初始化

lib/hj_utils/file_util.dart

@@ -0,0 +1,99 @@
+// ignore_for_file: constant_identifier_names
+
+import 'dart:io';
+import 'dart:typed_data';
+
+import 'package:hgdj/extension/extensions.dart';
+import 'package:hgdj/hj_utils/text_util.dart';
+import 'package:hgdj/tools_base/debug_log.dart';
+
+const KB_SIZE = 1024;
+const MB_SIZE = 1024 * KB_SIZE;
+const GB_SIZE = 1024 * MB_SIZE;
+
+/// 文件相关的公共处理
+class FileUtil {
+  /// 计算切片个数
+  static int getPatchCount(int fileLen) {
+    final cutSize = getPatchSize(fileLen);
+    return (fileLen + cutSize - 1) ~/ cutSize;
+  }
+
+  /// 根据文件长度计算切片大小
+  static int getPatchSize(int fileLen) {
+    if (fileLen < MB_SIZE) return MB_SIZE;
+    return 2 * MB_SIZE;
+  }
+
+  /// 文件是否存在
+  static bool isFileExist(String path) {
+    return TextUtil.isNotEmpty(path) && File(path).existsSync();
+  }
+
+  /// 获取 file 从 offset 之后到 blockSize 的数据块
+  /// [offset]    起始偏移位置
+  /// [blockSize] 分块大小
+  /// [file]      文件
+  static Future<Uint8List> getFileBlock(
+      int offset, int blockSize, File file) async {
+    RandomAccessFile? accessFile;
+    try {
+      accessFile = await file.open();
+      await accessFile.setPosition(offset);
+      debugLog('offset:$offset blocksize:$blockSize');
+      return await accessFile.read(blockSize);
+    } on Exception {
+      return Uint8List(0);
+    } finally {
+      accessFile?.close();
+    }
+  }
+
+  /// 获取文件长度
+  static int getFileSize(String path) {
+    if (!isFileExist(path)) return 0;
+    return File(path).lengthSync();
+  }
+
+  /// 获取文件的格式化大小
+  static String byteFmt(int size) {
+    if (size > GB_SIZE) {
+      return '${(size / GB_SIZE).toStringAsFixed(1)}GB';
+    } else if (size > MB_SIZE) {
+      return '${(size / MB_SIZE).toStringAsFixed(1)}MB';
+    } else {
+      return '${(size / KB_SIZE).toStringAsFixed(1)}KB';
+    }
+  }
+
+  /// 获取文件名带后缀
+  /// 支持 url/uri/file/abspath
+  static String getName(String absPath) {
+    if (TextUtil.isEmpty(absPath)) return absPath;
+    absPath = Uri.parse(absPath).path;
+    final start = absPath.lastIndexOf('/');
+    if (start <= 0 || start == absPath.length - 1) {
+      return absPath;
+    }
+    return absPath.substring(start + 1);
+  }
+
+  /// 获取文件名不带后缀
+  static String getNamePrefix(String absPath) {
+    final name = getName(absPath);
+    if (TextUtil.isEmpty(name)) return name;
+    final ar = name.split('.');
+    if (ar.empty()) return name;
+    return ar[0];
+  }
+
+  /// 获取文件名后缀 (fileExtension)
+  static String getNameSuffix(String absPath) {
+    final name = getName(absPath);
+    if (TextUtil.isEmpty(name)) return name;
+    final ar = name.split('.');
+    if (ar.empty()) return name;
+    if (ar.length < 2) return ar[0];
+    return ar.last;
+  }
+}