java実現キャッシュ（転載）

package lhm.hcy.guge.frameset.cache;  
  
import java.util.*;  
  
/** 
 * <p>Title: </p> 
 * 
 * <p>Description:     </p> 
 * Deep blue 2008-11-28 think 
 *       ： chche                     ，                  
 * <p>Copyright: Copyright (c) 2008</p> 
 * 
 * <p>Company: </p> 
 * 
 * @author Deepblue  2008-11-11 
 * @version 1.0 
 */  
public class CacheManager {  
    private static HashMap cacheMap = new HashMap();  
  
    //         
    private CacheManager() {  
        super();  
    }  
    //          
    public static boolean getSimpleFlag(String key){  
        try{  
            return (Boolean) cacheMap.get(key);  
        }catch(NullPointerException e){  
            return false;  
        }  
    }  
    public static long getServerStartdt(String key){  
        try {  
            return (Long)cacheMap.get(key);  
        } catch (Exception ex) {  
            return 0;  
        }  
    }  
    //          
    public synchronized static boolean setSimpleFlag(String key,boolean flag){  
        if (flag && getSimpleFlag(key)) {//            
            return false;  
        }else{  
            cacheMap.put(key, flag);  
            return true;  
        }  
    }  
    public synchronized static boolean setSimpleFlag(String key,long serverbegrundt){  
        if (cacheMap.get(key) == null) {  
            cacheMap.put(key,serverbegrundt);  
            return true;  
        }else{  
            return false;  
        }  
    }  
  
  
    //    。        
    private synchronized static Cache getCache(String key) {  
        return (Cache) cacheMap.get(key);  
    }  
  
    //            
    private synchronized static boolean hasCache(String key) {  
        return cacheMap.containsKey(key);  
    }  
  
    //        
    public synchronized static void clearAll() {  
        cacheMap.clear();  
    }  
  
    //         ,    HASHMAP      ，     KEY    TYPE      
    public synchronized static void clearAll(String type) {  
        Iterator i = cacheMap.entrySet().iterator();  
        String key;  
        ArrayList<String> arr = new ArrayList<String>();  
        try {  
            while (i.hasNext()) {  
                java.util.Map.Entry entry = (java.util.Map.Entry) i.next();  
                key = (String) entry.getKey();  
                if (key.startsWith(type)) { //          
                    arr.add(key);  
                }  
            }  
            for (int k = 0; k < arr.size(); k++) {  
                clearOnly(arr.get(k));  
            }  
        } catch (Exception ex) {  
            ex.printStackTrace();  
        }  
    }  
  
    //         
    public synchronized static void clearOnly(String key) {  
        cacheMap.remove(key);  
    }  
  
    //      
    public synchronized static void putCache(String key, Cache obj) {  
        cacheMap.put(key, obj);  
    }  
  
    //        
    public static Cache getCacheInfo(String key) {  
  
        if (hasCache(key)) {  
            Cache cache = getCache(key);  
            if (cacheExpired(cache)) { //            
                cache.setExpired(true);  
            }  
            return cache;  
        }else  
            return null;  
    }  
  
    //        
    public static void putCacheInfo(String key, Cache obj, long dt,boolean expired) {  
        Cache cache = new Cache();  
        cache.setKey(key);  
        cache.setTimeOut(dt + System.currentTimeMillis()); //           
        cache.setValue(obj);  
        cache.setExpired(expired); //       ，     FALSE  
        cacheMap.put(key, cache);  
    }  
    //            
    public static void putCacheInfo(String key,Cache obj,long dt){  
        Cache cache = new Cache();  
        cache.setKey(key);  
        cache.setTimeOut(dt+System.currentTimeMillis());  
        cache.setValue(obj);  
        cache.setExpired(false);  
        cacheMap.put(key,cache);  
    }  
  
    //          
    public static boolean cacheExpired(Cache cache) {  
        if (null == cache) { //          
            return false;  
        }  
        long nowDt = System.currentTimeMillis(); //          
        long cacheDt = cache.getTimeOut(); //           
        if (cacheDt <= 0||cacheDt>nowDt) { //          ,             ，  FALSE  
            return false;  
        } else { //            
            return true;  
        }  
    }  
  
    //          
    public static int getCacheSize() {  
        return cacheMap.size();  
    }  
  
    //            
    public static int getCacheSize(String type) {  
        int k = 0;  
        Iterator i = cacheMap.entrySet().iterator();  
        String key;  
        try {  
            while (i.hasNext()) {  
                java.util.Map.Entry entry = (java.util.Map.Entry) i.next();  
                key = (String) entry.getKey();  
                if (key.indexOf(type) != -1) { //          
                    k++;  
                }  
            }  
        } catch (Exception ex) {  
            ex.printStackTrace();  
        }  
  
        return k;  
    }  
  
    //                
    public static ArrayList<String> getCacheAllkey() {  
        ArrayList a = new ArrayList();  
        try {  
            Iterator i = cacheMap.entrySet().iterator();  
            while (i.hasNext()) {  
                java.util.Map.Entry entry = (java.util.Map.Entry) i.next();  
                a.add((String) entry.getKey());  
            }  
        } catch (Exception ex) {} finally {  
            return a;  
        }  
    }  
  
    //                   
    public static ArrayList<String> getCacheListkey(String type) {  
        ArrayList a = new ArrayList();  
        String key;  
        try {  
            Iterator i = cacheMap.entrySet().iterator();  
            while (i.hasNext()) {  
                java.util.Map.Entry entry = (java.util.Map.Entry) i.next();  
                key = (String) entry.getKey();  
                if (key.indexOf(type) != -1) {  
                    a.add(key);  
                }  
            }  
        } catch (Exception ex) {} finally {  
            return a;  
        }  
    }  
  
}  
  
  
package lhm.hcy.guge.frameset.cache;  
  
/** 
 * <p>Title: </p> 
 * 
 * <p>Description:   DTO</p> 
 * 
 * <p>Copyright: Copyright (c) 2008</p> 
 * 
 * <p>Company: </p> 
 * 
 * @author Deepblue  2008-11-11 
 * @version 1.0 
 */  
public class Cache {  
        private String key;//  ID  
        private Object value;//      
        private long timeOut;//      
        private boolean expired; //      
        public Cache() {  
                super();  
        }  
  
        public Cache(String key, Object value, long timeOut, boolean expired) {  
                this.key = key;  
                this.value = value;  
                this.timeOut = timeOut;  
                this.expired = expired;  
        }  
  
        public String getKey() {  
                return key;  
        }  
  
        public long getTimeOut() {  
                return timeOut;  
        }  
  
        public Object getValue() {  
                return value;  
        }  
  
        public void setKey(String string) {  
                key = string;  
        }  
  
        public void setTimeOut(long l) {  
                timeOut = l;  
        }  
  
        public void setValue(Object object) {  
                value = object;  
        }  
  
        public boolean isExpired() {  
                return expired;  
        }  
  
        public void setExpired(boolean b) {  
                expired = b;  
        }  
}  
  
//   ，  
class Test {  
    public static void main(String[] args) {  
        System.out.println(CacheManager.getSimpleFlag("alksd"));  
//        CacheManager.putCache("abc", new Cache());  
//        CacheManager.putCache("def", new Cache());  
//        CacheManager.putCache("ccc", new Cache());  
//        CacheManager.clearOnly("");  
//        Cache c = new Cache();  
//        for (int i = 0; i < 10; i++) {  
//            CacheManager.putCache("" + i, c);  
//        }  
//        CacheManager.putCache("aaaaaaaa", c);  
//        CacheManager.putCache("abchcy;alskd", c);  
//        CacheManager.putCache("cccccccc", c);  
//        CacheManager.putCache("abcoqiwhcy", c);  
//        System.out.println("      ："+CacheManager.getCacheSize());  
//        CacheManager.getCacheAllkey();  
//        CacheManager.clearAll("aaaa");  
//        System.out.println("      ："+CacheManager.getCacheSize());  
//        CacheManager.getCacheAllkey();  
  
  
    }  
}