@CreateCache: In-depth analysis of its functions and advantages

1. Preface to @CreateCache

In modern web application development, caching is one of the important means to improve performance and response speed. The @CreateCache annotation is an annotation used to create caches in the JetCache framework. This article will introduce the @CreateCache annotation and its role in cache management.

2. @CreateCache usage example

The following is a simple example using the @CreateCache annotation:

import com.alicp.jetcache.anno.*;
import com.alicp.jetcache.Cache;

public class MyCacheClass {<!-- -->

    @CreateCache(name = "myCache", expire = 60000)
    private Cache<String, String> cache;

    public void myMethod() {<!-- -->
        // use cache
        String value = cache.get("key");
        if (value == null) {<!-- -->
            // There is no corresponding value in the cache and business logic needs to be executed.
            value = fetchDataFromSource();
            cache.put("key", value);
        }
        // Process the value in the cache
        // ...
    }

    private String fetchDataFromSource() {<!-- -->
        //The logic of obtaining data from the data source
        // ...
        return "data";
    }
}
</code><img class="look-more-preCode contentImg-no-view" src="//i2.wp.com/csdnimg.cn/release/blogv2/dist/pc/img/newCodeMoreBlack.png" alt ="" title="">

In the above example, we created a cache instance named myCache and configured it on the cache field. The cache instance has a key type of String and a value type of String.

In the myMethod method, we first try to get the value with key “key” from the cache. If the value exists in the cache, it is used directly; otherwise, we execute the fetchDataFromSource method to get the data from the data source and put it into the cache.

By using the @CreateCache annotation, we can easily create and configure cache instances in classes, and use cache functions in methods. According to specific needs, you can change the attributes of the annotation, such as the expire attribute that specifies the expiration time of the cache item.

3. A preliminary exploration of @CreateCache

In this part, we will take a deeper look at the basic concepts and usage of the @CreateCache annotation. We’ll discuss how to use this annotation to define the cache’s name, type, and other configuration items, as well as how to invoke and manage the cache in your application.

@CreateCache is an annotation in the JetCache library. JetCache is a Java caching framework that can be used to provide caching capabilities to applications. The @CreateCache annotation is used to create a cache instance on a Java class or method and configure it.

This annotation can be applied at two levels:

Class level: When the @CreateCache annotation is applied to a class, it means that the class defines a cache instance that can be shared and used throughout the class. Class-level annotations are often used to create global or static cache instances to be shared by multiple methods or threads.
Method level: When the @CreateCache annotation is applied to a method, it indicates that the method defines a cache instance that can be used inside the method. Method-level annotations are often used to create specific cache instances to meet method-level caching requirements.

The @CreateCache annotation can configure some properties to define the behavior and characteristics of the cache, for example:

name: Used to specify the name of the cache so that the cache can be referenced and manipulated in code.
cacheType: used to specify the type of cache, such as local cache (LocalCache), remote cache (RemoteCache), etc.
expire: Used to specify the cache expiration time, that is, how long after the cache item will automatically expire.
localLimit: Used to specify the maximum number of cache items that can be accommodated in the local cache.

In addition, the @CreateCache annotation also supports other properties and configuration options to meet different caching needs and scenarios.

Using the @CreateCache annotation, you can easily create and configure cache instances in Java applications, providing simple and flexible caching functions. According to the documentation and specific usage scenarios, you can learn more about the detailed usage and configuration options of annotations.

4. @CreateCache usage scenarios

The @CreateCache annotation is often used in the following scenarios in the JetCache library:

Method result caching: Use the @CreateCache annotation on some computationally complex or time-consuming methods to cache the results of the method. In this way, when the method is called with the same parameters next time, the results can be obtained directly from the cache, avoiding recalculation and improving performance and response speed.
Database query result caching: Use the @CreateCache annotation on the method of executing a database query to cache the query results within a certain time range. In this way, in multiple identical query requests, frequent access to the database can be avoided, and the cached results can be obtained from the cache to reduce the load pressure on the database.
Remote call result caching: Use the @CreateCache annotation on the method of making a remote service call to cache the results of the remote call. In this way, under the same request, the results can be obtained directly from the cache, avoiding frequent remote calls and improving system performance and scalability.
Object caching: Use the @CreateCache annotation on methods or classes that need to cache certain object instances. In this way, object instances can be cached and retrieved directly from the cache when needed, avoiding repeated creation and initialization of objects.

The @CreateCache annotation provides flexible configuration options, allowing developers to adjust the behavior and characteristics of the cache according to specific needs. In the above scenario, by properly configuring the properties of the @CreateCache annotation, the cache expiration time, cache capacity, cache type, etc. can be customized to meet different business needs.

It is necessary to choose the appropriate cache strategy and usage method according to the specific situation and business needs. At the same time, when using the @CreateCache annotation, the consistency and update mechanism of the cache also need to be considered to ensure the correctness and timeliness of the cached data. sex.

5. @CreateCache source code analysis

In order to have a deeper understanding of the implementation principle of the @CreateCache annotation, we will analyze its source code. We’ll look at how annotations work, how they interact with cache middleware, and how they implement cache management and the storage and retrieval of cached data under the hood.

First, you need to understand the definition of the @CreateCache annotation. This annotation is a custom annotation provided by the JetCache framework and is used to mark methods that need to be cached. By checking for the presence of this annotation, JetCache can automatically handle caching logic when a method is called.

According to the definition of the @CreateCache annotation, we can find its source code. The following is the source code of the annotation:

package com.alicp.jetcache.anno;

import java.lang.annotation.*;

@Target({<!-- -->ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
public @interface CreateCache {<!-- -->

    String[] area() default {<!-- -->};

    String name();

    int expire() default 0;

    int localLimit() default 0;

    String cacheType() default "";

    boolean timeUnit() default false;

    String[] cacheTypeBasePackages() default {<!-- -->};

    boolean autoInit() default true;

}
</code><img class="look-more-preCode contentImg-no-view" src="//i2.wp.com/csdnimg.cn/release/blogv2/dist/pc/img/newCodeMoreBlack.png" alt ="" title="">

Now, let us explain each attribute in the annotation one by one:

area(): Specifies the area to which the cache belongs, used to group different cache instances. Multiple cache areas can be used within an application. The default is an empty array, indicating that no specific cache area is specified.
name(): Specifies the name of the cache, which is used to uniquely identify the cache. Within the same cache area, different caches should have different names.
expire(): Specifies the cache expiration time, in milliseconds. After the cache expires, it will automatically expire and be removed. The default value is 0, which means no expiration time is set.
localLimit(): Specifies the maximum size limit of the local cache. When the data entries in the cache exceed this limit, the eviction policy of the local cache will be triggered.
cacheType(): Specifies the cache type. You can choose different cache types, such as local cache, remote cache or custom cache type. The default is an empty string, indicating that the cache type is not specified and the default cache type will be used.
timeUnit(): Specifies whether the expiration time uses time units. The default is false, which means the expiration time is directly in milliseconds. If set to true, the time unit needs to be specified in the expire() parameter.
cacheTypeBasePackages(): Specify the packages to be scanned to automatically discover the cache type. JetCache will scan these packages for classes and automatically register them as available cache types.
autoInit(): Indicates whether to automatically initialize the cache. The default is true, which means the cache is automatically initialized when the application starts. If set to false, the cache needs to be initialized manually.

The above is the attribute definition of the @CreateCache annotation. Developers can define and configure a cache suitable for their own applications by providing corresponding property values when using this annotation according to their own needs.

By analyzing the source code of the @CreateCache annotation, we can better understand its function and usage. This annotation provides a flexible cache definition and configuration method for the JetCache framework, allowing developers to easily use cache to improve application performance and response speed.

6. Common scenarios of @CreateCache

The @CreateCache annotation is often used in the following scenarios in the JetCache library:

Method result caching: Use the @CreateCache annotation on some computationally complex or time-consuming methods to cache the results of the method. In this way, when the method is called with the same parameters next time, the results can be obtained directly from the cache, avoiding recalculation and improving performance and response speed.
Database query result caching: Use the @CreateCache annotation on the method of executing a database query to cache the query results within a certain time range. In this way, in multiple identical query requests, frequent access to the database can be avoided, and the cached results can be obtained from the cache to reduce the load pressure on the database.
Remote call result caching: Use the @CreateCache annotation on the method of making a remote service call to cache the results of the remote call. In this way, under the same request, the results can be obtained directly from the cache, avoiding frequent remote calls and improving system performance and scalability.
Object caching: Use the @CreateCache annotation on methods or classes that need to cache certain object instances. In this way, object instances can be cached and retrieved directly from the cache when needed, avoiding repeated creation and initialization of objects.

The @CreateCache annotation provides flexible configuration options, allowing developers to adjust the behavior and characteristics of the cache according to specific needs. In the above scenario, by properly configuring the properties of the @CreateCache annotation, the cache expiration time, cache capacity, cache type, etc. can be customized to meet different business needs.

It is necessary to choose the appropriate caching strategy and usage method based on the specific situation and business demand scenarios; at the same time, when using the @CreateCache annotation, the cache consistency and update mechanism also need to be considered to ensure the correctness of the cached data. sex and timeliness.

7. Notes on @CreateCache

When using the @CreateCache annotation, the following are some considerations:

Import the correct dependencies: Use the @CreateCache annotation to introduce JetCache-related dependencies. Make sure that JetCache’s dependency is added correctly in the project’s build file (such as pom.xml).
Configuring cache properties: The @CreateCache annotation provides multiple properties for configuring the cache, such as name, expire, cacheType code>etc. Make sure to set these properties correctly to meet your business needs.
Inject cache instance: When using the @CreateCache annotation, the target field of the annotation should be an instance of the Cache type. Make sure to inject the cache instance correctly so that the cache can be used in the method.
Thread safety: JetCache’s cache implementation is generally thread-safe, but if you use the cache in a concurrent environment, you need to ensure that thread safety is handled correctly. You can use the atomic operations provided by JetCache, such as putIfAbsent, computeIfAbsent, etc., or handle synchronization issues yourself.
Cache consistency: Pay attention to cache consistency issues when using cache. When updating the data source, you need to ensure that the corresponding cached data is updated in a timely manner to avoid reading expired or inconsistent cached values.
Monitoring and configuration management: JetCache provides some monitoring and configuration management functions, such as providing a JMX interface and supporting cache configuration through configuration files. You can configure and use these features as needed to better manage and monitor your cache.
Version compatibility and stability: Make sure the version of JetCache you use is compatible with the versions of your project and dependencies, and choose a stable version. Timely update JetCache to the latest version for better performance and feature improvements.

8. @CreateCache Summary

Through the article, we have comprehensively introduced and discussed the @CreateCache annotation. We have an in-depth understanding of the features, usage, and common application scenarios of this annotation. We also analyzed its source code and role in cache management. Finally, we summarize the key points and best practices to note when using this annotation.

By using the @CreateCache annotation, developers can more easily leverage caching to improve application performance and responsiveness. However, properly configuring and using caches is still a complex task that requires careful tuning based on specific business needs. I hope this article provides some useful reference and guidance for you to understand and use the @CreateCache annotation.