oscache 对象缓存

转自 http://benx.iteye.com/blog/606091

Java代码

一、对象缓存
 1、Cache操作类
 import java.util.Date;
 import com.opensymphony.oscache.base.NeedsRefreshException;
 import com.opensymphony.oscache.general.GeneralCacheAdministrator;
 public class BaseCache extends GeneralCacheAdministrator {
     private int refreshPeriod; //过期时间(单位为秒);
     private String keyPrefix; //关键字前缀字符;
     private static final long serialVersionUID = -4397192926052141162L;
     public BaseCache(String keyPrefix,int refreshPeriod){
         super();
         this.keyPrefix = keyPrefix;
         this.refreshPeriod = refreshPeriod;
    }
     //添加被缓存的对象;
     public void put(String key,Object value){
         this.putInCache(this.keyPrefix+"_"+key,value);
    }
     //删除被缓存的对象;
     public void remove(String key){
         this.flushEntry(this.keyPrefix+"_"+key);
    }
     //删除所有被缓存的对象;
     public void removeAll(Date date){
         this.flushAll(date);
    }
     public void removeAll(){
         this.flushAll();
    }
     //获取被缓存的对象;
     public Object get(String key) throws Exception{
         try{
             returnthis.getFromCache(this.keyPrefix+"_"+key,this.refreshPeriod);
         } catch (NeedsRefreshException e) {
             this.cancelUpdate(this.keyPrefix+"_"+key);
             throw e;
        }
    }
}

 2、Cache管理类
 public class CacheManager {
     private BaseCache newsCache;
     private static CacheManager instance;
     private static Object lock = new Object();
     private CacheManager() {
         //这个根据配置文件来，初始BaseCache而已;
         newsCache = new BaseCache("news",120);
    }
     public static CacheManager getInstance(){
         if (instance == null){
             synchronized( lock ){
                 if (instance == null){
                     instance = new CacheManager();
                }
            }
        }
         return instance;
    }
     public void putUser(User news) { newsCache.put(news.getId()+"",news);     }
     public void removeUser(String newsID) {  newsCache.remove(newsID);      }
     public User getUser(int newsID) {
         try {
             return (User) newsCache.get(newsID+"");
         } catch (Exception e) {
             System.out.println("getNews>>newsID["+newsID+"]>>"+e.getMessage());
             User news = new User(newsID);
             this.putUser(news);
             return news;
        }
    }
     public void removeAllNews() {
        newsCache.removeAll();
    }
}

 3、对象Bean
 public class User {
     private int id;
     private String name;
     private String sex;
     private int age;
     private Date accessTime; public User(int id) {
        super();
        this.id = id;
        this.accessTime = new Date(System.currentTimeMillis());
    }
     public String toString() {
        return "User info is : id=" + id + "  accessTime="
              + accessTime.toString();
    }
     public User(String name, String sex, int age) {
        super();
        this.name = name;
        this.sex = sex;
        this.age = age;
    }
     public User() {
    }
     public int getAge() {
        return age;
    }
     public void setAge(int age) {
        this.age = age;
    }
     public String getName() {
        return name;
    }
     public void setName(String name) {
        this.name = name;
    }
     public String getSex() {
        return sex;
    }
     public void setSex(String sex) {
        this.sex = sex;
    }
     public int getId() {
        return id;
    }
     public void setId(int id) {
        this.id = id;
    }
     public Date getAccessTime() {
        return accessTime;
    }
     public void setAccessTime(Date accessTime) {
        this.accessTime = accessTime;
    }
}

 4、测试类
 public class TestObjectCache {
     public static void main(String[] args) {
       CacheManager cm=CacheManager.getInstance();

        TestObjectCache test=new TestObjectCache();
       test.print(cm);
    }

     public void print(CacheManager cm){
        User user=null;
        for (int i = 0; i < 1000; i++) {
            user=cm.getUser(100);
            System.out.println("<<"+i+">>: "+user);
            if(i==10){
               //删除缓存id的对象
               cm.removeUser(100+"");
           }
            if(i==20){
               //删除所有缓存的对象
              cm.removeAllNews();
           }
            // 睡眠部分
            try {
               Thread.sleep(30000);
            } catch (Exception e) {
           }
       }
    }
}