SpringBoot学习(十八)之使用Spring Session集群-redis

本是古典何须时尚 2021-11-13 23:58 202阅读 0赞

用nginx做负载的时候，会出现每一次http请求都会分配到不同的tomcat上，这样用session存储用户数据就会有问题。因为tomcat集群之间没有实现session共享。

spring-session跟redis很好的帮我们解决了这个问题。

## 一、引入maven依赖 ##

<?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.cicoding.druid</groupId>
    	<artifactId>springboot_session_redis_colony</artifactId>
    	<version>0.0.1-SNAPSHOT</version>
    	<packaging>war</packaging>
    
    	<name>springboot_session_redis_colony</name>
    	<description>Demo project for Spring Boot</description>
    
    	<parent>
    		<groupId>org.springframework.boot</groupId>
    		<artifactId>spring-boot-starter-parent</artifactId>
    		<version>1.5.9.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>
    	</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.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    	</dependencies>
    
    	<build>
    		<plugins>
    			<plugin>
    				<groupId>org.springframework.boot</groupId>
    				<artifactId>spring-boot-maven-plugin</artifactId>
    			</plugin>
    		</plugins>
    	</build>
    </project>

## 二、配置application.properties ##

server.port=8082
    spring.redis.host=localhost
    spring.redis.port=6379
    spring.redis.password=redis password
    
    # spring session使用存储类型
    spring.session.store-type=redis

*  spirngboot默认就是使用redis方式，如果不想用可以填none。

## 三、在启动类中加入@EnableRedisHttpSession  注解 ##

package com.cicoding;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cache.annotation.EnableCaching;
    import org.springframework.session.data.redis.config.annotation.web.http.EnableRedisHttpSession;
    
    @EnableCaching
    @EnableRedisHttpSession  
    @SpringBootApplication
    public class SessionApplication {
    
    	public static void main(String[] args) {
    		SpringApplication.run(SessionApplication.class, args);
    	}
    }

## 四、编写控制器 ##

package com.cicoding.controller;
    
    import java.util.HashMap;
    import java.util.Map;
    
    import javax.servlet.http.HttpServletRequest;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    @Controller
    @RequestMapping(value = "/")
    public class UserController {
    
    	@ResponseBody
        @RequestMapping(value = "/session")
        public Map<String, Object> getSession(HttpServletRequest request) {
            request.getSession().setAttribute("username", "admin");
            Map<String, Object> map = new HashMap<String, Object>();
            map.put("sessionId", request.getSession().getId());
            return map;
        }
    
        @ResponseBody
        @RequestMapping(value = "/get")
        public String get(HttpServletRequest request) {
            String userName = (String) request.getSession().getAttribute("username");
    
            return userName;
        }
    
    }

五、测试

*  先输入http://localhost:8082/session，在session中设置一个值

![20190801115603428.png][]

*  http://localhost:8082/get,获取session中的值

![20190801115622988.png][]

*  复制这个工程，application.properties中的server.port=8081，然后访问“http://localhost:8081/get”，如下获取到了另一个工程中设置的session的值。

![20190801115652488.png][]

这样两个应用就能拿到同一个session集群共享了session

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[20190801115603428.png]: /images/20211113/160b663afdfb4bda851647bfcace29d0.png
[20190801115622988.png]: /images/20211113/0a1f678057904f029c4547b6830471e9.png
[20190801115652488.png]: /images/20211113/039c9616c8de4b72aeebbecc1a5d7ab6.png