Redis入门

目录

1.五中常见数据类型

<1>String类型的操作

2.使用pringboot操作redis

3.Spring Cache整合redis简化缓存开发

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1.五中常见数据类型

<1>String类型的操作

 

 

 

2.使用pringboot操作redis

 @Autowired
    private RedisTemplate redisTemplate;

    /**
     * 操作String类型数据
     */
    @Test
    public void testString(){
        redisTemplate.opsForValue().set("city123","beijing");

        String value = (String) redisTemplate.opsForValue().get("city123");
        System.out.println(value);

        redisTemplate.opsForValue().set("key1","value1",10l, TimeUnit.SECONDS);

        Boolean aBoolean = redisTemplate.opsForValue().setIfAbsent("city1234", "nanjing");
        System.out.println(aBoolean);
    }

    /**
     * 操作Hash类型数据
     */
    @Test
    public void testHash(){
        HashOperations hashOperations = redisTemplate.opsForHash();

        //存值
        hashOperations.put("002","name","xiaoming");
        hashOperations.put("002","age","20");
        hashOperations.put("002","address","bj");

        //取值
        String age = (String) hashOperations.get("002", "age");
        System.out.println(age);

        //获得hash结构中的所有字段
        Set keys = hashOperations.keys("002");
        for (Object key : keys) {
            System.out.println(key);
        }

        //获得hash结构中的所有值
        List values = hashOperations.values("002");
        for (Object value : values) {
            System.out.println(value);
        }
    }

    /**
     * 操作List类型的数据
     */
    @Test
    public void testList(){
        ListOperations listOperations = redisTemplate.opsForList();

        //存值
        listOperations.leftPush("mylist","a");
        listOperations.leftPushAll("mylist","b","c","d");

        //取值
        List<String> mylist = listOperations.range("mylist", 0, -1);
        for (String value : mylist) {
            System.out.println(value);
        }

        //获得列表长度 llen
        Long size = listOperations.size("mylist");
        int lSize = size.intValue();
        for (int i = 0; i < lSize; i++) {
            //出队列
            String element = (String) listOperations.rightPop("mylist");
            System.out.println(element);
        }
    }

    /**
     * 操作Set类型的数据
     */
    @Test
    public void testSet(){
        SetOperations setOperations = redisTemplate.opsForSet();

        //存值
        setOperations.add("myset","a","b","c","a");

        //取值
        Set<String> myset = setOperations.members("myset");
        for (String o : myset) {
            System.out.println(o);
        }

        //删除成员
        setOperations.remove("myset","a","b");

        //取值
        myset = setOperations.members("myset");
        for (String o : myset) {
            System.out.println(o);
        }

    }

    /**
     * 操作ZSet类型的数据
     */
    @Test
    public void testZset(){
        ZSetOperations zSetOperations = redisTemplate.opsForZSet();

        //存值
        zSetOperations.add("myZset","a",10.0);
        zSetOperations.add("myZset","b",11.0);
        zSetOperations.add("myZset","c",12.0);
        zSetOperations.add("myZset","a",13.0);

        //取值
        Set<String> myZset = zSetOperations.range("myZset", 0, -1);
        for (String s : myZset) {
            System.out.println(s);
        }

        //修改分数
        zSetOperations.incrementScore("myZset","b",20.0);

        //取值
        myZset = zSetOperations.range("myZset", 0, -1);
        for (String s : myZset) {
            System.out.println(s);
        }

        //删除成员
        zSetOperations.remove("myZset","a","b");

        //取值
        myZset = zSetOperations.range("myZset", 0, -1);
        for (String s : myZset) {
            System.out.println(s);
        }
    }

    /**
     * 通用操作，针对不同的数据类型都可以操作
     */
    @Test
    public void testCommon(){
        //获取Redis中所有的key
        Set<String> keys = redisTemplate.keys("*");
        for (String key : keys) {
            System.out.println(key);
        }

        //判断某个key是否存在
        Boolean itcast = redisTemplate.hasKey("itcast");
        System.out.println(itcast);

        //删除指定key
        redisTemplate.delete("myZset");

        //获取指定key对应的value的数据类型
        DataType dataType = redisTemplate.type("myset");
        System.out.println(dataType.name());

    }

3.Spring Cache整合redis简化缓存开发

 配置文件自行修改：

server:
  port: 8080
spring:
  application:
    #应用的名称，可选
    name: cache_demo
  datasource:
    druid:
      driver-class-name: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://localhost:3306/cache_demo?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&allowPublicKeyRetrieval=true
      username: root
      password: root
  redis:
    host: 172.17.2.94
    port: 6379
    password: root@123456
    database: 0
  cache:
    redis:
      time-to-live: 1800000 #设置缓存过期时间，可选
mybatis-plus:
  configuration:
    #在映射实体或者属性时，将数据库中表名和字段名中的下划线去掉，按照驼峰命名法映射
    map-underscore-to-camel-case: true
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
  global-config:
    db-config:
      id-type: ASSIGN_ID

 示例代码（注解的使用）：

 /**
     * CachePut：将方法返回值放入缓存
     * value：缓存的名称，每个缓存名称下面可以有多个key
     * key：缓存的key
     */
    @CachePut(value = "userCache",key = "#user.id")
    @PostMapping
    public User save(User user){
        userService.save(user);
        return user;
    }

    /**
     * CacheEvict：清理指定缓存
     * value：缓存的名称，每个缓存名称下面可以有多个key
     * key：缓存的key
     */
    @CacheEvict(value = "userCache",key = "#p0")
    //@CacheEvict(value = "userCache",key = "#root.args[0]")
    //@CacheEvict(value = "userCache",key = "#id")
    @DeleteMapping("/{id}")
    public void delete(@PathVariable Long id){
        userService.removeById(id);
    }

    //@CacheEvict(value = "userCache",key = "#p0.id")
    //@CacheEvict(value = "userCache",key = "#user.id")
    //@CacheEvict(value = "userCache",key = "#root.args[0].id")
    @CacheEvict(value = "userCache",key = "#result.id")
    @PutMapping
    public User update(User user){
        userService.updateById(user);
        return user;
    }

    /**
     * Cacheable：在方法执行前spring先查看缓存中是否有数据，如果有数据，则直接返回缓存数据；若没有数据，调用方法并将方法返回值放到缓存中
     * value：缓存的名称，每个缓存名称下面可以有多个key
     * key：缓存的key
     * condition：条件，满足条件时才缓存数据
     * unless：满足条件则不缓存（redis）
     *  
     */
    @Cacheable(value = "userCache",key = "#id",unless = "#result == null")
    @GetMapping("/{id}")
    public User getById(@PathVariable Long id){
        User user = userService.getById(id);
        return user;
    }

    @Cacheable(value = "userCache",key = "#user.id + '_' + #user.name")
    @GetMapping("/list")
    public List<User> list(User user){
        LambdaQueryWrapper<User> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(user.getId() != null,User::getId,user.getId());
        queryWrapper.eq(user.getName() != null,User::getName,user.getName());
        List<User> list = userService.list(queryWrapper);
        return list;

4.Mysql主从复制和读写分离

<1>主从复制

 

 

 

 

 

克隆的虚拟机记得先给一下mysql的uuid：

1、利用uuid函数生成新的uuid

mysql> select uuid();
+--------------------------------------+
| uuid()                               |
+--------------------------------------+
| 159d0c6b-2d39-11ed-ad53-000c29c9f5d4 |
+--------------------------------------+
1 row in set (0.00 sec)
2、查看配置文件目录

mysql> show variables like 'datadir';
+---------------+-----------------+
| Variable_name | Value           |
+---------------+-----------------+
| datadir       | /var/lib/mysql/ |
+---------------+-----------------+
1 row in set (0.03 sec)
3、编辑配置文件目录

vi /var/lib/mysql/auto.cnf
4、uuid修改新生成的uuid

server-uuid=159d0c6b-2d39-11ed-ad53-000c29c9f5d4
5、重启服务

systemctl restart mysqld
 

<2>读写分离

使用Sharding-JDBC框架实现