java b2b2c电子商务 springcloud分布式微服务-Session共享

小鱼儿 2021-06-22 15:36 433阅读 0赞

通常情况下，Tomcat、Jetty等Servlet容器，会默认将Session保存在内存中。如果是单个服务器实例的应用，将Session保存在服务器内存中是一个非常好的方案。但是这种方案有一个缺点，就是不利于扩展。目前越来越多的应用采用分布式部署，用于实现高可用性和负载均衡等。那么问题来了，如果将同一个应用部署在多个服务器上通过负载均衡对外提供访问，如何实现Session共享?实现Session共享的方案很多，其中一种常用的就是使用Tomcat、Jetty等服务器提供的Session共享功能，将Session的内容统一存储在一个数据库（如MySQL）或缓存（如Redis）中。了解springcloud架构可以加求求：三五三六二四七二五九.  
下面我们将在springcloud微服务项目中，使用redis实现简单高效的session共享。  
新建一个spring boot项目，命名springcloud-session-redis  
POM依赖配置

<?xml version="1.0" encoding="UTF-8"?>
    <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>com.carry</groupId>
        <artifactId>springcloud-session-redis</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <packaging>jar</packaging>
    
        <name>springcloud-session-redis</name>
        <description>Demo project for Spring Boot</description>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.0.4.RELEASE</version>
            <relativePath /> 
        </parent>
    
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
            <spring-cloud.version>Finchley.SR1</spring-cloud.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-redis</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.session</groupId>
                <artifactId>spring-session-data-redis</artifactId>
            </dependency>
            <dependency>
                <groupId>org.apache.commons</groupId>
                <artifactId>commons-pool2</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-actuator</artifactId>
            </dependency>
    
        </dependencies>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>${spring-cloud.version}</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    
    </project>

配置文件  
在application.yml中加入redis、eureka、port等配置

server:
      port: 8090
    spring:
      application:
        name: service-session-redis
      redis:
        host: 192.168.68.100
        port: 6379
        password: 123456
        timeout: 6000ms
        lettuce:
          pool:
            max-active: 8
            max-wait: -1ms
            max-idle: 8
            min-idle: 0
        database: 0
    eureka:
      client:
        serviceUrl:
          defaultZone: http://admin:123456@localhost:8761/eureka/
    management: 
      endpoints:
        web:
          exposure: 
            include: "*"
          cors:
            allowed-origins: "*"
            allowed-methods: "*"

Redis Session配置类

package com.carry.config;
    
    import org.springframework.context.annotation.Configuration;
    import org.springframework.session.data.redis.config.annotation.web.http.EnableRedisHttpSession;
    
    @Configuration
    @EnableRedisHttpSession
    public class RedisSessionConfig {
    
    }

控制层Controller中添加测试方法

package com.carry.controller;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpSession;
    
    import org.springframework.cloud.context.config.annotation.RefreshScope;
    import org.springframework.util.StringUtils;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    @RefreshScope
    public class UserManagementController {
    
        /** * redis sesion共享 * * @param request * @return */
        @GetMapping("/getUser")
        public String getUser(HttpServletRequest request) {
            HttpSession session = request.getSession();
            String username = (String) session.getAttribute("username");
            if (StringUtils.isEmpty(username)) {
                username = "testSessionRedis|" + System.currentTimeMillis();
                session.setAttribute("username", username);
            }
            System.out.println("访问端口：" + request.getServerPort());
            return username;
        }
    }