合并文件夹用的NSFileManager，只覆盖现有文件

Question

基本上我在找一种与可可API文件系统合并两个文件夹：

我有一个包含文件和子文件夹，这是我想要的文件夹复制到文件系统中的其他位置。
在我的目标路径中，同名文件夹已经存在，它也可能包含文件和文件夹。

现在我想用我的源文件夹的新内容覆盖目标文件夹（或其子文件夹）内的现有文件，如果它们具有相同的名称。
我想保留所有其他文件不变。

sourcefolder 
    | 
    - file1 
    - subfolder 
     - file2 


destinationfolder 
    | 
    - file3 
    - subfolder 
     - file2 
     - file4 


resultingfolder 
    | 
    - file1 
    - file3 
    - subfolder 
     - file2  <-- version from source folder 
     - file4 

我该怎么做？ 非常感谢您的帮助！

Answer 1

我到处搜索，但什么也没找到。所以我想出了我自己的解决方案，利用NSDirectoryEnumerator。这应该工作图（重写旧文件）。希望能帮助到你。

- (void)mergeContentsOfPath:(NSString *)srcDir intoPath:(NSString *)dstDir error:(NSError**)err { 

    NSLog(@"- mergeContentsOfPath: %@\n intoPath: %@", srcDir, dstDir); 

    NSFileManager *fm = [NSFileManager defaultManager]; 
    NSDirectoryEnumerator *srcDirEnum = [fm enumeratorAtPath:srcDir]; 
    NSString *subPath; 
    while ((subPath = [srcDirEnum nextObject])) { 

     NSLog(@" subPath: %@", subPath); 
     NSString *srcFullPath = [srcDir stringByAppendingPathComponent:subPath]; 
     NSString *potentialDstPath = [dstDir stringByAppendingPathComponent:subPath]; 

     // Need to also check if file exists because if it doesn't, value of `isDirectory` is undefined. 
     BOOL isDirectory = ([[NSFileManager defaultManager] fileExistsAtPath:srcFullPath isDirectory:&isDirectory] && isDirectory); 

     // Create directory, or delete existing file and move file to destination 
     if (isDirectory) { 
      NSLog(@" create directory"); 
      [fm createDirectoryAtPath:potentialDstPath withIntermediateDirectories:YES attributes:nil error:err]; 
      if (err && *err) { 
       NSLog(@"ERROR: %@", *err); 
       return; 
      } 
     } 
     else { 
      if ([fm fileExistsAtPath:potentialDstPath]) { 
       NSLog(@" removeItemAtPath"); 
       [fm removeItemAtPath:potentialDstPath error:err]; 
       if (err && *err) { 
        NSLog(@"ERROR: %@", *err); 
        return; 
       } 
      } 

      NSLog(@" moveItemAtPath"); 
      [fm moveItemAtPath:srcFullPath toPath:potentialDstPath error:err]; 
      if (err && *err) { 
       NSLog(@"ERROR: %@", *err); 
       return; 
      } 
     } 
    } 
} 

Answer 2

看文件管理方法和，而不是使用默认的文件管理器，创建你自己与分配/初始化，设置一个委托，并使用委托方法。

Answer 3

在夫特3

let merger = FoldersMerger(actionType: .copy, conflictResolution: .keepSource) 
merger.merge(atPath: sourceFolder, toPath: destinationFolder) 


class FoldersMerger { 

    enum ActionType { case move, copy } 
    enum ConflictResolution { case keepSource, keepDestination } 

    private let fileManager = FileManager() 
    private var actionType: ActionType! 
    private var conflictResolution: ConflictResolution! 
    private var deleteEmptyFolders: Bool! 

    init(actionType: ActionType = .move, conflictResolution: ConflictResolution = .keepDestination, deleteEmptyFolders: Bool = false) { 
     self.actionType = actionType 
     self.conflictResolution = conflictResolution 
     self.deleteEmptyFolders = deleteEmptyFolders 
    } 

    func merge(atPath: String, toPath: String) { 
     let pathEnumerator = fileManager.enumerator(atPath: atPath) 

     var folders: [String] = [atPath] 

     while let relativePath = pathEnumerator?.nextObject() as? String { 

      let subItemAtPath = URL(fileURLWithPath: atPath).appendingPathComponent(relativePath).path 
      let subItemToPath = URL(fileURLWithPath: toPath).appendingPathComponent(relativePath).path 

      if isDir(atPath: subItemAtPath) { 

       if deleteEmptyFolders! { 
        folders.append(subItemAtPath) 
       } 

       if !isDir(atPath: subItemToPath) { 
        do { 
         try fileManager.createDirectory(atPath: subItemToPath, withIntermediateDirectories: true, attributes: nil) 
         NSLog("FoldersMerger: directory created: %@", subItemToPath) 
        } 
        catch let error { 
         NSLog("ERROR FoldersMerger: %@", error.localizedDescription) 
        } 
       } 
       else { 
        NSLog("FoldersMerger: directory %@ already exists", subItemToPath) 
       } 
      } 
      else { 

       if isFile(atPath:subItemToPath) && conflictResolution == .keepSource { 
        do { 
         try fileManager.removeItem(atPath: subItemToPath) 
         NSLog("FoldersMerger: file deleted: %@", subItemToPath) 
        } 
        catch let error { 
         NSLog("ERROR FoldersMerger: %@", error.localizedDescription) 
        } 
       } 

       do { 
        try fileManager.moveItem(atPath: subItemAtPath, toPath: subItemToPath) 
        NSLog("FoldersMerger: file moved from %@ to %@", subItemAtPath, subItemToPath) 
       } 
       catch let error { 
        NSLog("ERROR FoldersMerger: %@", error.localizedDescription) 
       } 
      } 
     } 

     if deleteEmptyFolders! { 
      folders.sort(by: { (path1, path2) -> Bool in 
       return path1.characters.split(separator: "/").count < path2.characters.split(separator: "/").count 
      }) 
      while let folderPath = folders.popLast() { 
       if isDirEmpty(atPath: folderPath) { 
        do { 
         try fileManager.removeItem(atPath: folderPath) 
         NSLog("FoldersMerger: empty dir deleted: %@", folderPath) 
        } 
        catch { 
         NSLog("ERROR FoldersMerger: %@", error.localizedDescription) 
        } 
       } 
      } 
     } 
    } 

    private func isDir(atPath: String) -> Bool { 
     var isDir: ObjCBool = false 
     let exist = fileManager.fileExists(atPath: atPath, isDirectory: &isDir) 
     return exist && isDir.boolValue 
    } 

    private func isFile(atPath: String) -> Bool { 
     var isDir: ObjCBool = false 
     let exist = fileManager.fileExists(atPath: atPath, isDirectory: &isDir) 
     return exist && !isDir.boolValue 
    } 

    private func isDirEmpty(atPath: String) -> Bool { 
     do { 
      return try fileManager.contentsOfDirectory(atPath: atPath).count == 0 
     } 
     catch _ { 
      return false 
     } 
    } 
}