Anforderung: Es liegt ein Gebot vor (es kann als das Ergreifen roter Umschläge verstanden werden, der Kontostand beträgt vorab 1.000 Yuan), jeder kann es schnappen, und nachdem es jedem Benutzer gelungen ist, zu schnappen, wird die Gesamtzahl des letzten Benutzers angezeigt Das Gebot wird aktualisiert und im Fall der Parallelität wird die optimistische Sperre von Redis verwendet. Um die Richtigkeit des aktualisierten Gesamtgebotswerts sicherzustellen, geben Sie zunächst einen Gebotsbetrag in Redis ein:
set accountBalance "1000"
Die Implementierungsmethode lautet wie folgt:
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>mybatisPage</groupId> <artifactId>page</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <name>PageHelperSample</name> <url>http://git.oschina.net/free/Mybatis-Sample</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <!-- jstl --> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>1.1.2</version> </dependency> <dependency> <groupId>taglibs</groupId> <artifactId>standard</artifactId> <version>1.1.2</version> </dependency> <!-- jstl --> <dependency> <groupId>commons-pool</groupId> <artifactId>commons-pool</artifactId> <version>1.6</version> </dependency> <!-- log mybatis sql --> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.5</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.5</version> </dependency> <!-- log mybatis sql --> <!-- fastjson --> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.5</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.4</version> </dependency> <!-- web --> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> <scope>provided</scope> </dependency> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>taglibs</groupId> <artifactId>standard</artifactId> <version>1.1.2</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper</artifactId> <version>3.7.4</version> </dependency> <dependency> <groupId>com.github.jsqlparser</groupId> <artifactId>jsqlparser</artifactId> <version>0.9.1</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.2.5</version> </dependency> <!-- util --> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-lang3</artifactId> <version>3.1</version> </dependency> <!-- mysql --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.35</version> </dependency> <!-- redis --> <dependency> <groupId>redis.clients</groupId> <artifactId>jedis</artifactId> <version>2.1.0</version> <type>jar</type> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.6</source> <target>1.6</target> <encoding>utf-8</encoding> </configuration> </plugin> <plugin> <groupId>org.mortbay.jetty</groupId> <artifactId>jetty-maven-plugin</artifactId> <version>8.0.0.M3</version> </plugin> </plugins> </build></project>
web.xml
<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0"> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> <servlet> <servlet-name>bid</servlet-name> <servlet-class>com.heli.mybatis.page.servlet.ReidsMatchServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>bid</servlet-name> <url-pattern>/bid</url-pattern> </servlet-mapping> <servlet> <servlet-name>list</servlet-name> <servlet-class>com.heli.mybatis.page.servlet.ReidsMatchListServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>list</servlet-name> <url-pattern>/list</url-pattern> </servlet-mapping></web-app>
Servlet
package com.heli.mybatis.page.servlet; import java.io.IOException; import java.util.List; import java.util.Random; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.lang3.StringUtils; import com.commnon.RedisAPI; import redis.clients.jedis.Jedis; import redis.clients.jedis.JedisPool; import redis.clients.jedis.Transaction; public class ReidsMatchServlet extends HttpServlet { public static JedisPool pool = RedisAPI.getPool(); // RedisAPI.set("accountBalance", "999999999");// 标还剩999999999块钱 private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Jedis jedis = pool.getResource(); long start = System.currentTimeMillis(); int flag = 0; try { flag = bid(request, response, jedis); } catch (Exception e) { e.printStackTrace(); response.getWriter().write("fail buy"); } finally { pool.returnBrokenResource(jedis); RedisAPI.returnResource(pool, jedis); } if (flag == 1) { response.getWriter().write("success buy"); } else if (flag == 2) { response.getWriter().write("have buy"); } else if (flag == 0) { response.getWriter().write("bid is zero ,you can not buy"); }else{ response.getWriter().write("fail buy"); } long end = System.currentTimeMillis(); System.out.println("--------------------------------------------请求耗时:" + (end - start) + "毫秒"); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } private int bid(HttpServletRequest request, HttpServletResponse response, Jedis jedis) throws Exception { int flag = 0;// 1,成功,2已经购买,3已经没钱了,其他異常 // 每个请求对应一个userId int userId = new Random().nextInt(999999); // 观察 总标值,每人抢购一元 while ("OK".equals(jedis.watch("accountBalance"))) { // 判断是否购买过 Boolean isBuy = RedisAPI.sismember("userIdSet", userId + ""); if (isBuy) { flag = 2; return flag; } //投资额 int r = 1;// new Random().nextInt(2); int lastAccount = 0; String balance = RedisAPI.get("accountBalance"); if (StringUtils.isNotBlank(balance)) { lastAccount = Integer.valueOf(balance) - r; } if (lastAccount < 0) { flag = 3; break; } Transaction tx = jedis.multi(); tx.set("accountBalance", lastAccount + ""); List<Object> result = tx.exec(); if (result == null || result.isEmpty()) { jedis.unwatch(); } else { System.out.println("恭喜您," + userId + "已经中标" + r + "元,标余额" + lastAccount + "元"); RedisAPI.set(Thread.currentThread().getName(), r + ""); RedisAPI.sadd("userIdSet", userId + ""); flag = 1; break; } } return flag; } }
package com.heli.mybatis.page.servlet; import java.io.IOException; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Set; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.commnon.RedisAPI; import redis.clients.jedis.Jedis; import redis.clients.jedis.JedisPool; public class ReidsMatchListServlet extends HttpServlet { public static JedisPool pool= RedisAPI.getPool();; public static Jedis jedis; static { jedis = pool.getResource(); } private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { list(request, response); try { response.sendRedirect("list.jsp"); } catch (IOException e) { e.printStackTrace(); } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } private void list(HttpServletRequest request, HttpServletResponse response) { Set set = jedis.smembers("userIdSet"); Iterator ite = set.iterator(); System.out.println("中标名单-------------------------"); int i = 0; Map<String, String> map = new HashMap<String, String>(); while (ite.hasNext()) { i++; Object obj1 = ite.next(); System.out.println("第" + i + "名:" + obj1); map.put("第" + i + "名:", obj1 + ""); } request.getSession().setAttribute("user", map); System.out.println("中标名单-------------------------"); } }
Tool-Klasse
package com.commnon; import java.util.ResourceBundle; import redis.clients.jedis.Jedis; import redis.clients.jedis.JedisPool; import redis.clients.jedis.JedisPoolConfig; /** * Redis操作接口 * * @author 林计钦 * @version 1.0 2013-6-14 上午08:54:14 */ public class RedisAPI { private static JedisPool pool = null; private static ThreadLocal<JedisPool> poolThreadLocal = new ThreadLocal<JedisPool>(); /** * 构建redis连接池 * * @param ip * @param port * @return JedisPool */ public static JedisPool getPool() { if (pool == null) { ResourceBundle bundle = ResourceBundle.getBundle("redis"); if (bundle == null) { throw new IllegalArgumentException( "[redis.properties] is not found!"); } JedisPoolConfig config = new JedisPoolConfig(); config.setMaxActive(Integer.valueOf(bundle .getString("redis.pool.maxActive"))); config.setMaxIdle(Integer.valueOf(bundle .getString("redis.pool.maxIdle"))); config.setMaxWait(Long.valueOf(bundle.getString("redis.pool.maxWait"))); config.setTestOnBorrow(Boolean.valueOf(bundle .getString("redis.pool.testOnBorrow"))); config.setTestOnReturn(Boolean.valueOf(bundle .getString("redis.pool.testOnReturn"))); pool = new JedisPool(config, bundle.getString("redis.ip"), Integer.valueOf(bundle.getString("redis.port"))); } return pool; } public static JedisPool getConnection() { // ②如果poolThreadLocal没有本线程对应的JedisPool创建一个新的JedisPool,将其保存到线程本地变量中。 if (poolThreadLocal.get() == null) { pool = RedisAPI.getPool(); poolThreadLocal.set(pool); return pool; } else { return poolThreadLocal.get();// ③直接返回线程本地变量 } } /** * 返还到连接池 * * @param pool * @param redis */ public static void returnResource(JedisPool pool, Jedis redis) { if (redis != null) { pool.returnResource(redis); } } /** * 获取数据 * * @param key * @return */ public static String get(String key) { String value = null; JedisPool pool = null; Jedis jedis = null; try { pool = getPool(); jedis = pool.getResource(); value = jedis.get(key); } catch (Exception e) { e.printStackTrace(); } finally { // 释放redis对象 pool.returnBrokenResource(jedis); // 返还到连接池 returnResource(pool, jedis); } return value; } /** * 赋值数据 * * @param key * @return */ public static String set(String key, String value) { String result = null; JedisPool pool = null; Jedis jedis = null; try { pool = getPool(); jedis = pool.getResource(); result = jedis.set(key, value); } catch (Exception e) { e.printStackTrace(); } finally { // 释放redis对象 pool.returnBrokenResource(jedis); // 返还到连接池 returnResource(pool, jedis); } return result; } /** * 赋值数据 * * @param key * @return */ public static Long sadd(String key, String value) { Long result = null; JedisPool pool = null; Jedis jedis = null; try { pool = getPool(); jedis = pool.getResource(); result = jedis.sadd(key, value); } catch (Exception e) { e.printStackTrace(); } finally { // 释放redis对象 pool.returnBrokenResource(jedis); // 返还到连接池 returnResource(pool, jedis); } return result; } /** * 判断set中是否有值 * * @param key * @return */ public static Boolean sismember(String key, String member) { Boolean result = null; JedisPool pool = null; Jedis jedis = null; try { pool = getPool(); jedis = pool.getResource(); result = jedis.sismember(key, member); } catch (Exception e) { e.printStackTrace(); } finally { // 释放redis对象 pool.returnBrokenResource(jedis); // 返还到连接池 returnResource(pool, jedis); } return result; } }
redis.properties
#\u6700\u5927\u5206\u914d\u7684\u5bf9\u8c61\u6570 redis.pool.maxActive=1024 #\u6700\u5927\u80fd\u591f\u4fdd\u6301idel\u72b6\u6001\u7684\u5bf9\u8c61\u6570 redis.pool.maxIdle=200 #\u5f53\u6c60\u5185\u6ca1\u6709\u8fd4\u56de\u5bf9\u8c61\u65f6\uff0c\u6700\u5927\u7b49\u5f85\u65f6\u95f4 redis.pool.maxWait=1000 #\u5f53\u8c03\u7528borrow Object\u65b9\u6cd5\u65f6\uff0c\u662f\u5426\u8fdb\u884c\u6709\u6548\u6027\u68c0\u67e5 redis.pool.testOnBorrow=true #\u5f53\u8c03\u7528return Object\u65b9\u6cd5\u65f6\uff0c\u662f\u5426\u8fdb\u884c\u6709\u6548\u6027\u68c0\u67e5 redis.pool.testOnReturn=true #IP redis.ip=127.0.0.1 #Port redis.port=6379
bid.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>抢标秒杀</title> <style type="text/css"> * { margin: 0; } html, body { height: 100%; } .wrapper { min-height: 100%; height: auto !important; height: 100%; margin: 0 auto -155px; } .footer, .push { height: 155px; } .middle { text-align: center; margin: 0 auto; width: 600px; height: auto; } </style> </head> <body> <form name="formBid" action="bid" method="get"> <div class="wrapper"> <div class="middle"> <h1 style="padding: 0px 0 10px;">秒标</h1> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <input type="submit" style="width: 600px; height: 200px" value="秒杀" /> <br> <br> <br> <br> <br> </div> </div> </form> <form name="formList" action="list" method="post"> <div class="wrapper"> <div class="middle"> <br> <br> <br> <br> <br> <input type="submit" style="width: 200px; height: 50px" value="查看秒杀结果" /> </div> </div> </form> </body> </html>
list.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>抢标秒杀</title> <style type="text/css"> * { margin: 0; } html, body { height: 100%; } .wrapper { min-height: 100%; height: auto !important; height: 100%; margin: 0 auto -155px; } .footer, .push { height: 155px; } .middle { text-align: center; margin: 0 auto; width: 600px; height: auto; } </style> </head> <body> <% java.util.Map<String, String> mapBean = (java.util.Map<String, String>) request.getSession() .getAttribute("user"); %> <form name="formList" action="list" method="post"> <div class="wrapper"> <div class="middle"> <br> <br> <br> <br> <br> <br> <br> <br> <h1 style="padding: 0px 0 10px;"> 中奖名单<% if (mapBean != null) { %> <%=mapBean.size()%></h1> <% } %> <br> <% if (mapBean != null) { for (String key : mapBean.keySet()) { %> <%=key%>--<%=mapBean.get(key)%><br> <% } } %> </div> </div> </form> </body> </html>