feat:增加Redis文档

docs/.vitepress/theme/router/index.ts

@@ -37,7 +37,8 @@ export const routers = [
           { text: 'SpringBoot3原生镜像', link: '/Web-Backend/SpringBoot/SpringBoot3-GraalVM' },
           { text: 'SpringBoot技巧', link: '/Web-Backend/SpringBoot/SpringBoot-Skills' },
           { text: 'SpringBoot Common', link: '/Web-Backend/SpringBoot/SpringBoot-Common' },
-          { text: 'SpringBoot RestClient简介', link: '/Web-Backend/SpringBoot/SpringBoot-RestClient' }
+          { text: 'SpringBoot RestClient简介', link: '/Web-Backend/SpringBoot/SpringBoot-RestClient' },
+          { text: 'SpringBoot Redis简介和使用', link: '/Web-Backend/SpringBoot/SpringBoot-Redis' }
         ]
       },
       {

docs/Web-Backend/SpringBoot/SpringBoot-Redis.md

@@ -0,0 +1,142 @@
+---
+  title: SpringBoot Redis简介和使用
+  date: 2026-03-22
+---
+
+# 一、简介
+  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。  
+
+# 二、安装
+1. 通过apt包管理器安装：   
+```bash
+sudo apt update
+sudo apt install redis-server
+sudo systemctl enable redis-server
+```
+
+2. 配置远程和密码访问（可选）
+
+  打开`/etc/redis/redis.conf`文件，更改配置：
+```conf
+bind 0.0.0.0 ::1
+protected-mode yes 
+requirepass password
+```
+
+  `systemctl restart redis-server`重启服务。  
+
+# 三、SpringBoot使用
+## 3.1 引入依赖
+```xml
+<dependency>
+    <groupId>org.springframework.boot</groupId>
+    <artifactId>spring-boot-starter-data-redis</artifactId>
+</dependency>
+```
+
+## 3.2 配置文件
+```yml
+spring:
+  data:
+    redis:
+      host: 127.0.0.1
+      port: 6379
+      password: 123456
+```
+
+::: tip
+SpringBoot2中没有data层级
+:::
+
+## 3.3 简单使用
+```java
+@Component
+public class RedisUtils {
+
+    @Resource
+    private StringRedisTemplate redis;
+
+    public void set(String key, String value, long seconds) {
+        redis.opsForValue().set(key, value, seconds, TimeUnit.SECONDS);
+    }
+
+    public String get(String key) {
+        return redis.opsForValue().get(key);
+    }
+
+    public void delete(String key) {
+        redis.delete(key);
+    }
+
+    public Boolean hasKey(String key) {
+        return redis.hasKey(key);
+    }
+
+    // 匹配查询
+    public Set<String> scanKeys(String pattern) {
+        return redis.execute((RedisCallback<Set<String>>) connection -> {
+            Set<String> keys = new HashSet<>();
+            ScanOptions options = ScanOptions.scanOptions().match(pattern).count(1000).build();
+
+            try (Cursor<byte[]> cursor = connection.keyCommands().scan(options)) {
+                while (cursor.hasNext()) {
+                    keys.add(new String(cursor.next(), StandardCharsets.UTF_8));
+                }
+            } catch (Exception e) {
+                throw new RuntimeException("Redis SCAN 执行失败，pattern=" + pattern, e);
+            }
+
+            return keys;
+        });
+    }
+}
+```
+
+::: tip
+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。  
+:::
+
+# 四、实战
+## 4.1 设备在线功能
+&emsp;&emsp;实现一个统计设备是否实时在线的功能。   
+```java
+@RestController
+@RequestMapping("/device")
+public class DeviceController {
+
+    @Resource
+    private RedisUtils redisUtils;
+
+    private static final String HEARTBEAT_KEY = "device:heartbeat:";
+    private static final long EXPIRE_SECONDS = 40;
+
+    /**
+     * 设备心跳接口
+     * 设备每20-30秒调用一次
+     * 心跳key 40秒后过期，过期即认为设备离线
+     */
+    @PostMapping("/heartbeat")
+    public Boolean heartbeat(@RequestParam String deviceId) {
+        redisUtils.set(HEARTBEAT_KEY + deviceId, String.valueOf(System.currentTimeMillis()), EXPIRE_SECONDS);
+        return Boolean.TRUE;
+    }
+
+    /**
+     * 获取当前在线设备列表
+     */
+    @GetMapping("/online")
+    public Set<String> getOnlineDevices() {
+        Set<String> keys = redisUtils.scanKeys(HEARTBEAT_KEY + "*");
+        Set<String> deviceIds = new HashSet<>();
+
+        for (String key : keys) {
+            String deviceId = key.substring(HEARTBEAT_KEY.length());
+            deviceIds.add(deviceId);
+        }
+
+        return deviceIds;
+    }
+}
+```
+
+&emsp;&emsp;客户端每30秒调用一次`/device/heartbeat`接口。