更新（首次发布后约4年…）：请注意，在较新版本的ehcache中，缓存项的持久性仅在付费产品中可用。感谢@boday指出这一点。
ehcache很棒。它将为您提供在内存，磁盘或具有溢出到磁盘的内存中实现映射所需的灵活性。如果为java.util.Map使用这个非常简单的包装器，那么使用它就非常简单：
import java.util.Collection;import java.util.List;import java.util.Map;import java.util.Set;import net.sf.ehcache.Cache;import net.sf.ehcache.Element;import org.apache.log4j.Logger;import com.google.common.collect.Sets;public class EhCacheMapAdapter<K,V> implements Map<K,V> { @SuppressWarnings("unused") private final static Logger logger = Logger .getLogger(EhCacheMapAdapter.class); public Cache ehCache; public EhCacheMapAdapter(Cache ehCache) { super(); this.ehCache = ehCache; } // end constructor @Override public void clear() { ehCache.removeAll(); } // end method @Override public boolean containsKey(Object key) { return ehCache.isKeyInCache(key); } // end method @Override public boolean containsValue(Object value) { return ehCache.isValueInCache(value); } // end method @Override public Set<Entry<K, V>> entrySet() { throw new UnsupportedOperationException(); } // end method @SuppressWarnings("unchecked") @Override public V get(Object key) { if( key == null ) return null; Element element = ehCache.get(key); if( element == null ) return null; return (V)element.getObjectValue(); } // end method @Override public boolean isEmpty() { return ehCache.getSize() == 0; } // end method @SuppressWarnings("unchecked") @Override public Set<K> keySet() { List<K> l = ehCache.getKeys(); return Sets.newHashSet(l); } // end method @SuppressWarnings("unchecked") @Override public V put(K key, V value) { Object o = this.get(key); if( o != null ) return (V)o; Element e = new Element(key,value); ehCache.put(e); return null; } // end method @Override public V remove(Object key) { V retObj = null; if( this.containsKey(key) ) { retObj = this.get(key); } // end if ehCache.remove(key); return retObj; } // end method @Override public int size() { return ehCache.getSize(); } // end method @Override public Collection<V> values() { throw new UnsupportedOperationException(); } // end method @Override public void putAll(Map<? extends K, ? extends V> m) { for( K key : m.keySet() ) { this.put(key, m.get(key)); } // end for } // end method} // end class
