java秒殺之redis限流操作詳解
最近寫到瞭一個秒殺的功能模塊,為瞭保證高並發情況下不會宕機,要從多方面去考慮,當前的限流操作隻是其中的一個方面,具體操作如下。
導入所需依賴
<properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> <spring.version>5.0.2.RELEASE</spring.version> <slf4j.version>1.6.6</slf4j.version> <log4j.version>1.2.12</log4j.version> <mysql.version>5.1.6</mysql.version> <mybatis.version>3.4.5</mybatis.version> </properties> <dependencies> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.6.8</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>compile</scope> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> <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>2.0</version> <scope>provided</scope> </dependency> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <!-- log start --> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>${log4j.version}</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>${slf4j.version}</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>${slf4j.version}</version> </dependency> <!-- log end --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>${mybatis.version}</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.3.0</version> </dependency> <dependency> <groupId>c3p0</groupId> <artifactId>c3p0</artifactId> <version>0.9.1.2</version> <type>jar</type> <scope>compile</scope> </dependency> <dependency> <groupId>org.springframework.data</groupId> <artifactId>spring-data-redis</artifactId> <version>1.7.2.RELEASE</version> </dependency> <dependency> <groupId>redis.clients</groupId> <artifactId>jedis</artifactId> <version>2.8.1</version> </dependency> </dependencies>
編寫註解
@Retention(RUNTIME)//運行時有效 @Target(ElementType.METHOD)//用在方法上 public @interface AccessLimit { int seconds();//時間范圍(單位:秒) int maxCount();//在這個時間范圍內最大訪問次數 }
編寫攔截器
public class AcessLimiitInterceptor implements HandlerInterceptor { //註入redisTemplate @Autowired private RedisTemplate<String,String> redisTemplate; @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) { //設置redisTemplate的序列化方式(必須設置為這種方式,因為要用到incr) redisTemplate.setKeySerializer(new StringRedisSerializer()); redisTemplate.setValueSerializer(new StringRedisSerializer()); if(handler instanceof HandlerMethod){ //查看該方法上是否有@AcessLimit註解 HandlerMethod hm= (HandlerMethod) handler; AccessLimit accessLimit=hm.getMethodAnnotation(AccessLimit.class); //沒有@AcessLimit註解,證明無限流操作,直接放行 if(accessLimit==null){ return true; } //獲取註解的參數值 int seconds=accessLimit.seconds();//時間范圍 int maxCount=accessLimit.maxCount();//時間范圍內的最大訪問次數 //該請求的路徑 String key=request.getRequestURI(); //在該時間范圍內已經訪問的次數 String countStr=redisTemplate.opsForValue().get(key); Integer count=null; //如果不是第一次訪問,則把訪問次數轉換為integer類型 if(countStr!=null){ count= Integer.valueOf(redisTemplate.opsForValue().get(key)); } //拿到訪問次數的過期時間 Long keySeconds=redisTemplate.getExpire(key); //該時間范圍內沒有訪問 if(count==null){ //第一次訪問,設置key為訪問路徑,值為訪問次數1 redisTemplate.opsForValue().set(key,1+""); //設置過期時間 redisTemplate.expire(key,600, TimeUnit.SECONDS); }else if(count<maxCount){//在該時間范圍內已經有訪問記錄,但訪問沒有達到最大次數 //訪問次數+1 redisTemplate.opsForValue().increment(key,1); //設置剩餘過期時間(修改完該key的value值後,對應的過期時間會失效,需重新設置) redisTemplate.expire(key,keySeconds, TimeUnit.SECONDS); }else{//在該時間范圍內已經超過最大的訪問次數 return false; } } //放行 return true; } }
編寫application.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd"> <!--開啟註解的掃描,希望處理service和dao,controller不需要Spring框架去處理--> <context:component-scan base-package="cn.itcast" > <!--配置哪些註解不掃描--> <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" /> </context:component-scan> <!--Spring整合MyBatis框架--> <!--配置連接池--> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="com.mysql.jdbc.Driver"/> <property name="jdbcUrl" value="jdbc:mysql:///ssm"/> <property name="user" value="root"/> <property name="password" value="root"/> </bean> <!--配置SqlSessionFactory工廠--> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> </bean> <!--配置AccountDao接口所在包--> <bean id="mapperScanner" class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="cn.itcast.dao"/> </bean> <!--配置Spring框架聲明式事務管理--> <!--配置事務管理器--> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource" /> </bean> <!--配置事務通知--> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <tx:attributes> <tx:method name="find*" read-only="true"/> <tx:method name="*" isolation="DEFAULT"/> </tx:attributes> </tx:advice> <!--配置AOP增強--> <aop:config> <aop:advisor advice-ref="txAdvice" pointcut="execution(* cn.itcast.service.impl.*ServiceImpl.*(..))"/> </aop:config> <context:property-placeholder location="classpath*:*.properties"></context:property-placeholder> <!-- <context:property-placeholder location="classpath*:properties/*.properties" /> --> <!-- redis 相關配置 --> <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig"> <property name="maxIdle" value="${redis.maxIdle}" /> <property name="maxWaitMillis" value="${redis.maxWait}" /> <property name="testOnBorrow" value="${redis.testOnBorrow}" /> </bean> <bean id="JedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory" p:host-name="${redis.host}" p:port="${redis.port}" p:password="${redis.pass}" p:pool-config-ref="poolConfig"/> <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate"> <property name="connectionFactory" ref="JedisConnectionFactory" /> </bean> </beans>
配置web.xml
<web-app> <display-name>Archetype Created Web Application</display-name> <!--配置Spring的監聽器,默認隻加載WEB-INF目錄下的applicationContext.xml配置文件--> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!--設置配置文件的路徑--> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:applicationContext.xml</param-value> </context-param> <!--配置前端控制器--> <servlet> <servlet-name>dispatcherServlet</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!--加載springmvc.xml配置文件--> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc.xml</param-value> </init-param> <!--啟動服務器,創建該servlet--> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dispatcherServlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!--解決中文亂碼的過濾器--> <filter> <filter-name>characterEncodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>characterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>
註解應用
@AccessLimit(seconds = 500,maxCount = 3) @RequestMapping(value = "/findAll") public String findAll(Model model){ System.out.println("csl"); return "list"; }
總 結
以上操作就完成瞭java後臺使用redisTemplate的限流操作,這裡還需各位自己開啟一個redis服務端並且把配置文件中的地址改成對應的ip,希望以上內容對大傢有幫助,多提寶貴意見。
以上就是本文的全部內容,希望對大傢的學習有所幫助,也希望大傢多多支持WalkonNet。
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