docs(README): 更新前后端部署说明

- 优化数据库配置步骤，增加创建数据库和导入SQL文件的详细说明
- 更新配置文件修改说明，提供更具体的配置示例
- 补充API文档访问说明
- 完善前端部署步骤，包括运行开发服务器和生产构建
- 增加SnowflakeIdUtil和TimeUtil工具类

music-houduan/src/main/java/com/test/musichouduan/util/SnowflakeIdUtil.java

@@ -0,0 +1,78 @@
+package com.test.musichouduan.util;
+
+public class SnowflakeIdUtil {
+
+    private static final long START_TIMESTAMP = 1609459200000L; // 2021-01-01 00:00:00
+
+    private static final long SEQUENCE_BIT = 12;
+    private static final long MACHINE_BIT = 5;
+    private static final long DATA_CENTER_BIT = 5;
+
+    private static final long MAX_SEQUENCE = ~(-1L << SEQUENCE_BIT);
+    private static final long MAX_MACHINE_NUM = ~(-1L << MACHINE_BIT);
+    private static final long MAX_DATA_CENTER_NUM = ~(-1L << DATA_CENTER_BIT);
+
+    private static final long MACHINE_LEFT = SEQUENCE_BIT;
+    private static final long DATA_CENTER_LEFT = SEQUENCE_BIT + MACHINE_BIT;
+    private static final long TIMESTAMP_LEFT = DATA_CENTER_LEFT + DATA_CENTER_BIT;
+
+    private long dataCenterId;
+    private long machineId;
+    private long sequence = 0L;
+    private long lastStamp = -1L;
+
+    private static SnowflakeIdUtil instance;
+
+    public static synchronized SnowflakeIdUtil getInstance() {
+        if (instance == null) {
+            instance = new SnowflakeIdUtil(1, 1);
+        }
+        return instance;
+    }
+
+    public SnowflakeIdUtil(long dataCenterId, long machineId) {
+        if (dataCenterId > MAX_DATA_CENTER_NUM || dataCenterId < 0) {
+            throw new IllegalArgumentException("Data center ID can't be greater than " + MAX_DATA_CENTER_NUM + " or less than 0");
+        }
+        if (machineId > MAX_MACHINE_NUM || machineId < 0) {
+            throw new IllegalArgumentException("Machine ID can't be greater than " + MAX_MACHINE_NUM + " or less than 0");
+        }
+        this.dataCenterId = dataCenterId;
+        this.machineId = machineId;
+    }
+
+    public synchronized long nextId() {
+        long currStamp = getNewStamp();
+        if (currStamp < lastStamp) {
+            throw new RuntimeException("Clock moved backwards. Refusing to generate id");
+        }
+
+        if (currStamp == lastStamp) {
+            sequence = (sequence + 1) & MAX_SEQUENCE;
+            if (sequence == 0L) {
+                currStamp = getNextMill();
+            }
+        } else {
+            sequence = 0L;
+        }
+
+        lastStamp = currStamp;
+
+        return (currStamp - START_TIMESTAMP) << TIMESTAMP_LEFT
+                | dataCenterId << DATA_CENTER_LEFT
+                | machineId << MACHINE_LEFT
+                | sequence;
+    }
+
+    private long getNextMill() {
+        long mill = getNewStamp();
+        while (mill <= lastStamp) {
+            mill = getNewStamp();
+        }
+        return mill;
+    }
+
+    private long getNewStamp() {
+        return System.currentTimeMillis();
+    }
+}

music-houduan/src/main/java/com/test/musichouduan/util/TimeUtil.java

@@ -0,0 +1,21 @@
+package com.test.musichouduan.util;
+
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+public class TimeUtil {
+
+    public static String getCurrentTime() {
+        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
+        return sdf.format(new Date());
+    }
+
+    public static long getTimestamp() {
+        return System.currentTimeMillis();
+    }
+
+    public static String formatDate(Date date, String format) {
+        SimpleDateFormat sdf = new SimpleDateFormat(format);
+        return sdf.format(date);
+    }
+}