使用LinkedHashMap做全局变量缓存

public class LRUCache  extends LinkedHashMap {

	private int maxEntries;

    public LRUCache(int maxEntries) {
        super(16, 0.75f, true);
        this.maxEntries = maxEntries;
    }

    @Override
    protected boolean removeEldestEntry(Map.Entry eldest) {
        return size() > maxEntries;
    }
}

使用方法

public class CacheUtils {

	private static LRUCache cache = new LRUCache<>(8); //存储长度
	
	public static void put(String key, String value) {
		cache.put(key, value);
	}
	
	public static String get(String key) {
		return cache.get(key);
	}
	
	public static void main(String[] args) {
		for (int i = 0; i <= 9; i++) {
			cache.put("key" + i, "abc");
		}
		System.out.println(cache);
		cache.get("key2");
		System.out.println(cache);
		
		cache.put("key" + 10, "abc");
		cache.put("key" + 11, "abc");
		System.out.println(cache);
	}
}