java秒杀之redis限流操作详解

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
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
<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>

1
2
3
4
5
6
@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
 }

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
49
50
51
52
53
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;
    }
}

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
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
<?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>

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
<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>

1
2
3
4
5
6
@AccessLimit(seconds = 500,maxCount = 3)
    @RequestMapping(value = "/findAll")
    public String findAll(Model model){
        System.out.println("csl");
        return "list";
    }