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Spring Boot高级教程之使用Redis实现session共享

程序员文章站 2024-02-17 09:37:16
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...

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 bootjedis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redisconnectionfactorystringredistemplate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类

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 bootserver.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。

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。