Redis-nosql数据库

其他 2019-03-12 16:28:22 阅读次数: 0

一、安装

先安装gcc工具（gcc是linux下的一个编译器，可以用来编译c、c++等代码）：

yum -y install gcc     //-y表示自动安装
wget http://download.redis.io/releases/redis-2.8.17.tar.gz      //下载redis安装包（下
载到usr/local）
tar xzf redis-2.8.17.tar.gz
cd redis-2.8.17     //进入redis安装包下
make（make MALLOC=libc）    //编译命令
src/redis-server    //启动服务器
src/redis-cli       //启动客户端

二、数据类型

String、hash、list、set、zset

三、存储字符串

set key value
get key
可以设置失效时间
set key value EX 10 //10秒钟之后失效

四、存储哈希值

//hmset是存储hash值的指令，
//user是当前hash的key
//name "zhangsan" age 23 sex "nan" 是 key对应的值
127.0.0.1:6379> hmset user name "zhangsan" age 23 sex "nan"
OK
//hmget获取hash中的某一个属性的值
127.0.0.1:6379> hmget user name
1) "zhangsan"
127.0.0.1:6379> hmget user age
1) "23"
//hgetall是获取hash中的所有属性对应的值
127.0.0.1:6379> hgetall user
1) "name"
2) "zhangsan"
3) "age"
4) "23"
5) "sex"
6) "nan"

五、存储List有序列表

//lpush用来存储一个列表的命令。interesting是列表的名称，"basketball"列表中的值
127.0.0.1:6379> lpush interesting "basketball"
(integer) 1
127.0.0.1:6379> lpush interesting "football" "ball"
(integer) 3
//lrange输出列表中的数据的命令， interesting就是列表的名称 。 0 2是列表的开始输出索引和结
束索引。
127.0.0.1:6379> lrange interesting 0 2
1) "ball"
2) "football"
3) "basketball"

六、存储Set集合（无序集合）

sadd key member //存数据
smembers key //取数据
案例：
127.0.0.1:6379> sadd strset "a" "b" "c"
(integer) 3
127.0.0.1:6379> smembers strset
1) "b"
2) "c"
3) "a"

七、存储zset集合（有序集合）

zadd key score member （score是一个数字，zset就是通过这个数字进行排序，可以重复）
ZRANGEBYSCORE key 0 1000 //通过分数排序输出
有序集合是按照score进行排序

八、安全配置

config set requirepass 123456 //配置redis的密码
config get requirepass //查看密码
验证密码：auth 123456
带密码登录：./redis-cli -h 127.0.0.1 -p 6379 -a 123456 // -h表示主机IP，-p端
口，-a密码
永久密码设置：
修改redis安装目录下的redis.conf文件中的requirepass属性，比如：
requirepass 123456
修改完成之后保存退出，让配置生效的启动redis的命令如下：
./src/redis-server redis.conf

九、秒杀活动

1、导包：

 <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.40</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.4.6</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>1.3.2</version>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>5.0.4.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>5.0.4.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>5.0.4.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>
    <dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.3.3</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aspects</artifactId>
      <version>4.3.18.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>com.mchange</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.5.2</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis.caches</groupId>
      <artifactId>mybatis-ehcache</artifactId>
      <version>1.1.0</version>
    </dependency>
    <dependency>
      <groupId>org.apache.shiro</groupId>
      <artifactId>shiro-core</artifactId>
      <version>1.4.0</version>
    </dependency>
    <dependency>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
      <version>1.2</version>
    </dependency>
    <dependency>
      <groupId>org.apache.shiro</groupId>
      <artifactId>shiro-web</artifactId>
      <version>1.4.0</version>
    </dependency>
    <dependency>
      <groupId>org.apache.shiro</groupId>
      <artifactId>shiro-spring</artifactId>
      <version>1.4.0</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-core</artifactId>
      <version>2.5.4</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.9.4</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-core</artifactId>
      <version>2.9.4</version>
    </dependency>


    <!-- https://mvnrepository.com/artifact/org.springframework/spring-aspects -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aspects</artifactId>
      <version>5.0.4.RELEASE</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework.data/spring-data-redis -->
    <dependency>
      <groupId>org.springframework.data</groupId>
      <artifactId>spring-data-redis</artifactId>
      <version>2.0.5.RELEASE</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/redis.clients/jedis -->
    <dependency>
      <groupId>redis.clients</groupId>
      <artifactId>jedis</artifactId>
      <version>2.9.0</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-pool2 -->
    <dependency>
      <groupId>org.apache.commons</groupId>
      <artifactId>commons-pool2</artifactId>
      <version>2.5.0</version>
    </dependency>
  </dependencies>

2、秒杀：

public String transaction(String id){
        String msg = "";
        List<Object> list = redisTemplate.execute(new SessionCallback<List<Object>>() {
            @Override
            public List<Object> execute(RedisOperations operations) throws DataAccessException {
                //加锁
                operations.watch(id);
                Integer goods_num = (Integer) operations.boundValueOps(id).get();
                //开启事务
                operations.multi();
                if(goods_num > 0) {
                    operations.boundValueOps(id).set(goods_num-1);
                }
                return operations.exec();//自动释放锁
            }
        });

        if (list==null || list.isEmpty()) {
            msg ="已抢光";
            System.out.println(Thread.currentThread().getName() + ":失败");
        } else {
            msg ="购买成功";
            System.out.println(Thread.currentThread().getName() + ":"+list.get(0));
        }
        return msg;
    }

3、缓存穿透：

 public String demo(){
        //查询数据之前先查询缓存
        BoundListOperations<String, String> listOperations = redisTemplate.boundListOps("roles");
        Long size = listOperations.size();
        //1、查询缓存
        List<String> roles = redisTemplate.boundListOps("roles").range(0, size);
        //2、判断缓存中是否存在需要的数据
        if (roles == null || roles.isEmpty()) {
            //避免缓存穿透，所以加锁，排队访问
            System.out.println("---排队----");
            synchronized (this) {
                //双重缓存检测机制
                roles = redisTemplate.boundListOps(ApplicationConstant.REDIS.KEY_ROLES).range(0, size);
                if (roles == null || roles.isEmpty()) {
                    System.out.println("---------------");
                    //不存在，则查询数据库
                    roles = rolesDAO.queryRolesByUsername("001");
                    //数据库中的数据查到之后，再写入缓存，方便下次查询的时候直接从缓冲中取数据
                    //1、此处不论数据库查询出来的数据是否为空，都写入缓存，避免故意使用无效数据进行恶意攻击导致穿透
                    //如果上一条不停再缓存中存储无效key，会导致缓存不断增加，从而内存耗尽。导致正常数据无处安身。
                    if (roles == null || roles.isEmpty()) {
                        //如果数据库没有此数据，则先存入数据库，然后设置过期时间
                        redisTemplate.boundValueOps(ApplicationConstant.REDIS.KEY_ROLES).set("",5,TimeUnit.SECONDS);
                    } else {
                        redisTemplate.opsForList().leftPushAll(ApplicationConstant.REDIS.KEY_ROLES, roles);
                    }
                }
            }
        } else {
            System.out.println(">>>>>>>>>>>>>>>>>>>");
        }
        return "redis";
    }

4、展示热销商品：

 public List<Goods> showHotGoods(){
        Map<Goods,Integer> goods = redisTemplate.opsForHash().entries("hotGoods");
        if(goods.isEmpty()){
            Map<Goods,Integer> goodsIntegerMap = new HashMap<>();
            List<ShoppingCartBean> hotGoods = goodsDAO.findHotGoods();
            for (ShoppingCartBean cartBean : hotGoods) {
                Goods goods1 = goodsDAO.findByGoodsId(cartBean.getGoodId());
                goodsIntegerMap.put(goods1,cartBean.getGoodCount());
            }
            redisTemplate.opsForHash().putAll("hotGoods",goodsIntegerMap);
        }
        List<Goods> hotGoodsList = new ArrayList<>();
        Map<Goods,Integer> hotGoods = redisTemplate.opsForHash().entries("hotGoods");
        for (Goods o : hotGoods.keySet()) {
            hotGoodsList.add(o);
        }
        return hotGoodsList;
    }

5、服务器启动时构建缓存：

public class RedisInitListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent servletContextEvent) {
        System.out.println("#############初始化缓存##############");
        ServletContext servletContext = servletContextEvent.getServletContext();
        WebApplicationContext applicationContext = WebApplicationContextUtils.getWebApplicationContext(servletContext);
        AdminDAO adminDAO = (AdminDAO) applicationContext.getBean("adminDAO");
        AdmireDAO admireDAO = (AdmireDAO) applicationContext.getBean("admireDAO");
        RedisTemplate<String,String> redisTemplate = (RedisTemplate<String, String>) applicationContext.getBean("redisTemplate");


        List<Admins> adminIdList = adminDAO.findAllAdminId();
        //创建所有登录用户的点赞信息的缓存
        for (Admins admins : adminIdList) {
            //当前用户给谁点过赞
            List<Admire> likesById = admireDAO.findLikesById(admins.getId());
            BoundSetOperations<String, String> setOps = redisTemplate.boundSetOps(admins.getUsername());
            for (Admire admire : likesById) {
                setOps.add(admire.getTruename());
            }
        }

        //所有女孩的信息的缓存
        BoundSetOperations<String, String> setOps = redisTemplate.boundSetOps("allAdmireKey");
        List<Admire> admireList = admireDAO.findAll();
        System.out.println("======================"+admireList);
        for (Admire admire : admireList) {
            BoundHashOperations<String, Object, Object> operations = redisTemplate.boundHashOps(admire.getTruename());
            operations.put("admireId",admire.getAdmireId());
            operations.put("truename",admire.getTruename());
            operations.put("sex",admire.getSex());
            operations.put("birth",admire.getBirth());
            operations.put("job",admire.getJob());
            operations.put("marital",admire.getMarital());
            operations.put("likes",admire.getLikes());
            operations.put("pic",admire.getPic());
            setOps.add(admire.getTruename());
        }
    }
    @Override
    public void contextDestroyed(ServletContextEvent servletContextEvent) {
    }
}

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