在 Java 中如何使用 net.spy.spymemcached 库实现 Memcached 客户端？

已发表: 2020-12-27
使用 net.spy.spymemcached 库的 Memcached Java 客户端教程

几天前，我写了一篇文章，介绍如何通过几个简单的步骤在 Mac OS 上本地设置和启动 MemCached Server。

创建 Memcached Java Client 有三种不同的方法。

  1. net.spy.spymemcached 方法
  2. com.whalin.Memcached – Java –客户端方法
  3. com.googlecode.xmemcached 方法

在本教程中，我们将介绍如何使用net.spy.spymemcached库编写简单的 Java 客户端。 如果您的 Eclipse 环境中有 Maven 项目，请在pom.xml文件中添加以下依赖项。

看一下 set()、get()、delete() 操作。

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< dependency >
< groupId > net . spy < / groupId >
< artifactId > spymemcached < / artifactId >
< version > 2.12.3 < / version >
< / dependency >

更新 pom.xml 文件后，请尝试更新 Java 项目。 接下来是编写简单的Java程序。

实现SpyMemcached.java

库带有非常简单的set() 、 get() 、 delete()操作。 这是一个完整的例子。

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package crunchify . java . tutorials ;
 
import net . spy . memcached . MemcachedClient ;
 
import java . io . IOException ;
import java . net . InetSocketAddress ;
 
/**
* @author Crunchify.com
* Version: 1.0.0
* Details: Use dependency net.spy.spymemcached to retrieve, store Key Value pair from MemCached Server
*
*/
 
public class CrunchifySpyMemcachedClient {
public static void main ( String [ ] args ) {
 
implementCrunchifySpyMemcached ( ) ;
 
}
 
// Approach-1: net.spy.spymemcached
// Use dependency net.spy.spymemcached to retrieve, store Key Value pair from MemCached Server
private static void implementCrunchifySpyMemcached ( ) {
 
// Get a memcache client operating on the specified memcached locations.
MemcachedClient crunchifySpyMemCached ;
try {
crunchifySpyMemCached = new MemcachedClient ( new InetSocketAddress ( "127.0.0.1" , 11211 ) ) ;
 
log ( "=====> Approach-1: SpyMemcached <=====\n" ) ;
 
log ( "==> Connected to Crunchify's Local Server Successfully." + " Host: localhost, Port: 11211" ) ;
 
// Set an object in the cache (using the default transcoder) regardless of any existing value.
// The exp value is passed along to memcached exactly as given, and will be processed per the memcached protocol specification:
 
// The actual value sent may either be Unix time (number of seconds since January 1, 1970, as a 32-bit value), or a number of seconds starting from
// current time. In the latter case, this number of seconds may not exceed 60*60*24*30 (number of seconds in 30 days); if the number sent by a
// client is larger than that, the server will consider it to be real Unix time value rather than an offset from current time.
crunchifySpyMemCached . set ( "Crunchify" , 2000 , "New York" ) ;
crunchifySpyMemCached . set ( "Google" , 2000 , "Mountain View" ) ;
crunchifySpyMemCached . set ( "PayPal" , 2000 , "San Jose" ) ;
crunchifySpyMemCached . set ( "Twitter" , 2000 , "San Francisco" ) ;
crunchifySpyMemCached . set ( "Amazon" , 2000 , "Seattle" ) ;
 
log ( "==> Total 5 Records added to MemCached using net.spy.spymemcached method\n" ) ;
 
// Get with a single key and decode using the default transcoder.
log ( "Key: Google, Value: " + crunchifySpyMemCached . get ( "Google" ) ) ;
log ( "Key: PayPal, Value: " + crunchifySpyMemCached . get ( "PayPal" ) ) ;
log ( "Key: Twitter, Value: " + crunchifySpyMemCached . get ( "Twitter" ) ) ;
log ( "Key: Amazon, Value: " + crunchifySpyMemCached . get ( "Amazon" ) ) ;
log ( "Key: Crunchify, Value: " + crunchifySpyMemCached . get ( "Crunchify" ) ) ;
 
log ( "==> Total 5 Records Retrieved from MemCached using net.spy.spymemcached method\n" ) ;
 
// Delete the given key from the cache.
crunchifySpyMemCached . delete ( "Crunchify" ) ;
log ( "==> Key:Crunchify deleted successfully\n" ) ;
log ( "Key: Crunchify, Value: " + crunchifySpyMemCached . get ( "Crunchify" ) ) ;
log ( "==> If no record found, it returns NULL\n" ) ;
 
} catch ( IOException e ) {
// Prints this throwable and its backtrace to the standard error stream
e . printStackTrace ( ) ;
}
 
}
 
private static void log ( Object object ) {
System . out . println ( object ) ;
 
}
 
}

在本地启动 MemCached Server

转到终端窗口并键入命令memcached -d -p 11211 。

教程：如何在 Mac OS X 上安装和配置 Memcached 进程/服务器？

Eclipse 控制台输出：

只需在上面的程序运行一个 Java 应用程序，您应该会看到这样的结果。

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2018 - 12 - 07 16 : 25 : 45.437 INFO net . spy . memcached . MemcachedConnection :    Setting retryQueueSize to - 1
2018 - 12 - 07 16 : 25 : 45.459 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
===== > Approach - 1 : SpyMemcached < =====
 
== > Connected to Crunchify ' s Local Server Sucessfully . Host : localhost , Port : 11211
== > Total 5 Records added to MemCached using net . spy . spymemcached method
 
Key : Google , Value : Mountain View
Key : PayPal , Value : San Jose
Key : Twitter , Value : San Francisco
Key : Amazon , Value : Seattle
Key : Crunchify , Value : New York
== > Total 5 Records Retrieved from MemCached using net . spy . spymemcached method
 
== > Key : Crunchify deleted successfully
 
Key : Crunchify , Value : null
== > If no record found , it returns NULL
 

如果您在运行程序时遇到任何问题，请告诉我。 在下一个教程we will go over another libraries来设置和获取 Memcached 数据。

接下来是什么？

尝试使用另外两个库的 Memcached Java 客户端教程。

使用 whalin.Memcached-Java-Client 和 googlecode.xmemcached 库的 Memcached Java 客户端教程