Can we read the property values from the DB instead of setting up it on application.properties ? or even can we update the property value from code if a default value is set up in the application.properties file
You're probably looking for the Spring Cloud Config Server.
The spring context is initialized with the values from application.properties to which your database config belongs as well. You would need to establish the database connection prior to constructing the whole application context and then reading properties from the database. This can probably be achieved by modifiying how Spring works, but I'd rather recommend using a means officially supported by Spring.
Related
Currently i am working on a REST based project in Spring Boot.
I have added the api url in 'application.properties' file.
i.e.
application.properties
api-base-url=http://localhost:8080/RestServices/v1
And also this 'api-base-url' value access from java.
In some situations i need to change the 'api-base-url' dynamically.
I have change 'api-base-url' value dynamically & working fine.
But my problem is that
when wildfly restart then the configuration will be reset to default.
i.e
This is my default value
api-base-url=http://localhost:8080/RestServices/v1
dynamically change to
api-base-url=http://10.34.2.3:8080/RestServices/v1
when wildfly restart then the configuration will be reset to default.
i.e.
api-base-url=http://localhost:8080/RestServices/v1
Have any solution for this?
You might want to consider using a cloud config server to host your config. Two examples are Spring Cloud Config and Consul.
These servers will host your application's configuration and your spring boot application will make a call out to the config server on start up to get it's config.
spring-boot-actuator exposes the endpoint /refresh which forces the application to refresh it's configuration. In this case, it will call out to the config server to get the latest version.
This way you can change the config hosted in the config server then hit the /refresh endpoint and the changes will be picked up by your application.
As #moilejter suggests, one possible way is to persist in database table and at start time you simply read from that table instead of application.properties file. Your application.properties files can hold information necessary for database connection.
You would also need a JMX method or a REST API to trigger in your application that the url has changed and which inturn, would simply read from same table. This way you would be safe even if app restarts and you won't lose the override.
You can use BeanFactoryPostProcessor coupled with Environment bean to leverage spring placeholder concept.
#user2214646
Use spring expression language
I need to change "max_allowed_packet" property for mySQL data base from SPRING property file (application.yml). I found some topics about that, like this.
They proposed to use mySQL command line:
$>mysql --max_allowed_packet={some_value}
But maybe someone know new solution for this task? It would be great to have this ability.
You cannot change --max_allowed_packet property from spring application.yml file, because this is a mysql server property. Therefore you should set this property when you start the mysql server.
You could add it in my.cnf, check this answer
Currently, we store our application's environment properties in a .properties file in the WEB-INF. We want to move them to a database table. But we still want to specify the jndi name, and when running in our test environment locally, we want to be able to override certain properties just for our workspace for test and development.
Apache commons' DatabaseConfigurator seemed nice, but wouldn't play nice with the jndi name being defined as a property in the file. Nothing I did to ask it to look at the property file first worked.
I decided to subclass apache commons' AbstractConfiguration to try to create a single configurator that would check the file and database as I wished, but again, it didn't really work. Spring wants that jndi name absolutely first, probably because the data source has to be passed into the configurator as a parameter.
How can I get what I am after here? Mostly properties in the database, but those that are in the file override them. And jndi name for the datasource should not have to be hardcoded in the spring config.
Why don't you write a ApplicationContext listener that will read the configuration from your DB and inject them in the JNDI? Then you can override the configuration in the JNDI with a context.xml file that will be placed in the src/local/webapp/META-INF/.
This is how we get this working in our webapp.
I have a spring boot application and I want to use both a yml file for my application properties and also a plain application-${profile}.properties file set to configure my application.
So my question is can this be done and if so, how do you configure spring boot to look for both the yml file and the properties and merge them into one set per environment?
As to why I want/need to use both, it is because I like the flexibility and ease of use of yml files but an internal component (for encryption) requires using the properties file set.
I did see this point being made YAML files can’t be loaded via the #PropertySource annotation
but nothing stating whether both can be used together.
Please provide detailed configuration (XML or Java config) on how to get this working.
TIA,
Scott
I can answer my own question, as it just works as you would expect. The application.yml file and the appropriate application-${profile}.properties both get loaded and merged into the environment. Spring boot just makes this work naturally.
Yes You can use both at same time in same project.
When you use both YML and properties at same time, say for example
application.yml and application.properties at same time in same
project, first application.yml will be loaded, later
application.properties will be loaded.
Important point to be noted is that if application.yml and
application.properties have same keys for example in
application.yml has spring.app.name = testYML and
application.properties has spring.app.name = testProperties at same
time in same project, then application.yml value will be overwritten
by application.properties value since it is loading at last.
And the value in spring.app.name = testProperties.
Yes, you can run both without doing any configuration.
In Spring Boot, it picks .properties or .yaml files in the following sequences :
application-{profile}.{properties|yml}
application.{properties|yml}
I am programming service for getting data from database and providing them via REST service. It uses spring mvc. My database connection cofiguration is in property file from where it is loaded by spring as a data source bean during context initialization.
Now my problem is - I want to change configuration in properties file (for example change database info) but I can't afford to restart the application server so the new configuration does not load.
How can I re-initialize spring context or some particular beans so the newly defined properties are used?
If you want multiple data source in spring and need to deciding appropriate data source dynamically at runtime you can do this with AbstractRoutingDataSource provided with spring. You have to implement your lookup key logic for determining data-source in method determineCurrentLookupKey(). With this you can map different beans to different data-sources at runtime. following are few questions relating to this context.
How to programatically change databases in Spring with one DataSource?
Also
dynamically change Spring data source