Ehcache简单使用二

Ehcache是Java虚拟机级的缓存，其可以用于许多地方。如：被Hibernate用作二级缓存，Web页缓存、Web页片段缓存、Session同步等。

官方主页：http://ehcache.org/

 

主要测试类：

[java]  view plain copy

1. package my.test.ehcache1;  
2.   
3. import java.io.InputStream;  
4. import java.lang.management.ManagementFactory;  
5.   
6. import javax.management.MBeanServer;  
7.   
8. import net.sf.ehcache.Cache;  
9. import net.sf.ehcache.CacheManager;  
10. import net.sf.ehcache.Element;  
11. import net.sf.ehcache.management.ManagementService;  
12.   
13. public class EHCacheTest {  
14.   
15.     public static void main(String[] args) {  
16.         InputStream is = EHCacheTest.class  
17.                 .getResourceAsStream("/my/test/ehcache1/ehcache.xml");  
18.         //读入配置  
19.         CacheManager cacheManager = new CacheManager(is);  
20.         //打印初始缓存  
21.         String[] cacheNames = cacheManager.getCacheNames();  
22.         printNames(cacheNames);  
23.         //移除缓存  
24.         cacheManager.removeCache("sampleDistributedCache1");  
25.         cacheNames = cacheManager.getCacheNames();  
26.         printNames(cacheNames);  
27.   
28.         //新建缓存  
29.         Cache cache = new Cache("Test1", 100, true, false, 10, 10);  
30.         cacheManager.addCache(cache);  
31.         cacheNames = cacheManager.getCacheNames();  
32.         printNames(cacheNames);  
33.         cache.put(new Element("test1", "value1"));  
34.           
35.         //得到缓存并插入值（这里监听器被调用）  
36.         cache = cacheManager.getCache("sampleCache3");  
37.         for (int i = 0; i < 20; i++) {  
38.             cache.put(new Element("key" + i, "value" + i));  
39.         }  
40.         cache.get("key10");  
41.           
42.         // distributed -- rmi同步  
43.         cache = cacheManager.getCache("sampleDistributedCache2");  
44.         for (int i = 0; i < 100; i++) {  
45.             cache.put(new Element("key" + i , "value" + i));  
46.         }  
47.           
48.         //注册被管理的Bean  
49.         // JMX -- jconsole(MBeanServer)  
50.         MBeanServer mBeanServer = ManagementFactory.getPlatformMBeanServer();  
51.         ManagementService.registerMBeans(cacheManager, mBeanServer, true, true,  
52.                 true, true);  
53.   
54.         for (int i = 0; i < 10; i++) {  
55.             Element temp = cache.get("ehcache");  
56.             if (temp != null) {  
57.                 System.out.println(temp.getValue());  
58.             } else {  
59.                 System.out.println("NotFound");  
60.             }  
61.             try {  
62.                 Thread.sleep(10000);  
63.             } catch (InterruptedException e) {  
64.                 e.printStackTrace();  
65.             }  
66.         }  
67.     }  
68.   
69.     private static void printNames(String[] names) {  
70.         System.out.println("=======================");  
71.         for (int i = 0; i < names.length; i++) {  
72.             System.out.println(names[i]);  
73.         }  
74.     }  
75.   
76. }  

 

Cache事件监听器工厂类：

[java]  view plain copy

1. package my.test.ehcache1;  
2.   
3. import java.util.Properties;  
4.   
5. import net.sf.ehcache.event.CacheEventListener;  
6. import net.sf.ehcache.event.CacheEventListenerFactory;  
7.   
8. public class CacheEvtLstnFac extends CacheEventListenerFactory {  
9.   
10.     @Override  
11.     public CacheEventListener createCacheEventListener(Properties arg0) {  
12.         return new CacheEvtLstn();  
13.     }  
14.   
15. }  

 

Cache事件监听器类：

[java]  view plain copy

1. package my.test.ehcache1;  
2.   
3. import net.sf.ehcache.CacheException;  
4. import net.sf.ehcache.Ehcache;  
5. import net.sf.ehcache.Element;  
6. import net.sf.ehcache.event.CacheEventListener;  
7.   
8. public class CacheEvtLstn implements CacheEventListener {  
9.       
10.     public Object clone() {  
11.         return this;  
12.     }  
13.       
14.     public void dispose() {  
15.         // TODO Auto-generated method stub  
16.   
17.     }  
18.   
19.     public void notifyElementEvicted(Ehcache arg0, Element arg1) {  
20.         System.out.println(arg1.getKey() + "=" + arg1.getValue()  
21.                 + " has been evicted");  
22.     }  
23.   
24.     public void notifyElementExpired(Ehcache arg0, Element arg1) {  
25.         // TODO Auto-generated method stub  
26.   
27.     }  
28.   
29.     public void notifyElementPut(Ehcache arg0, Element arg1)  
30.             throws CacheException {  
31.         System.out.println(arg1.getKey() + "=" + arg1.getValue()  
32.                 + " has been added");  
33.     }  
34.   
35.     public void notifyElementRemoved(Ehcache arg0, Element arg1)  
36.             throws CacheException {  
37.         // TODO Auto-generated method stub  
38.   
39.     }  
40.   
41.     public void notifyElementUpdated(Ehcache arg0, Element arg1)  
42.             throws CacheException {  
43.         // TODO Auto-generated method stub  
44.   
45.     }  
46.   
47.     public void notifyRemoveAll(Ehcache arg0) {  
48.         // TODO Auto-generated method stub  
49.   
50.     }  
51.   
52. }  

 

xml配置文件：更改官方包中的样例文件ehcache.xml中的sampleCache3为如下形式：

[xhtml]  view plain copy

1. <cache name="sampleCache3"  
2.            maxElementsInMemory="10"  
3.            eternal="false"  
4.            overflowToDisk="false"  
5.            timeToIdleSeconds="300"  
6.            timeToLiveSeconds="600"  
7.            diskPersistent="false"  
8.            diskExpiryThreadIntervalSeconds="1"  
9.            memoryStoreEvictionPolicy="LFU">  
10.            <cacheEventListenerFactory class="my.test.ehcache1.CacheEvtLstnFac" properties=""/>  
11.      </cache>  

 

输出结果：

2009-12-13 11:36:02 net.sf.ehcache.distribution.RMICacheManagerPeerListener <init>
警告: Explicitly setting the listener hostname to 'localhost' is not recommended. It will only work if all CacheManager peers are on the same machine.
=======================
sampleDistributedCache2
sampleCache2
sampleCache1
sample/DistributedCache3
sampleDistributedCache1
sampleCache3
=======================
sampleDistributedCache2
sampleCache2
sampleCache1
sample/DistributedCache3
sampleCache3
=======================
sampleDistributedCache2
sampleCache2
Test1
sampleCache1
sample/DistributedCache3
sampleCache3
key0=value0 has been added
key1=value1 has been added
key2=value2 has been added
key3=value3 has been added
key4=value4 has been added
key5=value5 has been added
key6=value6 has been added
key7=value7 has been added
key8=value8 has been added
key9=value9 has been added
key0=value0 has been evicted
key10=value10 has been added
key2=value2 has been evicted
key11=value11 has been added
key1=value1 has been evicted
key12=value12 has been added
key4=value4 has been evicted
key13=value13 has been added
key9=value9 has been evicted
key14=value14 has been added
key7=value7 has been evicted
key15=value15 has been added
key5=value5 has been evicted
key16=value16 has been added
key14=value14 has been evicted
key17=value17 has been added
key12=value12 has been evicted
key18=value18 has been added
key8=value8 has been evicted
key19=value19 has been added
NotFound

 

解释：

首先打印配置文件中的cache名

接着移除了名为“sampleDistributedCache1”的cache，再打印cache名

再添加"Test1"cache，再打印cache名

接着向sampleCache3插入值，因为这个注册了监听器，所以监听器的会输出相应信息

这里配置了maxElementsInMemory="10"，overflowToDisk="false"，表明最多只能存10个条目在内存中，并且不能使用磁盘，因此从10-19添加的条目，会将之前存储的条目从缓存中移除。

 

由于将CacheManager注册到了本地管理BeanServer，所以可以通过jdk的jconsole命令查看管理Bean，如图：

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