The application of Archaius Scala in the Java class library
Archaius is a library of openflix open source that is used to process dynamic meta -data data for distributed configuration attributes.It provides a convenient way to manage the application configuration, so that the application can dynamically adjust the configuration attribute at any time without restarting the application.Archaius also provides the function of monitoring configuration changes, which can automatically perceive the change in configuration and reload it as needed.
There are many application scenarios using Archaius in the Java library.The following will introduce several common application examples.
1. Dynamic configuration: Using ArchaiiS, you can externalize the configuration attribute of the application and store it in the configuration server or configuration file.You can then use Archaius to dynamically load these configuration attributes without modifying the code or re -deploying the application.For example, you can store the database connection parameters, cache configuration and other applications in the configuration server, and then use Archaius to dynamically load these values when needed.
import com.netflix.config.DynamicPropertyFactory;
import com.netflix.config.DynamicStringProperty;
public class DynamicConfigExample {
private static final DynamicStringProperty DATABASE_URL = DynamicPropertyFactory.getInstance().getStringProperty("database.url", "http://localhost:3306/mydb");
public static void main(String[] args) {
String dbUrl = DATABASE_URL.get();
System.out.println("Database URL: " + dbUrl);
}
}
In the above example, a dynamic configuration attribute object was obtained through the `DynamicPropertyFactory` class, and the key name and default value of the attribute was passed into the attribute.Then, obtain the value of the current configuration through the `Get ()` method.
2. Monitoring configuration change: Archaius can also easily realize the function of monitoring configuration changes.When the configuration attribute changes, you can use the ARCHAIUS listener mechanism to deal with these changes.For example, when the database connection parameters are changed, you can use the Archaius listener to update the database connection pool.
import com.netflix.config.ConfigurationManager;
import com.netflix.config.DynamicPropertyFactory;
import com.netflix.config.DynamicStringProperty;
public class ConfigChangeListenerExample {
private static final DynamicStringProperty DATABASE_URL = DynamicPropertyFactory.getInstance().getStringProperty("database.url", "http://localhost:3306/mydb");
public static void main(String[] args) {
ConfigurationManager.getConfigInstance().addConfigurationListener(configurationEvent -> {
if (configurationEvent.getPropertyName().equals("database.url")) {
System.out.println("Database URL changed. New value: " + DATABASE_URL.get());
// Perform actions based on the new database URL
}
});
}
}
In the above example, a configuration monitor is registered through the method of `adDConfigurationListener ()`.When the configuration attribute changes, the code logic in the listener will be triggered.
3. Dynamic routing: Archaius can also integrate with the Zuul service gateway of Netflix to achieve dynamic routing function.Through the dynamic configuration and monitoring mechanism of Archaius, you can dynamically ask the routing to different back -end services according to the routing rules of the configuration.In this way, you can modify the configuration to adjust the requested route without re -deploying the gateway.
import com.netflix.zuul.context.RequestContext;
import com.netflix.config.DynamicPropertyFactory;
import com.netflix.config.DynamicStringProperty;
public class DynamicRoutingExample {
private static final DynamicStringProperty BACKEND_URL = DynamicPropertyFactory.getInstance().getStringProperty("backend.url", "http://localhost:8080");
public static void main(String[] args) {
String backendUrl = BACKEND_URL.get();
RequestContext context = RequestContext.getCurrentContext();
context.setRouteHost(new URL(backendUrl));
// Process the request using dynamic routing
}
}
In the above example, a dynamic configuration attribute object was obtained through the `DynamicPropertyFactory`, and the key name and default value of the attribute was passed into the attribute.Then, obtain the value of the current configuration through the `Get ()` method and apply it to the routing of the request.
Summary: Archaius is a powerful dynamic configuration library that can be widely used in the Java library.It provides a convenient method for processing distributed configuration attributes and is very flexible, and can be customized according to specific needs.Regardless of dynamic configuration, monitoring configuration change or dynamic routing, Archaius can bring many advantages to Java applications.
