Memcached

Memcache is an open source, high-performance distributed memory object cache system. Memcache stores all data in memory and maintains a unified huge Hash table in memory, which can store any type of data, including images, videos, files, and database search results. Transfer data to memory, and then read from memory, thereby greatly improving the reading speed

Install Memcached

(1) Download and install libevent

git clone https://github.com/linxuping/libevent.git
./configure -prefix=/usr/local/libevent
make
make install

(2) Download and install memcached

tar -xvzf memcached-1.5.16.tar.gz
./configure -prefix=/usr/local/memcached -with-libevent=/usr/local/libevent
make
make install

(3) Start memcached

./memcached -u root -d -m 128 -p 11211
./memcached -u root -d -m 128 -p 11212
./memcached -u root -d -m 128 -p 11213

(4) View the memcached process

ps -ef | grep memcached

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(5) Operate memcached

telnet 192.168.138.130 11211
set key 0 0 4
abcd
get key

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Java operation Memcached

package com.memcache.util;

import net.spy.memcached.MemcachedClient;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.io.Serializable;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;

/**
 * @author Administrator
 * @version 1.0
 */
public class Memcache {
    private MemcachedClient client;

    /**
     * 连接memcached
     * @throws IOException
     */
    @Before
    public void connectClient() throws IOException {
        client = new MemcachedClient(new InetSocketAddress("192.168.138.130",11211));
    }


    /**
     * 设置key
     * @throws ExecutionException
     * @throws InterruptedException
     */
    @Test
    public void setKey() throws ExecutionException, InterruptedException {
        Future<Boolean> future = client.set("key1", 0, "Hello World");
        if (future.get().booleanValue()){
            client.shutdown();
        }
    }

    @Test
    public void getKey(){
        Object o = client.get("key1");
        System.out.println("取到的值: "+o);
        client.shutdown();
    }

    /**
     * 设置对象的值
     * @throws ExecutionException
     * @throws InterruptedException
     */
    @Test
    public void setObject() throws ExecutionException, InterruptedException {
        Future<Boolean> future = client.set("key2", 0, new Student());
        if (future.get().booleanValue()){
            client.shutdown();
        }
    }

    /**
     * 客户端路由算法
     * @throws IOException
     * @throws InterruptedException
     */
    @Test
    public void connectList() throws IOException, InterruptedException {
        ArrayList<InetSocketAddress> list = new ArrayList<>();
        list.add(new InetSocketAddress("192.168.138.130",11211));
        list.add(new InetSocketAddress("192.168.138.130",11212));
        list.add(new InetSocketAddress("192.168.138.130",11213));

        //连接Memcached
        client = new MemcachedClient(list);

        for (int i = 0; i < 10; i++){
            client.set("key"+i,0,"value"+i);
            Thread.sleep(1000);
        }

        client.shutdown();
    }
}
class Student implements Serializable {}