Analysis of the technical principle of Java core cache framework
Analysis of the technical principle of Java core cache framework
In the development of modern Java applications, cache is a very important concept.The cache function is to store some frequent access data in the application to improve the performance and response speed of the system.The Java core cache framework is a tool for managing and using cache, which can effectively handle data storage and retrieval.
The technical principle of the Java core cache framework is based on the following concepts:
1. Data storage and retrieval: Java's core cache framework is stored in memory to improve the retrieval speed of the data.When the application needs to access the data, it first finds the data in the cache.If the data exists in the cache, it returns directly to the application to avoid access to the database or other external storage systems.If the data is not in the cache, the data is obtained from the external storage system and it is stored in the cache to prepare for future access.
2. Data update and failure mechanism: The Java core cache framework realizes a set of data updates and failure mechanisms to ensure that the data in the cache is consistent with the data in the external storage system.When external data changes, the cache will update your data accordingly.This process can be carried out based on time stamps, expired time, event driving.In addition, the cache also supports manual failure, so that developers can actively delete the specified data from the cache when needed.
3. Cache strategy and storage algorithm: The Java core cache framework provides a variety of cache strategies and storage algorithms to meet different application scenarios and needs.Common cache strategies include advanced first -out (FIFO), minimum use (LRU), minimum use (LFU), and so on.The storage algorithm can be selected according to the data access mode and size to maximize the performance and efficiency of the cache.
The following is a simple example, demonstrating how to use the Java core cache framework for data storage and retrieval:
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import java.util.concurrent.TimeUnit;
public class CacheExample {
private static Cache<String, String> cache = CacheBuilder.newBuilder()
.expireaFTERWRITE (5, Timeunit.minutes) // Set the cache failure time
.maximumsize (100) // Set the maximum capacity of the cache
.build();
public static void main(String[] args) {
// Obtain data from the cache
String data = cache.getIfPresent("key");
if (data != null) {
System.out.println ("Obtain data from the cache:" + data);
} else {
// Obtain data from the external storage system
String externalData = getDataFromExternalStorage("key");
System.out.println ("Obtain data from an external storage system:" + Externaldata);
// Store the data into the cache
cache.put("key", externalData);
}
}
private static String getDataFromExternalStorage(String key) {
// Get the logic of data from the external storage system
return "data";
}
}
In the above examples, we use the Cachebuilder class provided by Google's Guava library to build cache objects.By calling the `ExpireAFTERWRITE` method, we set the cache failure time for 5 minutes.By calling the `Maximumsize" method, we set up the maximum capacity of the cache to 100 data.
In the `Main` method, we first try to obtain data from the cache. If the data exists, return it directly to the application.Otherwise, we call the `GetdataFromexternalstorage method to obtain data from the external storage system and store it in the cache.In this way, when you visit the same data again next time, you can directly obtain from the cache to avoid access to the external storage system.
To sum up, the Java core cache framework is stored in memory by storing the frequent access to the system to improve the performance and response speed of the system.Its technical principles include data storage and retrieval, data update and failure mechanism, and cache strategies and storage algorithms.Developers can use the Java core cache framework to optimize the data storage and retrieval process according to the needs of the application to improve the performance and scalability of the system.
