In -depth analysis of the life cycle in the Java class library running framework
In -depth analysis of the life cycle in the Java class library running framework
Overview:
During the runtime of life cycle, the framework is a design mode in the Java class library that is used to manage the process of creating, initialization, operation, and destruction of objects.It provides a structured method to manage the entire life cycle of the object to ensure the correct treatment of the object at different stages and release resources when needed.This article will in -depth analysis of the runtime of the life cycle runtime in the Java library, introducing its principles, use scenarios, and sample code.
1. The principle of framework when runtime of life cycle:
The framework of the life cycle is mainly implemented by defining the life cycle interface and the use of the life cycle manager.The life cycle interface defines the method that the object should execute at different stages, such as initialization, starting, suspension, recovery, and destruction.The life cycle manager is responsible for managing the life cycle process of the object, and the relevant method of calling the object in the order method of the defined interface method.Through the combination of the life cycle interface and the manager, the automation life cycle management of the object can be realized.
Second, the use of framework when runtime of life cycle:
During the runtime of life cycle, the framework can be widely used in various components in the Java class library, such as web applications, database connection pools, thread pools, etc.The following are several common usage scenarios:
1. Web application: In web applications, you can use the life cycle to manage the life cycle of the service or Filter.For example, in the initialization phase, the configuration file and initialization database can be loaded, and resources and closing the database connection can be released during the destruction stage.
2. Database connection pool: The framework of the life cycle can be used to manage the life cycle of the connection object in the database connection pool.In the initialization phase, the connection object can be created and the connection parameters can be set, and the connection can be closed and the resources can be released during the destruction phase.
3. Thread pool: The framework of the life cycle is also applicable to the life cycle of the thread in the management thread pool.In the initialization phase, threads can be created and related parameters can be initialized, and threads can be stopped during the destruction phase and resources can be released.
Third, sample code:
Below is a simple example code, demonstrating how to use the life cycle to manage the life cycle of a custom component when running the framework.
import org.apache.commons.lang3.StringUtils;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
public class CustomComponent {
private String name;
public CustomComponent(String name) {
this.name = name;
}
@PostConstruct
public void init() {
System.out.println("Initializing CustomComponent: " + name);
// Initialize related logic
}
public void execute() {
if (StringUtils.isNotBlank(name)) {
System.out.println("Executing CustomComponent: " + name);
// Execute related logic
}
}
@PreDestroy
public void destroy() {
System.out.println("Destroying CustomComponent: " + name);
// Destroy relevant resources
}
}
In the above example, we define a custom component called Customcomponent.By marking the @PostConStruct annotation on the init () method and the @Predestroy annotation on the Destroy () method, we tell the life cycle manager to perform these methods during the initialization and destruction phase of the object.By calling the Execute () method, we can perform business logic of custom components during the operation phase.
Next, we can use the Spring framework or other life cycle managers to create and manage instances of the Customcomponent to ensure that their Init (), Execute (), and Destroy () methods are called at the right time.For example, the example code using the Spring framework is as follows:
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class Application {
public static void main(String[] args) {
try (AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext()) {
context.register(Config.class);
context.refresh();
CustomComponent component = context.getBean(CustomComponent.class);
component.execute();
}
}
}
In the above example, we use AnnotionConfigApplicationContext to create a Spring application context, and register the Config class as the configuration class.In the Config class, we can use the @Bean annotation to inject the Customcomponent as a spring bean.By calling the Context.refresh () method, Spring will start the application context and create a CustomcomPonent instance.In the main method, we can get the CustomcomPonent instance and call the Execute () method to perform business logic.After the application is running, Spring will automatically call the Destroy () method to destroy the CustomcomPonent instance.
Summarize:
The framework of life cycle is a very useful tool that can standardize and simplify the life cycle management of the object.This article deeply analyzes the principle of framework, usage scenario, and sample code in the life cycle of the Java library.By reasonable use of the framework of the life cycle, we can better manage the process of creating, initialization, operation, and destruction of objects to improve the maintenance and stability of the application.
