Spring Boot系列(七)Spring Boot使用Redis实现session共享

Spring Boot系列(七)Spring Boot使用Redis实现session共享

这一篇介绍Spring Boot使用Redis实现session共享,需要springboot实战完整视频教程的,点击这里!

Redis是一个缓存消息中间件及具有丰富特性的键值存储系统。Spring Boot为Jedis客户端库和由Spring Data Redis提供的基于Jedis客户端的抽象提供自动配置spring-boot-starter-redis’Starter POM’为收集依赖提供一种便利的方式。

引入spring-boot-starter-redis,在pom.xml配置文件中增加配置如下(基于之前章节“Spring Boot 构建框架”中的pom.xml文件):

<dependency>  
    <groupId>org.springframework.boot</groupId>  
    <artifactId>spring-boot-starter-redis</artifactId>  
</dependency>

可以注入一个自动配置的RedisConnectionFactory,StringRedisTemplate或普通的跟其他Spring Bean相同的RedisTemplate实例。默认情况下,这个实例将尝试使用localhost:6379连接Redis服务器

@Component
public class MyBean {
    private StringRedisTemplate template;
    
    @Autowired
    public MyBean(StringRedisTemplate template) {
        this.template = template;
    }
    // ...
}

如果添加一个自己的任何自动配置类型的@Bean,它将替换默认的(除了RedisTemplate的情况,它是根据bean的名称’redisTemplate’而不是它的类型进行排除的)。如果在classpath路径下存在commons-pool2,默认会获得一个连接池工厂。

应用使用Redis案例

添加配置文件,配置内容如下:

# REDIS (RedisProperties)
# Redis服务器地址
spring.redis.host=192.168.0.58
# Redis服务器连接端口
spring.redis.port=6379  
# 连接超时时间(毫秒)
spring.redis.timeout=0

redis配置类,具体代码如下:

import org.springframework.boot.context.properties.ConfigurationProperties;  
import org.springframework.stereotype.Component;  
  
@Component  
@ConfigurationProperties(prefix = "spring.redis")  
public class RedisConn {  
      
    private String host;  
      
    private int port;  
      
    private int timeout;  
  
  
    public String getHost() {  
        return host;  
    }  
  
    public void setHost(String host) {  
        this.host = host;  
    }  
  
    public int getPort() {  
        return port;  
    }  
  
    public void setPort(int port) {  
        this.port = port;  
    }  
  
    public int getTimeout() {  
        return timeout;  
    }  
  
    public void setTimeout(int timeout) {  
        this.timeout = timeout;  
    }  
  
    @Override  
    public String toString() {  
        return "Redis [localhost=" + host + ", port=" + port + ", timeout=" + timeout + "]";  
    }  
      
  
}

注意:在RedisConn类中注解@ConfigurationProperties(prefix = "spring.Redis")的作用是读取springboot的默认配置文件信息中以spring.redis开头的信息。

配置cache

import java.lang.reflect.Method;  
import java.util.HashMap;  
import java.util.Map;  
 
import org.springframework.beans.factory.annotation.Autowired;  
import org.springframework.beans.factory.annotation.Value;  
import org.springframework.cache.CacheManager;  
import org.springframework.cache.annotation.CachingConfigurerSupport;  
import org.springframework.cache.annotation.EnableCaching;  
import org.springframework.cache.interceptor.KeyGenerator;  
import org.springframework.context.annotation.Bean;  
import org.springframework.context.annotation.ComponentScan;  
import org.springframework.context.annotation.Configuration;  
import org.springframework.context.annotation.PropertySource;  
import org.springframework.data.redis.cache.RedisCacheManager;  
import org.springframework.data.redis.connection.RedisConnectionFactory;  
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;  
import org.springframework.data.redis.core.RedisTemplate;  
import org.springframework.data.redis.core.StringRedisTemplate;  
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;  
import org.springframework.stereotype.Component;  
 
import com.cachemodle.RedisConn;  
import com.fasterxml.jackson.annotation.JsonAutoDetect;  
import com.fasterxml.jackson.annotation.PropertyAccessor;  
import com.fasterxml.jackson.databind.ObjectMapper;  
 
/** 
*  
* @author sandsa redis cache service 
* 
*/  
 
@Configuration  
@EnableCaching  
public class RedisConfig extends CachingConfigurerSupport {  
 
   @Autowired  
   private RedisConn redisConn;  
     
   /** 
    * 生产key的策略 
    *  
    * @return 
    */  
 
   @Bean  
   @Override  
   public KeyGenerator keyGenerator() {  
       return new KeyGenerator() {  
 
           @Override  
           public Object generate(Object target, Method method, Object... params) {  
               StringBuilder sb = new StringBuilder();  
               sb.append(target.getClass().getName());  
               sb.append(method.getName());  
               for (Object obj : params) {  
                   sb.append(obj.toString());  
               }  
               return sb.toString();  
           }  
       };  
 
   }  
 
   /** 
    * 管理缓存 
    *  
    * @param redisTemplate 
    * @return 
    */  
 
   @SuppressWarnings("rawtypes")  
   @Bean  
   public CacheManager CacheManager(RedisTemplate redisTemplate) {  
       RedisCacheManager rcm = new RedisCacheManager(redisTemplate);  
       // 设置cache过期时间,时间单位是秒  
       rcm.setDefaultExpiration(60);  
       Map<String, Long> map = new HashMap<String, Long>();  
       map.put("test", 60L);  
       rcm.setExpires(map);  
       return rcm;  
   }  
     
   /** 
    * redis 数据库连接池 
    * @return 
    */  
 
   @Bean  
   public JedisConnectionFactory redisConnectionFactory() {  
       JedisConnectionFactory factory = new JedisConnectionFactory();  
       factory.setHostName(redisConn.getHost());  
       factory.setPort(redisConn.getPort());  
       factory.setTimeout(redisConn.getTimeout()); // 设置连接超时时间  
       return factory;  
   }  
 
   /** 
    * redisTemplate配置 
    *  
    * @param factory 
    * @return 
    */  
   @SuppressWarnings({ "rawtypes", "unchecked" })  
   @Bean  
   public RedisTemplate<String, String> redisTemplate(RedisConnectionFactory factory) {  
       StringRedisTemplate template = new StringRedisTemplate(factory);  
       Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);  
       ObjectMapper om = new ObjectMapper();  
       om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);  
       om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);  
       jackson2JsonRedisSerializer.setObjectMapper(om);  
       template.setValueSerializer(jackson2JsonRedisSerializer);  
       template.afterPropertiesSet();  
       return template;  
   }  
 
}

分析:缓存类继承的是CachingConfigurerSupport,它把读取的配置文件信息的RedisConn类对象注入到这个类中。在这个类中keyGenerator()方法是key的生成策略,CacheManager()方法是缓存管理策略,redisConnectionFactory()是redis连接,redisTemplate()方法是redisTemplate配置信息,配置后使redis中能存储Java对象。

测试配置是否成功,实例:

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(Application.class)
public class TestRedis {
    @Autowired
    private StringRedisTemplate stringRedisTemplate; // 处理字符串
    
    @Autowired
    private RedisTemplate redisTemplate; // 处理对象
    @Test
    public void test() throws Exception {
        stringRedisTemplate.opsForValue().set("yoodb", "123");
        Assert.assertEquals("123", stringRedisTemplate.opsForValue().get("yoodb"));
    }
}

简单封装的Redis工具类,代码如下:

import java.io.Serializable;  
import java.util.Set;  
import java.util.concurrent.TimeUnit;  
  
import org.springframework.beans.factory.annotation.Autowired;  
import org.springframework.data.redis.core.RedisTemplate;  
import org.springframework.data.redis.core.ValueOperations;  
import org.springframework.stereotype.Component;  
  
@Component  
public class RedisUtils {  
  
    @SuppressWarnings("rawtypes")  
    @Autowired  
    private RedisTemplate redisTemplate;  
  
    /** 
     * 批量删除对应的value 
     *  
     * @param keys 
     */  
    public void remove(final String... keys) {  
        for (String key : keys) {  
            remove(key);  
        }  
    }  
  
    /** 
     * 批量删除key 
     *  
     * @param pattern 
     */  
    @SuppressWarnings("unchecked")  
    public void removePattern(final String pattern) {  
        Set<Serializable> keys = redisTemplate.keys(pattern);  
        if (keys.size() > 0)  
            redisTemplate.delete(keys);  
    }  
  
    /** 
     * 删除对应的value 
     *  
     * @param key 
     */  
    @SuppressWarnings("unchecked")  
    public void remove(final String key) {  
        if (exists(key)) {  
            redisTemplate.delete(key);  
        }  
    }  
  
    /** 
     * 判断缓存中是否有对应的value 
     *  
     * @param key 
     * @return 
     */  
    @SuppressWarnings("unchecked")  
    public boolean exists(final String key) {  
        return redisTemplate.hasKey(key);  
    }  
  
    /** 
     * 读取缓存 
     *  
     * @param key 
     * @return 
     */  
    @SuppressWarnings("unchecked")  
    public Object get(final String key) {  
        Object result = null;  
        ValueOperations<Serializable, Object> operations = redisTemplate.opsForValue();  
        result = operations.get(key);  
        return result;  
    }  
  
    /** 
     * 写入缓存 
     *  
     * @param key 
     * @param value 
     * @return 
     */  
    @SuppressWarnings("unchecked")  
    public boolean set(final String key, Object value) {  
        boolean result = false;  
        try {  
            ValueOperations<Serializable, Object> operations = redisTemplate.opsForValue();  
            operations.set(key, value);  
            result = true;  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
        return result;  
    }  
  
    /** 
     * 写入缓存 
     *  
     * @param key 
     * @param value 
     * @return 
     */  
    @SuppressWarnings("unchecked")  
    public boolean set(final String key, Object value, Long expireTime) {  
        boolean result = false;  
        try {  
            ValueOperations<Serializable, Object> operations = redisTemplate.opsForValue();  
            operations.set(key, value);  
            redisTemplate.expire(key, expireTime, TimeUnit.SECONDS);  
            result = true;  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
        return result;  
    }  
  
}

查询数据库时自动使用缓存,根据方法生成缓存,参考代码如下:

@Service
public class UserService {
  @Cacheable(value = "redis-key")
  public UserInfo getUserInfo(Long id, String sex, int age, String name) {
      System.out.println("无缓存时调用----数据库查询");
      return new UserInfo(id, sex, age, name);
  }
}

注意:value的值就是缓存到redis中的key,此key是需要自己在进行增加缓存信息时定义的key,用于标识唯一性的。

Session 共享

分布式系统中session共享有很多不错的解决方案,其中托管到缓存中是比较常见的方案之一,下面利用Session-spring-session-data-redis实现session共享。

引入依赖,在pom.xml配置文件中增加如下内容:

<dependency>
    <groupId>org.springframework.session</groupId>
    <artifactId>spring-session-data-redis</artifactId>
</dependency>

Session配置,具体代码如下:

@Configuration
@EnableRedisHttpSession(maxInactiveIntervalInSeconds = 86400*30)
public class SessionConfig {
}

maxInactiveIntervalInSeconds: 设置Session失效时间,使用Redis Session之后,原Spring Boot的server.session.timeout属性不再生效。

测试实例,具体代码如下:

@RequestMapping("uid")
String uid(HttpSession session) {
UUID uid = (UUID) session.getAttribute("uid");
if (uid == null) {
uid = UUID.randomUUID();
}
session.setAttribute("uid", uid);
return session.getId();
}

登录redis服务端,输入命令keys ‘session*’,查看缓存是否成功。

来源: 素文宅博客

链接: https://blog. yood b.com/yoodb/article/detail/1412

原文 

https://mp.weixin.qq.com/s?__biz=MzI4Njc5NjM1NQ==&mid=2247484135&idx=2&sn=187759bac503e75fde0c520b75508ae5&chksm=ebd63dcbdca1b4dda788fcae43c8579bb7f3e7cdb60edbea9d9725dec91dbfa54c07c4915221#rd

PS:如果您想和业内技术大牛交流的话,请加qq群(527933790)或者关注微信公众 号(AskHarries),谢谢!

转载请注明原文出处:Harries Blog™ » Spring Boot系列(七)Spring Boot使用Redis实现session共享

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