170 lines
4.2 KiB
Markdown
170 lines
4.2 KiB
Markdown
---
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title: SpringBoot Redis简介和使用
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date: 2026-03-22
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---
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# 一、简介
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  Redis是一个高性能的开源内存数据库，用作缓存、数据库和消息中间件。它以极快的读写速度（基于内存存储）支持字符串、列表、哈希等多种数据结构。Redis提供数据持久化、主从复制、哨兵模式等高可用特性，广泛应用于缓存、会话存储、排行榜、消息队列等场景。
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# 二、安装
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## 2.1 apt安装
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1. 通过apt包管理器安装：
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```bash
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sudo apt update
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sudo apt install redis-server
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sudo systemctl enable redis-server
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```
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2. 配置远程和密码访问（可选）
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  打开`/etc/redis/redis.conf`文件，更改配置：
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```conf
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bind 0.0.0.0 ::1
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protected-mode yes
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requirepass password
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```
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  `systemctl restart redis-server`重启服务。
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## 2.2 docker安装
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```yml
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services:
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redis:
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image: redis:8.6.4
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container_name: redis
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restart: always
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ports:
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- "6379:6379"
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volumes:
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- ./redis.conf:/usr/local/etc/redis/redis.conf
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- ./data:/data
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command: redis-server /usr/local/etc/redis/redis.conf
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```
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  redis.conf:
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```conf
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bind 0.0.0.0
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protected-mode yes
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port 6379
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requirepass password
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```
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## 2.3 客户端
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[Tiny RDM](https://redis.tinycraft.cc/zh/)
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# 三、SpringBoot使用
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## 3.1 引入依赖
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```xml
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<dependency>
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<groupId>org.springframework.boot</groupId>
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<artifactId>spring-boot-starter-data-redis</artifactId>
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</dependency>
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```
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## 3.2 配置文件
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```yml
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spring:
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data:
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redis:
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host: 127.0.0.1
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port: 6379
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password: 123456
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```
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::: tip
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SpringBoot2中没有data层级
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:::
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## 3.3 简单使用
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```java
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@Component
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public class RedisUtils {
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@Resource
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private StringRedisTemplate redis;
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public void set(String key, String value, long seconds) {
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redis.opsForValue().set(key, value, seconds, TimeUnit.SECONDS);
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}
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public String get(String key) {
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return redis.opsForValue().get(key);
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}
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public void delete(String key) {
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redis.delete(key);
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}
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public Boolean hasKey(String key) {
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return redis.hasKey(key);
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}
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// 匹配查询
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public Set<String> scanKeys(String pattern) {
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return redis.execute((RedisCallback<Set<String>>) connection -> {
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Set<String> keys = new HashSet<>();
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ScanOptions options = ScanOptions.scanOptions().match(pattern).count(1000).build();
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try (Cursor<byte[]> cursor = connection.keyCommands().scan(options)) {
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while (cursor.hasNext()) {
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keys.add(new String(cursor.next(), StandardCharsets.UTF_8));
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}
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} catch (Exception e) {
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throw new RuntimeException("Redis SCAN 执行失败，pattern=" + pattern, e);
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}
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return keys;
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});
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}
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}
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```
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::: tip
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生产环境中使用`scan`命令批量查询`key`值，`keys`命令会阻塞`Redis`线程。
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:::
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# 四、实战
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## 4.1 设备在线功能
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  实现一个统计设备是否实时在线的功能。
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```java
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@RestController
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@RequestMapping("/device")
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public class DeviceController {
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@Resource
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private RedisUtils redisUtils;
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private static final String HEARTBEAT_KEY = "device:heartbeat:";
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private static final long EXPIRE_SECONDS = 40;
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/**
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* 设备心跳接口
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* 设备每20-30秒调用一次
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* 心跳key 40秒后过期，过期即认为设备离线
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*/
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@PostMapping("/heartbeat")
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public Boolean heartbeat(@RequestParam String deviceId) {
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redisUtils.set(HEARTBEAT_KEY + deviceId, String.valueOf(System.currentTimeMillis()), EXPIRE_SECONDS);
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return Boolean.TRUE;
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}
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/**
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* 获取当前在线设备列表
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*/
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@GetMapping("/online")
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public Set<String> getOnlineDevices() {
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Set<String> keys = redisUtils.scanKeys(HEARTBEAT_KEY + "*");
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Set<String> deviceIds = new HashSet<>();
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for (String key : keys) {
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String deviceId = key.substring(HEARTBEAT_KEY.length());
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deviceIds.add(deviceId);
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}
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return deviceIds;
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}
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}
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```
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  客户端每30秒调用一次`/device/heartbeat`接口。 |