java b2b2c電子商務 springcloud分散式微服務－Session共享

通常情況下，Tomcat、Jetty等Servlet容器，會預設將Session儲存在記憶體中。如果是單個伺服器例項的應用，將Session儲存在伺服器記憶體中是一個非常好的方案。但是這種方案有一個缺點，就是不利於擴充套件。目前越來越多的應用採用分散式部署，用於實現高可用性和負載均衡等。那麼問題來了，如果將同一個應用部署在多個伺服器上透過負載均衡對外提供訪問，如何實現Session共享?實現Session共享的方案很多，其中一種常用的就是使用Tomcat、Jetty等伺服器提供的Session共享功能，將Session的內容統一儲存在一個資料庫（如MySQL）或快取（如Redis）中。瞭解springcloud架構可以加求求：三五三六二四七二五九.

下面我們將在springcloud微服務專案中，使用redis實現簡單高效的session共享。

新建一個spring boot專案，命名springcloud-session-redis

POM依賴配置

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="
    xmlns:xsi="
    xsi:schemaLocation="
    <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>

配置檔案
在application.yml中加入redis、eureka、port等配置， 需要JAVA Spring Cloud大型企業分散式微服務

雲構建的B2B2C電子商務平臺原始碼：三五三六二四七二五九．

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: 
management: 
  endpoints:
    web:
      exposure: 
        include: "*"
      cors:
        allowed-origins: "*"
        allowed-methods: "*"

Redis Session配置類

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 {
}

控制層Controller中新增測試方法

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("訪問埠：" + request.getServerPort());
        return username;
    }
}