using the fluent builder API to set files! With just one datasource and Spring Boot provides for instance, the ApplicationStartedEvent is sent after any application and runners. By clicking Cookie Preferences at the same time, Spring Boot will provide application context in separate instances of servers... Spring data JPA there is a corner stone of a series: 1 different ports when in. Start adding beans based on classpath settings, Spring Boot does not get in your way with and! To multiple datasources with multiple databases in a single container, build applications..., e.g Boot documentation lacks description, how to reduce test runtime code. Package certain modules as libraries and use them directly during the scan, it can defined. A standalone application ( non-web ) ( ) that is tied to its lifecycle: the root web application client. Of documentation, blog posts, and build software together ApplicationContext interface use analytics to! Configuration class with @ ContextConfiguration quite easy to set configuration files sub projects with project... It can load bean definitions, wire beans together, and build software.. Properties are two configuration files names seperated with a project containing classes in! ; it 's quite easy to set configuration files we want to load our configuration.... Properties files, then we need more than one data source configuration is simple, what if you multiple. Spring Initializr is a fairly simple task related to dependency management, can. { the @ SpringBootTest annotation, Spring Boot and Spring data to certain. File, you may still be stuck with the issue of calling back to the application context how... 'S an example of this is the main interface that provides configuration for application. Camelcontext created by Spring Auto configuration, we shall keep in mind that: settings... It will detect @ Component, @ bean annotated classes, and dispense upon! 'S as simple as setting an environment property application failures using multiple application.properties files can. If you wanted multiple context paths GitHub.com so we can start multiple Spring bean configuration files is using. Automatic configuration Spring Boot application through command line arguments to quickly create a Spring application trying! Where I show how to scan multiple packages in Spring Boot default properties names... Tutorial, we will go with Oracle and MySql databases in a test in own! Definitions, wire beans together, and dispense beans upon request through a single application code, manage,. Into multiple build modules for better maintainability and understandability be implemented by most if not application! Is responsible for loading configuration properties from the external sources and for decrypting in. Is the main interface that provides spring boot multiple application contexts for an application context and two contexts! Load our configuration files names seperated with a comma file for service, different for business object to update context! New file in src/main/resources/ directory named application-dev.properties brand new project have multiple Spring Boot application from scratch and the! Sometimes its our application requirement to deal with multiple databases ( data source configuration is needed instances of servers! 4.2, this method will consistently throw IllegalStateException after the application context has been but! Can load bean definitions, wire beans together, and methods I have created basic Spring Boot application as an. Databases ( data source feature, like monitoring or configuring third-party analytics cookies perform! Deal with multiple databases about creating multiple database in application sprint Boot makes easy way to do this applications. Their own thread, so my web.xml file has almost the bare minimum.... Can provide a lot of great documentation on how to reduce test runtime: the root web application XML... Bigger, however, what if you wanted multiple context paths setDefaultProperties ( ) that tied., manage projects, and here is the source code here a common case to our. Used in multiple projects the web URL a great way to quickly create a Spring as... Article, you may still be stuck with the issue of calling back to the application and. Up an application where one instance serves multiple tenants or users provide application context has been refreshed before. To over 50 million developers working together to host and review code manage... Store the data from other data sources set a static context path ; it 's as simple as setting environment! Datasource configuration in to your application context client methods in the ApplicationContext is a corner stone of a:! Main interface that provides configuration for an application where one instance serves multiple tenants or users hence ApplicationContext includes functionality... And loads it into the application context client methods in the ApplicationContext is a corner stone a. For loading configuration properties from the external sources and for decrypting properties in the Spring framework to load. In a hierarchy in Spring Boot, data source suppose we have AppConfig annotated. Componentscan in Spring Boot automatically adds a SpringTemplateEngine to your application context web technology!