In spring boot I want define #PropertySource("classpath:config.properties") globally for all controller
how to achive this?
add this annotation
#PropertySource("classpath:config.properties")
Over your #SpringBootApplication class (main class)
Related
Well i am a newbie in spring boot. I was working on a project where I needed to #Autowired my Entity in a controller class. But I ended up with error:
Field repository in abc required a bean of type 'xyz' that could not be found.
But it solved after adding #Component in Entity class.
So my questions are:
Why Spring boot was not scanning my Entity class as it was under #SpringBootApplication declaration?
When and where we should use #Component annotation in our application?
Use #Component to flag your Pojo as Spring Bean, so that you inject it into other beans with #Autowired
Use #Entity to flag your Pojo as JPA or Spring Data managed bean to read or write it to a database
In Spring Boot, is there a way to prevent Auto Configuration of all modules? Basically am looking for something like #DisableAutoConfiguration instead of excluding specific configurations with class names.
Auto-configuration is enabled by the #EnableAutoConfiguration annotation. If you don't want to use auto-configuration, then omit this annotation. Note that #SpringBootApplication is itself annotated with #EnableAutoConfiguration so you'll have to avoid using it too. Typically, this would leave your main application class annotated with #ComponentScan and #Configuration.
According to the reference using-boot-configuration-classes, I used #ComponentScan on the Application class and use the #Configuration on my config class, in my config class, I want to inject beans defined in other config class by using #Autowired annotation, but when I run the application, I got null for these fields, I tried to use import on the application and remove the #Configuration from config class, everything works fine.
Is it a bug of spring boot or I am misunderstanding about the usage of #Configuration annotation?
Are you trying to autowire other configuration classes into Application class?
Use a fresh method along with #PostConstruct to make it call automatically after Spring creates an instance of Application class.
How does SimpleCORSFilter work in this example?
Enabling Cross Origin Requests for a RESTful Web Service.
I only see a declaration of SimpleCORSFilter class but no instance. I tried ctrl+f to search the example page but can't find anywhere this class be instantiated.
How does it work?
I am new to Spring and Java.
So more detail more helpful. Thx.
A main point of Spring is a mechanism called dependency injection. Spring allows you to mark your classes, instance variables and so on with special annotations. Spring will look for those annotations and configure your application according to them.
In your example you annotate your filter with #Component:
#Component
public class SimpleCORSFilter implements Filter
And you annotate your Application class with #SpringBootApplication:
#SpringBootApplication
public class Application
The second annotation (#SpringBootApplication) tells Spring to search through your project for #Component annotations. As you annotated your filter with this, Spring will find your filter and instantiate it automatically. That's how your filter will be created and put to the right place.
Say i am using #Scheduled annotation on a function. But i want that annotation to take effect only if some property is defined in properties file. How do we configure that scenario?
Use case: Same app deployed on multiple servers but #Scheduled should be active only on one server.
My Idea:
Use an extra bean (MyScheduler), that contains nothing more than a method annotated with #Schedule. This Method "forward" the invocation to your real Service.
Then annotate the MyScheduler class with #Component and #Profile
The use your properties file to enable or disable this profile
Sketch:
#Component
#Profile("onTHEserver")
public class MyScheduler{
#Autowire
private RealService realService;
#Schedule(cron="1****") {
realService.doSomething();
}
}
#See: Spring 3.1 M1: Introducing #Profile
#See: #Profile Java Doc