简介：

利用memcached可以实现缓存服务器，memcached利用TCP将缓存存储在其他服务器中，且memcached是利用内存看空间来保存缓存数据的，减少了不必要的磁盘I/O。另外，memcached在存储区中对于每一个key都维护一个过期时间，一旦达到这个过期时间，memcached便会自动删除该key，方便了我们的过期检查机制的实现，只需在保存缓存数据时指定过期时间即可。

使用memcache的两种实现jar包：

1、使用net.py.spymemcached：

  1）在pom.xml中添加对net.py.spymemcached的依赖；

<dependency>
        <groupId>net.spy</groupId>
        <artifactId>spymemcached</artifactId>
        <version>2.11.0</version>
</dependency>

2）使用Demo：

 1 package spymemcached;
 2 
 3 import java.io.IOException;
 4 import java.io.Serializable;
 5 import java.net.InetSocketAddress;
 6 import java.util.Date;
 7 
 8 import net.spy.memcached.MemcachedClient;
 9 
10 public class MemcacheUse {
11         private static class MyData implements Serializable {
12                private static final long serialVersionUID = 1L;
13                private long d = new Date().getTime();
14 
15                public String toString() {
16                       return "my data [" + d + "]" ;
17               }
18        }
19 
20         public static void main(String[] args) throws IOException {
21               MyData myData = new MyData();
22               MemcachedClient c = new MemcachedClient (new InetSocketAddress(
23                             "127.0.0.1", 11211));
24                // Store a value (async) for one hour
25               c.set( "someKey", 3600, myData);
26                // Retrieve a value (synchronously).
27               MyData myObject = (MyData) c.get( "someKey");
28               c.shutdown();
29               System. out.println(myObject.toString());
30        }
31 }

3）使用Demo，根据需求进行封装的类：

 1 package com.practice.cache;
 2 
 3 import java.io.IOException;
 4 import java.net.InetSocketAddress;
 5 
 6 import org.springframework.stereotype.Component;
 7 
 8 import net.spy.memcached.MemcachedClient;
 9 import net.spy.memcached.internal.OperationFuture;
10 
11 @Component
12 public class PhonePtCache {
13     private MemcachedClient client;
14 
15     private String hostName = "127.0.0.1";
16     private int port = 11211;
17     private int time = 3600;
18 
19     public PhonePtCache() {
20         try {
21             client = new MemcachedClient(new InetSocketAddress(hostName,port));
22         } catch (IOException e) {
23             e.printStackTrace();
24         }
25     }
26 
27     public OperationFuture<Boolean> set(String key, Object o) {
28         return client.set(key, time, o);
29     }
30 
31     public Object get(String key) {
32         return client.get(key);
33     }
34 
35     public OperationFuture<Boolean> delete(String key) {
36         return client.delete(key);
37     }
38 }

2、使用com.whalin.Memcached-Java-Client
1）在pom.xml中添加依赖：

<dependency>
       <groupId>com.whalin</groupId>
       <artifactId>Memcached-Java-Client</artifactId>
       <version>3.0.2</version>
</dependency>

2）使用Demo

 1 package spymemcached;
 2 
 3 import com.whalin.MemCached.MemCachedClient;
 4 import com.whalin.MemCached.SockIOPool;
 5 
 6 public class MemCacheInvoke {
 7     protected static MemCachedClient mcc = new MemCachedClient();
 8     static{
 9        // 设置缓存服务器列表，当使用分布式缓存的时，可以指定多个缓存服务器。（这里应该设置为多个不同的服务器）
10         String[] servers =
11                 {
12                         "127.0.0.1:11211",
13                 };
14 
15         // 设置服务器权重
16         Integer[] weights = {3, 2};
17         // 创建一个Socked连接池实例
18         SockIOPool pool = SockIOPool. getInstance();
19       // 向连接池设置服务器和权重
20         pool.setServers(servers);
21         pool.setWeights(weights);
22         // set some TCP settings
23         // disable nagle
24         // set the read timeout to 3 secs
25         // and don't set a connect timeout
26         pool.setNagle( false);
27         pool.setSocketTO(3000);
28         pool.setSocketConnectTO(0);
29        // initialize the connection pool
30         pool.initialize();
31     }
32 
33     public static void main(String[] args) {
34         mcc.set("foo" , "This is a test String" );
35         String bar = mcc.get("foo" ).toString();
36         System. out.println(">>> " + bar);
37     }
38 }