Memcached使用入门——（1）Memcached基础及示例程序

1. What is Memcached?

Memcached是一个免费开源、高性能、分布式的内存对象缓存系统。Memcached是在内存中，为特定数据（字符串或对象）构建key-value的小块数据存储。

2. 下载Memcached的服务器端软件

Windows平台版本下载：http://splinedancer.com/memcached-win32/memcached-1.2.4-Win32-Preview-20080309_bin.zip

Linux平台版本下载：http://memcached.googlecode.com/files/memcached-1.4.10.tar.gz

3. 在服务器上部署Memcached Server

以下以Windows平台为例：

参考：http://www.codeforest.net/how-to-install-memcached-on-windows-machine

下载下来的Windows版本解压到C:/memcached/

在控制台输入命令安装：

c:/memcached/memcached.exe  -d install

启动：

c:/memcached/memcached.exe -d  start

或：

net start "memcached Server"

默认的缓存大小为64M，如果不够用，请打开注册表，找到：

HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/memcached  Server .

将其内容修改为：

“C:/memcached/memcached.exe” -d runservice -m 512

4. 下载Memcached的客户端API包

下载地址：http://spymemcached.googlecode.com/files/memcached-2.5.jar

5. 编写一个Java数据类

package com.sinosuperman.memcached;

import java.io.Serializable;


public class User implements Serializable{ 

	private static final long serialVersionUID = -372274003834027815L;

	String userId;
	
	public User(String userId) { 
		super(); 
		this.userId = userId; 
	}
	
	public String getUserId() { 
		return userId; 
	} 
	
	public void setUserId(String userId) { 
		this.userId = userId; 
	} 
		
	@Override 
	public String toString() { 
		// TODO Auto-generated method stub 
		StringBuffer sb=new StringBuffer(); 
		sb.append("userId="+this.userId); 
		return sb.toString(); 
	} 
} 

6. 编写一个Memcached的客户端

package com.sinosuperman.memcached;

import java.io.IOException;
import java.net.InetSocketAddress;

import net.spy.memcached.MemcachedClient;

public class TestMemcached {
	public static void main(String[] args) throws IOException {
		MemcachedClient cache = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
		for (int i = 1; i < 10; i++) {
			cache.set("T0001" + i, 3600, new User(i + ""));	
		}
		User myObject = (User) cache.get("T00011");
		System.out.println("Get object from mem :" + myObject); 
	} 
}

7. 运行测试

运行结果应该如下：

2011-12-15 17:25:30.276 INFO net.spy.memcached.MemcachedConnection:  Added {QA sa=/127.0.0.1:11211, #Rops=0, #Wops=0, #iq=0, topRop=null, topWop=null, toWrite=0, interested=0} to connect queue
2011-12-15 17:25:30.292 INFO net.spy.memcached.MemcachedConnection:  Connection state changed for sun.nio.ch.SelectionKeyImpl@c62080
Get object from mem :userId=1