JAVA客户端调用memcached

网址：http://www.whalin.com/memcached
最新版本：java_memcached-release_2.0.1

操作示例：

Java代码

import com.danga.MemCached.*;

import org.apache.log4j.*;

public class TestMemcached {

public static void main(String[] args) {

/*初始化SockIOPool，管理memcached的连接池*/

String[] servers = { "192.168.1.20:12111" };

SockIOPool pool = SockIOPool.getInstance();

pool.setServers(servers);

pool.setFailover(true);

pool.setInitConn(10);

pool.setMinConn(5);

pool.setMaxConn(250);

pool.setMaintSleep(30);

pool.setNagle(false);

pool.setSocketTO(3000);

pool.setAliveCheck(true);

pool.initialize();

/*建立MemcachedClient实例*/

MemCachedClient memCachedClient = new MemCachedClient();

for (int i = 0; i < 10; i++) {

/*将对象加入到memcached缓存*/

boolean success = memCachedClient.set("" + i, "Hello!");

/*从memcached缓存中按key值取对象*/

String result = (String) memCachedClient.get("" + i);

System.out.println(String.format("set( %d ): %s", i, success));

System.out.println(String.format("get( %d ): %s", i, result));

}

}

}

Java代码

import com.danga.MemCached.*;

import org.apache.log4j.*;

public class TestMemcached {

public static void main(String[] args) {

/*初始化SockIOPool，管理memcached的连接池*/

String[] servers = { "192.168.1.20:12111" };

SockIOPool pool = SockIOPool.getInstance();

pool.setServers(servers);

pool.setFailover(true);

pool.setInitConn(10);

pool.setMinConn(5);

pool.setMaxConn(250);

pool.setMaintSleep(30);

pool.setNagle(false);

pool.setSocketTO(3000);

pool.setAliveCheck(true);

pool.initialize();

/*建立MemcachedClient实例*/

MemCachedClient memCachedClient = new MemCachedClient();

for (int i = 0; i < 10; i++) {

/*将对象加入到memcached缓存*/

boolean success = memCachedClient.set("" + i, "Hello!");

/*从memcached缓存中按key值取对象*/

String result = (String) memCachedClient.get("" + i);

System.out.println(String.format("set( %d ): %s", i, success));

System.out.println(String.format("get( %d ): %s", i, result));

}

}

}

2.spymemcached客户端API：spymemcached client
网址：http://code.google.com/p/spymemcached/
最新版本：memcached-2.1.jar

操作示例：
用spymemcached将对象存入缓存

Java代码

import java.net.InetSocketAddress;

import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MClient {

public static void main(String[] args){

try{

/*建立MemcachedClient 实例，并指定memcached服务的IP地址和端口号*/

MemcachedClient mc = new MemcachedClient(new InetSocketAddress("192.168.1.20", 12111));

Future<Boolean> b = null;

/*将key值，过期时间(秒)和要缓存的对象set到memcached中*/

b = mc.set("neea:testDaF:ksIdno", 900, "someObject");

if(b.get().booleanValue()==true){

mc.shutdown();

}

}

catch(Exception ex){

ex.printStackTrace();

}

}

}

Java代码

import java.net.InetSocketAddress;

import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MClient {

public static void main(String[] args){

try{

/*建立MemcachedClient 实例，并指定memcached服务的IP地址和端口号*/

MemcachedClient mc = new MemcachedClient(new InetSocketAddress("192.168.1.20", 12111));

Future<Boolean> b = null;

/*将key值，过期时间(秒)和要缓存的对象set到memcached中*/

b = mc.set("neea:testDaF:ksIdno", 900, "someObject");

if(b.get().booleanValue()==true){

mc.shutdown();

}

}

catch(Exception ex){

ex.printStackTrace();

}

}

}

用spymemcached从缓存中取得对象

Java代码

import java.net.InetSocketAddress;

import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MClient {

public static void main(String[] args){

try{

/*建立MemcachedClient 实例，并指定memcached服务的IP地址和端口号*/

MemcachedClient mc = new MemcachedClient(new InetSocketAddress("192.168.1.20", 12111));

/*按照key值从memcached中查找缓存，不存在则返回null */

Object b = mc.get("neea:testDaF:ksIdno ");

mc.shutdown();

}

catch(Exception ex){

ex.printStackTrace();

}

}

}

Java代码

import java.net.InetSocketAddress;

import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MClient {

public static void main(String[] args){

try{

/*建立MemcachedClient 实例，并指定memcached服务的IP地址和端口号*/

MemcachedClient mc = new MemcachedClient(new InetSocketAddress("192.168.1.20", 12111));

/*按照key值从memcached中查找缓存，不存在则返回null */

Object b = mc.get("neea:testDaF:ksIdno ");

mc.shutdown();

}

catch(Exception ex){

ex.printStackTrace();

}

}

}

3.alisoft-xplatform-asf-cache-2.4
这是国产的memcached client.我花时间测试过,配置简单,使用也简单,有很详细的中文文档和英文文档.
网址：http://code.google.com/p/memcache-client-forjava/
最新版本: alisoft-xplatform-asf-cache-2.5.2.jar
使用例子

memcached.xml
=========================
<?xml version="1.0" encoding="UTF-8"?>
<memcached>

<client name="mclient0" compressEnable="true" defaultEncoding="UTF-8" socketpool="pool0">
<errorHandler>com.moit.xplatform.asf.cache.memcached.MemcachedErrorHandler</errorHandler>
</client>

<client name="mclient1" compressEnable="true" defaultEncoding="UTF-8" socketpool="pool1">
<errorHandler>com.moit.xplatform.asf.cache.memcached.MemcachedErrorHandler</errorHandler>
</client>

<client name="mclient2" compressEnable="true" defaultEncoding="UTF-8" socketpool="pool2">
<errorHandler>com.moit.xplatform.asf.cache.memcached.MemcachedErrorHandler</errorHandler>
</client>

<socketpool name="pool0" failover="true" initConn="5" minConn="5" maxConn="250" maintSleep="0"
nagle="false" socketTO="3000" aliveCheck="true">
<servers>192.168.3.251:11211,192.168.3.251:11211</servers>
</socketpool>

<socketpool name="pool1" failover="true" initConn="5" minConn="5" maxConn="250" maintSleep="0"
nagle="false" socketTO="3000" aliveCheck="true">
<servers>192.168.3.251:11211,192.168.3.251:11211</servers>
</socketpool>

<socketpool name="pool2" failover="true" initConn="5" minConn="5" maxConn="250" maintSleep="0"
nagle="false" socketTO="3000" aliveCheck="true">
<servers>192.168.3.251:11211,192.168.3.251:11211</servers>
</socketpool>
<cluster name="cluster1">
<memCachedClients>mclient1,mclient2</memCachedClients>
</cluster>
</memcached>

//用containsKey方法判断cache服务器按指定的key值是否存在。
System.out.println("是否包含了key的数据="+cache.containsKey("key"));
if(cache.containsKey("key"))
{
System.out.println("包含了key的数据");
System.out.println("从cache服务器获得key值");
}
else
{
System.out.println("没有包含了key的数据");
System.out.println("cache服务器,没有数据,则去取数据库数据!");
}

例子：
static ICacheManager<IMemcachedCache> manager;

/**
* 测试MemCached
* @return
*/
public String memcache()
{
manager = CacheUtil.getCacheManager(IMemcachedCache.class,
MemcachedCacheManager.class.getName());
manager.start();
try
{
IMemcachedCache cache = manager.getCache("mclient0");
//根据key得到缓存数据
String a =(String)cache.get("key");
//用containsKey方法判断cache服务器按指定的key值是否存在。
System.out.println("是否包含了key的数据="+cache.containsKey("key"));
if(cache.containsKey("key"))
{
System.out.println("包含了key的数据");
System.out.println("从cache服务器获得key值");
}
else
{
System.out.println("没有包含了key的数据");
System.out.println("cache服务器,没有数据,则去取数据库数据!");
}
//根据key删除服务器上的对应的缓存数据
cache.remove("key");
//根据key保存数据到服务器上
cache.put("key", "你好!");
//设置带有过期时间的例子
//过30分钟
Calendar calendar = Calendar.getInstance();//当前日期
calendar.setTime(new Date());
calendar.add(Calendar.MINUTE, 30);//
cache.remove("keytime");
cache.put("keytime", "30分钟后过期",calendar.getTime());
System.out.println("30分钟后过期=keytime="+cache.get("keytime"));
System.out.println("cache服务器getTime="+calendar.getTime());

}finally{ manager.stop();}
//jsp 使用请参考test.jsp文件
return "testmempage";
}

总结:三种API比较
memcached client for java：较早推出的memcached JAVA客户端API，应用广泛，运行比较稳定。
spymemcached：A simple, asynchronous, single-threaded memcached client written in java. 支持异步，单线程的memcached客户端，用到了java1.5版本的concurrent和nio，存取速度会高于前者，但是稳定性不好，测试中常报timeOut等相关异常。
alisoft-xplatform-asf-cache-2.4 我开始采用,后来发现性能很差,尤其是调用频繁时特别容易出问题.我后来还是采用第一个.现在还没发现什么问题.
由于memcached client for java发布了新版本，性能上有所提高，并且运行稳定，所以建议使用memcached client for java。