Issue
Spring boot comes with many cool features. My favourite one is a type-safe configuration mechanism through href="http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-external-config-typesafe-configuration-properties">@ConfigurationProperties and corresponding yml/properties files. I'm writing a library that configures Cassandra connection via Datastax Java driver. I want to allow developers to configure Cluster and Session objects by simply editing yml file. This is easy in spring-boot. But I want to allow her/him configure multiple connections this way. In PHP framework - Symfony it is as easy as:
doctrine:
dbal:
default_connection: default
connections:
default:
driver: "%database_driver%"
host: "%database_host%"
port: "%database_port%"
dbname: "%database_name%"
user: "%database_user%"
password: "%database_password%"
charset: UTF8
customer:
driver: "%database_driver2%"
host: "%database_host2%"
port: "%database_port2%"
dbname: "%database_name2%"
user: "%database_user2%"
password: "%database_password2%"
charset: UTF8
(this snippet comes from Symfony documentation)
Is it possible in spring-boot using ConfigurationProperties? Should I nest them?
Solution
You could actually use type-safe nested ConfigurationProperties.
@ConfigurationProperties
public class DatabaseProperties {
private Connection primaryConnection;
private Connection backupConnection;
// getter, setter ...
public static class Connection {
private String host;
// getter, setter ...
}
}
Now you can set the property primaryConnection.host.
If you don't want to use inner classes then you can annotate the fields with @NestedConfigurationProperty.
@ConfigurationProperties
public class DatabaseProperties {
@NestedConfigurationProperty
private Connection primaryConnection; // Connection is defined somewhere else
@NestedConfigurationProperty
private Connection backupConnection;
// getter, setter ...
}
See also the Reference Guide and Configuration Binding Docs.
Answered By - Roland Weisleder
Answer Checked By - Mildred Charles (JavaFixing Admin)
