java秒杀之redis限流操作
四颗石头 人气:0最近写到了一个秒杀的功能模块，为了保证高并发情况下不会宕机，要从多方面去考虑，当前的限流操作只是其中的一个方面，具体操作如下。
导入所需依赖
<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>
编写注解
@Retention(RUNTIME)//运行时有效
@Target(ElementType.METHOD)//用在方法上
public @interface AccessLimit {
int seconds();//时间范围(单位:秒)
int maxCount();//在这个时间范围内最大访问次数
}
编写拦截器
public class AcessLimiitInterceptor implements HandlerInterceptor {
//注入redisTemplate
@Autowired
private RedisTemplate<String,String> redisTemplate;
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
//设置redisTemplate的序列化方式(必须设置为这种方式，因为要用到incr)
redisTemplate.setKeySerializer(new StringRedisSerializer());
redisTemplate.setValueSerializer(new StringRedisSerializer());
if(handler instanceof HandlerMethod){
//查看该方法上是否有@AcessLimit注解
HandlerMethod hm= (HandlerMethod) handler;
AccessLimit accessLimit=hm.getMethodAnnotation(AccessLimit.class);
//没有@AcessLimit注解，证明无限流操作，直接放行
if(accessLimit==null){
return true;
}
//获取注解的参数值
int seconds=accessLimit.seconds();//时间范围
int maxCount=accessLimit.maxCount();//时间范围内的最大访问次数
//该请求的路径
String key=request.getRequestURI();
//在该时间范围内已经访问的次数
String countStr=redisTemplate.opsForValue().get(key);
Integer count=null;
//如果不是第一次访问，则把访问次数转换为integer类型
if(countStr!=null){
count= Integer.valueOf(redisTemplate.opsForValue().get(key));
}
//拿到访问次数的过期时间
Long keySeconds=redisTemplate.getExpire(key);
//该时间范围内没有访问
if(count==null){
//第一次访问，设置key为访问路径，值为访问次数1
redisTemplate.opsForValue().set(key,1+"");
//设置过期时间
redisTemplate.expire(key,600, TimeUnit.SECONDS);
}else if(count<maxCount){//在该时间范围内已经有访问记录，但访问没有达到最大次数
//访问次数+1
redisTemplate.opsForValue().increment(key,1);
//设置剩余过期时间(修改完该key的value值后，对应的过期时间会失效，需重新设置)
redisTemplate.expire(key,keySeconds, TimeUnit.SECONDS);
}else{//在该时间范围内已经超过最大的访问次数
return false;
}
}
//放行
return true;
}
}
编写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">
<!--开启注解的扫描，希望处理service和dao，controller不需要Spring框架去处理-->
<context:component-scan base-package="cn.itcast" >
<!--配置哪些注解不扫描-->
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" />
</context:component-scan>
<!--Spring整合MyBatis框架-->
<!--配置连接池-->
<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工厂-->
<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框架声明式事务管理-->
<!--配置事务管理器-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
<!--配置事务通知-->
<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增强-->
<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 相关配置 -->
<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的监听器，默认只加载WEB-INF目录下的applicationContext.xml配置文件-->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!--设置配置文件的路径-->
<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>
<!--加载springmvc.xml配置文件-->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
<!--启动服务器，创建该servlet-->
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<!--解决中文乱码的过滤器-->
<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>
注解应用
@AccessLimit(seconds = 500,maxCount = 3)
@RequestMapping(value = "/findAll")
public String findAll(Model model){
System.out.println("csl");
return "list";
}
总 结
以上操作就完成了java后台使用redisTemplate的限流操作，这里还需各位自己开启一个redis服务端并且把配置文件中的地址改成对应的ip，希望以上内容对大家有帮助，多提宝贵意见。
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