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

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 /> <!-- lookup parent from repository -->
    </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:[email protected]:8761/eureka/
management:
  endpoints:
    web:
      exposure:
        include: "*"
      cors:
        allowed-origins: "*"
        allowed-methods: "*"

Redis Session配置类
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;
    }
}

原文地址：https://blog.51cto.com/14622290/2466800