Detailed explanation of the technical principles of the JSR107 API and SPI framework in the Java library
The JSR107 API and SPI framework in the Java class library provides a standardized access method for Java programmers.JSR107 is an abbreviation of Java specification requests, indicating that the API is formed by professionals in the Java community through a series of discussions and confirmation.SPI is the standard extension mechanism of Java, which allows developers to expand the existing framework without modifying the original code.
JSR107 API is the standardization of the Java Caching API.It provides a set of interfaces to define the operation of cache, such as obtaining, placing and deleting cache items.It also defines the concepts of different types of cache, cache monitoring, and cache configuration.Java programmers can use the JSR107 API to write code that has nothing to do with the specific cache, so that their programs have better portability and scalability.
The SPI framework is a way to write a plug -in code.In Java, the SPI framework uses standard interfaces and ways to implement separation, so that some parts of the program can be replaced or expanded.The SPI framework found and loaded a class of an interface by looking for a specific configuration file in the class path.These configuration files can be used by plug -in providers to inform the applications of which parts can be replaced or extended.
The following is a simple example that shows how to use the JSR107 API and SPI framework to achieve custom cache expansion:
First, define a cache operation interface:
public interface MyCache {
void put(String key, String value);
String get(String key);
void remove(String key);
}
Then, implement the interface:
public class MyCacheImpl implements MyCache {
private final Map<String, String> cache = new HashMap<>();
@Override
public void put(String key, String value) {
cache.put(key, value);
}
@Override
public String get(String key) {
return cache.get(key);
}
@Override
public void remove(String key) {
cache.remove(key);
}
}
Next, create a specific configuration file called `javax.cache.spi.cachingProvider`, which contains a full -limited name of the custom cache implementation class.
Finally, use the JSR107 API to load custom cache implementation in the code:
import javax.cache.Cache;
import javax.cache.CacheManager;
import javax.cache.Caching;
import javax.cache.spi.CachingProvider;
public class Main {
public static void main(String[] args) {
CachingProvider cachingProvider = Caching.getCachingProvider();
CacheManager cacheManager = cachingProvider.getCacheManager();
Cache<String, String> cache = cacheManager.getCache("myCache");
cache.put("key", "value");
String value = cache.get("key");
System.out.println(value);
cachingProvider.close();
}
}
In this example, we use the `Caching` class in the JSR107 API to obtain the cache provider and obtain the cache manager through the cache provider.Then, we use the `CacheManager.GetCache` method to obtain a cache instance called` mycache "` and operate.
In summary, the technical principles of the JSR107 API and SPI frameworks are to make the Java program have better portability and scalability.The JSR107 API provides a standardized access method for cache implementation, and the SPI framework allows developers to replace or extend the existing framework by configuration files.By using these technologies, Java programmers can easily use the cache, and can easily open different cache implementation with their code.
