import java.util.HashMap;

import java.util.Map;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.Executors;

import java.util.concurrent.ScheduledExecutorService;

import java.util.concurrent.TimeUnit;

public class DataNormalizer {

private final ConcurrentHashMap<String, String> dataCache = new ConcurrentHashMap<>();

private final int timeoutSeconds;

private final ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();

public DataNormalizer(int timeoutSeconds) {

this.timeoutSeconds = timeoutSeconds;

scheduleCleanup();

}

// Method to normalize incoming data

public String normalizeData(String key, String data) {

// If data already exists in cache, check if it's expired

if (dataCache.containsKey(key)) {

String cachedData = dataCache.get(key);

if (isExpired(cachedData)) {

// Remove expired data

dataCache.remove(key);

return null; // Or handle expired data differently

} else {

return cachedData; // Return cached data

}

}

// Normalize the data (example normalization - convert to lowercase)

String normalizedData = data.toLowerCase();

// Store the normalized data in the cache with a timeout

dataCache.put(key, normalizedData);

return normalizedData;

}

private boolean isExpired(String data) {

long lastUpdated = System.currentTimeMillis() - dataCache.get(data).length();

return lastUpdated > (timeoutSeconds * 1000);

}

// Schedule a task to clean up expired data periodically

private void scheduleCleanup() {

scheduler.scheduleAtFixedRate(() -> {

// Remove expired data from the cache

dataCache.entrySet().removeIf(entry -> isExpired(entry.getValue()));

System.out.println("Data cleanup completed."); // Log cleanup

}, 0, timeoutSeconds, TimeUnit.SECONDS);

}

// Shutdown the scheduler when the DataNormalizer is no longer needed

public void shutdown() {

scheduler.shutdown();

}

public static void main(String[] args) throws InterruptedException {

DataNormalizer normalizer = new DataNormalizer(5); // Timeout of 5 seconds

String data1 = "Hello World";

String normalized1 = normalizer.normalizeData("key1", data1);

System.out.println("Normalized data1: " + normalized1);

String data2 = "HELLO WORLD";

String normalized2 = normalizer.normalizeData("key1", data2);

System.out.println("Normalized data2: " + normalized2);

// Wait for a few seconds to simulate data arriving later

Thread.sleep(6000); // Wait for data to expire

String data3 = "HELLO WORLD";

String normalized3 = normalizer.normalizeData("key1", data3);

System.out.println("Normalized data3: " + normalized3);

normalizer.shutdown();

}

}