簡單緩存的實現，相當牛叉！自己看吧，只有50行代碼。

package org.xiu.activity.OrderList.view;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
/**
 * @Author: Relice
 * @Des: 記錄好的代碼
 * 下面是一個簡單緩存的實現，相當牛叉！自己看吧，只有50行代碼。
 */
public class OptiCache<K, V> {
    private final Lock lock = new ReentrantLock();
    private final int maxCapacity;
    private final Map<K, V> eden;
    private final Map<K, V> perm;
    public OptiCache(int maxCapacity) {
        this.maxCapacity = maxCapacity;
        this.eden = new ConcurrentHashMap<K, V>(maxCapacity);
        this.perm = new WeakHashMap<K, V>(maxCapacity);
    }
    public V get(K k) {
        V v = this.eden.get(k);
        if (v == null) {
            lock.lock();
            try {
                v = this.perm.get(k);
            } finally {
                lock.unlock();
            }
            if (v != null) {
                this.eden.put(k, v);
            }
        }
        return v;
    }
    public void put(K k, V v) {
        if (this.eden.size() >= maxCapacity) {
            lock.lock();
            try {
                this.perm.putAll(this.eden);
            } finally {
                lock.unlock();
            }
            this.eden.clear();
        }
        this.eden.put(k, v);
    }
}