合 缓存数据库之Memcached介绍
编程语言连接Memcached 实例
Java 连接 Memcached 服务
使用 Java 程序连接 Memcached,需要在你的 classpath 中添加 Memcached jar 包。
本站 jar 包下载地址:spymemcached-2.10.3.jar。
Google Code jar 包下载地址:spymemcached-2.10.3.jar(需要科学上网)。
以下程序假定 Memcached 服务的主机为 127.0.0.1,端口为 11211。
连接实例
Java 连接 Memcached
MemcachedJava.java 文件:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | import net.spy.memcached.MemcachedClient; import java.net.*; public class MemcachedJava { public static void main(String[] args) { try{ // 本地连接 Memcached 服务 MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211)); System.out.println("Connection to server successful."); // 关闭连接 mcc.shutdown(); }catch(Exception ex){ System.out.println( ex.getMessage() ); } } } |
该程序中我们使用 InetSocketAddress 连接 IP 为 127.0.0.1 端口 为 11211 的 memcached 服务。
执行以上代码,如果连接成功会输出以下信息:
1 | Connection to server successful. |
set 操作实例
以下使用 java.util.concurrent.Future 来存储数据
MemcachedJava.java 文件:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 | import java.net.InetSocketAddress; import java.util.concurrent.Future; import net.spy.memcached.MemcachedClient; public class MemcachedJava { public static void main(String[] args) { try{ // 连接本地的 Memcached 服务 MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211)); System.out.println("Connection to server successful."); // 存储数据 Future fo = mcc.set("runoob", 900, "Free Education"); // 查看存储状态 System.out.println("set status:" + fo.get()); // 输出值 System.out.println("runoob value in cache - " + mcc.get("runoob")); // 关闭连接 mcc.shutdown(); }catch(Exception ex){ System.out.println( ex.getMessage() ); } } } |
执行程序,输出结果为:
1 2 3 | Connection to server successful. set status:true runoob value in cache - Free Education |
add 操作实例
MemcachedJava.java 文件:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 | import java.net.InetSocketAddress; import java.util.concurrent.Future; import net.spy.memcached.MemcachedClient; public class MemcachedJava { public static void main(String[] args) { try{ // 连接本地的 Memcached 服务 MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211)); System.out.println("Connection to server successful."); // 添加数据 Future fo = mcc.set("runoob", 900, "Free Education"); // 打印状态 System.out.println("set status:" + fo.get()); // 输出 System.out.println("runoob value in cache - " + mcc.get("runoob")); // 添加 fo = mcc.add("runoob", 900, "memcached"); // 打印状态 System.out.println("add status:" + fo.get()); // 添加新key fo = mcc.add("runoob", 900, "All Free Compilers"); // 打印状态 System.out.println("add status:" + fo.get()); // 输出 System.out.println("runoob value in cache - " + mcc.get("runoob")); // 关闭连接 mcc.shutdown(); }catch(Exception ex){ System.out.println(ex.getMessage()); } } } |
replace 操作实例
MemcachedJava.java 文件:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | import java.net.InetSocketAddress; import java.util.concurrent.Future; import net.spy.memcached.MemcachedClient; public class MemcachedJava { public static void main(String[] args) { try { //连接本地的 Memcached 服务 MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211)); System.out.println("Connection to server successful."); // 添加第一个 key=》value 对 Future fo = mcc.set("runoob", 900, "Free Education"); // 输出执行 add 方法后的状态 System.out.println("add status:" + fo.get()); // 获取键对应的值 System.out.println("runoob value in cache - " + mcc.get("runoob")); // 添加新的 key fo = mcc.replace("runoob", 900, "Largest Tutorials' Library"); // 输出执行 set 方法后的状态 System.out.println("replace status:" + fo.get()); // 获取键对应的值 System.out.println("runoob value in cache - " + mcc.get("runoob")); // 关闭连接 mcc.shutdown(); }catch(Exception ex){ System.out.println( ex.getMessage() ); } } } |
append 操作实例
MemcachedJava.java 文件:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | import java.net.InetSocketAddress; import java.util.concurrent.Future; import net.spy.memcached.MemcachedClient; public class MemcachedJava { public static void main(String[] args) { try{ // 连接本地的 Memcached 服务 MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211)); System.out.println("Connection to server successful."); // 添加数据 Future fo = mcc.set("runoob", 900, "Free Education"); // 输出执行 set 方法后的状态 System.out.println("set status:" + fo.get()); // 获取键对应的值 System.out.println("runoob value in cache - " + mcc.get("runoob")); // 对存在的key进行数据添加操作 fo = mcc.append("runoob", 900, " for All"); // 输出执行 set 方法后的状态 System.out.println("append status:" + fo.get()); // 获取键对应的值 System.out.println("runoob value in cache - " + mcc.get("runoob")); // 关闭连接 mcc.shutdown(); }catch(Exception ex) { System.out.println(ex.getMessage()); ] } } |
prepend 操作实例
MemcachedJava.java 文件:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | import java.net.InetSocketAddress; import java.util.concurrent.Future; import net.spy.memcached.MemcachedClient; public class MemcachedJava { public static void main(String[] args) { try{ // 连接本地的 Memcached 服务 MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211)); System.out.println("Connection to server successful."); // 添加数据 Future fo = mcc.set("runoob", 900, "Education for All"); // 输出执行 set 方法后的状态 System.out.println("set status:" + fo.get()); // 获取键对应的值 System.out.println("runoob value in cache - " + mcc.get("runoob")); // 对存在的key进行数据添加操作 fo = mcc.prepend("runoob", 900, "Free "); // 输出执行 set 方法后的状态 System.out.println("prepend status:" + fo.get()); // 获取键对应的值 System.out.println("runoob value in cache - " + mcc.get("runoob")); // 关闭连接 mcc.shutdown(); }catch(Exception ex) { System.out.println(ex.getMessage()); } } } |
CAS 操作实例
MemcachedJava.java 文件:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 | import java.net.InetSocketAddress; import java.util.concurrent.Future; import net.spy.memcached.CASValue; import net.spy.memcached.CASResponse; import net.spy.memcached.MemcachedClient; public class MemcachedJava { public static void main(String[] args) { try{ // 连接本地的 Memcached 服务 MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211)); System.out.println("Connection to server successful."); // 添加数据 Future fo = mcc.set("runoob", 900, "Free Education"); // 输出执行 set 方法后的状态 System.out.println("set status:" + fo.get()); // 使用 get 方法获取数据 System.out.println("runoob value in cache - " + mcc.get("runoob")); // 通过 gets 方法获取 CAS token(令牌) CASValue casValue = mcc.gets("runoob"); // 输出 CAS token(令牌) 值 System.out.println("CAS token - " + casValue); // 尝试使用cas方法来更新数据 CASResponse casresp = mcc.cas("runoob", casValue.getCas(), 900, "Largest Tutorials-Library"); // 输出 CAS 响应信息 System.out.println("CAS Response - " + casresp); // 输出值 System.out.println("runoob value in cache - " + mcc.get("runoob")); // 关闭连接 mcc.shutdown(); }catch(Exception ex) { System.out.println(ex.getMessage()); } } } |
get 操作实例
MemcachedJava.java 文件: