diff --git a/utils/redis-util.js b/utils/redis-util.js
index 023e34c..cd1ddf4 100644
--- a/utils/redis-util.js
+++ b/utils/redis-util.js
@@ -2,6 +2,9 @@
  * 判断某个key是否存在
  * @param key
  * @returns {Promise<boolean>}
+ * @example
+ * const exists = await redisExistKey('myKey');
+ * console.log(exists); // true or false
  */
 export async function redisExistKey(key) {
     return redis.exists(key);
@@ -11,6 +14,9 @@ export async function redisExistKey(key) {
  * 获取某个key的值
  * @param key
  * @returns {Promise<Object>}
+ * @example
+ * const value = await redisGetKey('myKey');
+ * console.log(value); // { ... }
  */
 export async function redisGetKey(key) {
     return JSON.parse(await redis.get(key));
@@ -21,6 +27,8 @@ export async function redisGetKey(key) {
  * @param key
  * @param value
  * @returns {Promise<*>}
+ * @example
+ * await redisSetKey('myKey', { foo: 'bar' });
  */
 export async function redisSetKey(key, value = {}) {
     return redis.set(
@@ -33,6 +41,9 @@ export async function redisSetKey(key, value = {}) {
  * 判断是否存在这个key然后再取值，如果没有就返回null
  * @param key
  * @returns {Promise<Object|Array>}
+ * @example
+ * const value = await redisExistAndGetKey('myKey');
+ * console.log(value); // { ... } or null
  */
 export async function redisExistAndGetKey(key) {
     if (await redisExistKey(key)) {
@@ -46,11 +57,13 @@ export async function redisExistAndGetKey(key) {
  * @param key
  * @param obj
  * @returns {Promise<void>}
+ * @example
+ * await redisExistAndInsertObject('myKey', { newKey: 'newValue' });
  */
 export async function redisExistAndInsertObject(key, obj) {
     let objs = await redisExistAndGetKey(key);
     if (objs) {
-        objs = {...objs, ...obj};
+        objs = { ...objs, ...obj };
         await redisSetKey(key, objs);
     } else {
         await redisSetKey(key, obj);
@@ -63,6 +76,8 @@ export async function redisExistAndInsertObject(key, obj) {
  * @param updateKey
  * @param updateObj
  * @returns {Promise<void>}
+ * @example
+ * await redisExistAndUpdateObject('myKey', 'updateKey', { foo: 'bar' });
  */
 export async function redisExistAndUpdateObject(key, updateKey, updateObj) {
     let objs = await redisExistAndGetKey(key);
@@ -70,4 +85,52 @@ export async function redisExistAndUpdateObject(key, updateKey, updateObj) {
         objs[updateKey] = updateObj;
         await redisSetKey(key, objs);
     }
+}
+
+/**
+ * 删除某个key
+ * @param key
+ * @returns {Promise<number>}
+ * @example
+ * const result = await redisDeleteKey('myKey');
+ * console.log(result); // 1 if key was deleted, 0 if key did not exist
+ */
+export async function redisDeleteKey(key) {
+    return redis.del(key);
+}
+
+/**
+ * 获取所有的key
+ * @returns {Promise<Array<string>>}
+ * @example
+ * const keys = await redisGetAllKeys();
+ * console.log(keys); // ['key1', 'key2', ...]
+ */
+export async function redisGetAllKeys() {
+    return redis.keys('*');
+}
+
+/**
+ * 设置某个key的过期时间
+ * @param key
+ * @param seconds
+ * @returns {Promise<boolean>}
+ * @example
+ * const result = await redisExpireKey('myKey', 3600);
+ * console.log(result); // true if timeout was set, false if key does not exist
+ */
+export async function redisExpireKey(key, seconds) {
+    return redis.expire(key, seconds);
+}
+
+/**
+ * 获取某个key的剩余生存时间
+ * @param key
+ * @returns {Promise<number>}
+ * @example
+ * const ttl = await redisTTLKey('myKey');
+ * console.log(ttl); // time to live in seconds, -1 if key does not have timeout, -2 if key does not exist
+ */
+export async function redisTTLKey(key) {
+    return redis.ttl(key);
 }
\ No newline at end of file