I know a way to see XML based configuration dependency graph (Spring Tool Suite) but that does not work for annotations such as #Autowired and application separated in maven modules. Is there any way we can see that at project level or module level?
The beans dependency graph feature in Spring IDE doesn't support non-XML-based Spring definitions.
There is a "live beans graph" feature that visualizes all the beans in a running Spring application. Maybe that helps in your case.
Related
Can I use springboot annotations like #Bean, #Component, #Autowired etc in plain java project with just using gradle dependencies?
To use spring frameworks annotations the project should be either spring boot or a project with all the required spring dependencies to support the above mentioned annotations.
No. Spring uses those annotations for the inversion of control. Without this framework they are useless in plain java.
I understand how SpringBoot saves time in other respects such as having an embedded server and starter dependencies, but how does SpringBoot reduce boiler plate code needed for an application?
Thanks
Spring Boot brings a ton of autoconfiguration classes, which create beans with default configurations, that would have been created by the developer themselves previously. An example would be beans for database access. You would have created a datasource, maybe a JdbcTemplate, connection pool etc. Now those beans are created with autoconfiguration (example: https://github.com/spring-projects/spring-boot/blob/master/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/DataSourceAutoConfiguration.java), and configuration can be customized through application.properties files.
Spring boot comes with starters and through maven you can search for the required dependency and add it to your project it supports rapid development and below are some key features of spring boot
Removes boilerplate code of application setup by having embedded web
server(Tomcat) and in memory db.
Auto configuration of application context.
Automatic servlet mappings.
Embedded database support(h2)
Automatic controller mapping
You can look at Spring Boot as an opinionated distribution of Spring. It comes with sane defaults and machanisms to hide the boilerplate while still making changes to those defaults possible.
When you use annotations #SpringBootApplication, Spring boot takes care of creating all the beans required for running WebServer and injecting it using its Dependency Injection feature.
#SpringBootApplication is alone equivalent to below three annotations.
#Configuration : You can define your own configuration class to register your beans in application context.
2.#EnableAutoConfiguration : Spring automatically creates beans available on your classs path using this feature.More details are available here.
#ComponentScan : Scans the current and base package where your application class lies.
It Creates ApplicationContext which contains all the necessary beans, ServletWebServerApplicationContext is one such bean created which takes care of initializing and running a WebServer by looking for ServletWebServerFactory bean(provides the webServer) within the ApplicationContext.
There is lot more going on behind the scene. Here is a video which explains it in details.
https://youtu.be/uCE3x4-GQ0k
https://docs.spring.io/spring-boot/docs/current/api/org/springframework/boot/web/servlet/context/ServletWebServerApplicationContext.html
I am a new user of Spring framework. I am facing some confusion in understanding the difference between core spring framework and spring boot. As far as I understand, Spring boot is a framework which performs the initial setup automatically (like Setting up Maven dependencies and downloading the jar files) and comes with an embedded Tomcat server which makes it ready to deploy in just one click., Whereas, Spring MVC requires manual setup. All the tutorials that I watched for core spring show bean configuration using bean factory which configures the beans using a .XML file. In Spring boot, this bean configuration file is absent. My question is, what is the use of this bean configuration file? I did not find any legitimate use of this file in making a REST service with spring. I didn't see any use of the Application Context, Bean Factory in creating web application. Can someone point out how can bean factory be used in Spring web apps? Is there any fundamental difference between core spring and spring boot other than the additional components?
The Spring application context is essentially the "pool" of beans (service objects, which include controllers, converters, data-access objects, and so on) and related information that define an application; I recommend the reference introduction. In theory, you can get complicated with the context setup and have hierarchical organization and such, but in most real-world cases you just have a single plain context.
Inside this context you need to install all of the beans that provide the logic for your application. There are several possible ways to do this, but the two main ways are by providing XML files with have directives like bean (define an individual bean) or component-scan (automatically search for classes with certain annotations, including #Controller) and by using Java classes annotated with #Configuration, which can use annotations and #Bean methods.
The XML style is generally older, and newer applications mostly use Java configuration, but both provide entries that are collected into the context, and you can use both simultaneously. However, in any application, you have to provide some way of getting the registration started, and you will typically have one "root" XML file or configuration class that then imports other XML files and/or configuration classes. In a legacy web.xml-based application, you specify this in your servlet configuration file.
Spring Boot is, as you said, essentially a collection of ready-to-go configuration classes along with a mechanism for automatically detecting configurations and activating them. Even this requires a configuration root, though! This is the #EnableAutoConfiguration instruction, frequently used through its composite #SpringBootApplication. The application context and configuration mechanisms work normally once Boot finds them and pulls them in. Spring knows where to get started because you give it an explicit instruction to build a context starting with that entry point, usually with SpringApplication.run(MyApplication.class, args).
The embedded-server configuration just happens to be a particular set of configuration that is really useful and comes with one of the Boot starter packages. There's nothing there that you couldn't do in a non-Boot application.
I want to develop my springboot configuration module.
For example, I want to the behaviors of serialization and deserializion consistent in the Spring ConverterSPI and JsonHttpMessageConverter/XmlHttpMessageConverter.
So,i try to register all converters in Spring ConverterSPI to global configuration JsonHttpMessageConverter/XmlHttpMessageConverter provides.
And decide whether to open by configuration.
For this spring-boot configuration module, I don't want to rely on the spring-boot version.
Otherwise, the actual spring-boot project needs to exclusion the transitive dependencies spring boot when introducing this module.
How to achieve this goal?
What's the best method to initiate a new Spring Project ?
Initiating Spring project is a lot of pain with various xml and db configuration.
Is there an "official" repository with complete sample project, as MVC with db access and so ?
Spring Boot may also be the solution, but some point still not clear to me :
How to add external components (such as Quartz) without creating some xml config ? (No such xml in Boot apparently)
Is a Spring Boot builded app is production-proof ?
As writen in the comments http://start.spring.io/ is the best way to start Spring boot project(STS has integration for it).
If you want to use something that is not supported by Spring Boot you can init spring beans the same way you do it in xml, just use java configuration. See this for example: http://www.tutorialspoint.com/spring/spring_java_based_configuration.htm
Also useing xml is still available. You can add #ImportResource on your Configuration class
#EnableAutoConfiguration
#Configuration
#ImportResource({"classpath*:applicationContext.xml"})