Đọc và Ghi File trong Swift

import Foundation
 
// Documents directory
let documentsPath = FileManager.default.urls(
    for: .documentDirectory,
    in: .userDomainMask
)[0]
 
// Tạo file path
let filePath = documentsPath.appendingPathComponent("data.txt")
print(filePath.path)

let text = "Hello, Swift!"
let filePath = documentsPath.appendingPathComponent("greeting.txt")
 
do {
    try text.write(to: filePath, atomically: true, encoding: .utf8)
    print("File written successfully")
} catch {
    print("Error writing file: \(error)")
}

let filePath = documentsPath.appendingPathComponent("greeting.txt")
 
do {
    let content = try String(contentsOf: filePath, encoding: .utf8)
    print(content)
} catch {
    print("Error reading file: \(error)")
}

let data = "Binary content".data(using: .utf8)!
let filePath = documentsPath.appendingPathComponent("data.bin")
 
do {
    try data.write(to: filePath)
} catch {
    print("Error: \(error)")
}

do {
    let data = try Data(contentsOf: filePath)
    if let content = String(data: data, encoding: .utf8) {
        print(content)
    }
} catch {
    print("Error: \(error)")
}

let fileManager = FileManager.default
 
// Kiểm tra tồn tại
if fileManager.fileExists(atPath: filePath.path) {
    print("File exists")
}
 
// Xóa file
try? fileManager.removeItem(at: filePath)
 
// Copy file
try? fileManager.copyItem(at: source, to: destination)
 
// Move file
try? fileManager.moveItem(at: source, to: destination)

let fileManager = FileManager.default
let newDir = documentsPath.appendingPathComponent("MyFolder")
 
// Tạo directory
try? fileManager.createDirectory(
    at: newDir,
    withIntermediateDirectories: true,
    attributes: nil
)
 
// Liệt kê files
if let contents = try? fileManager.contentsOfDirectory(atPath: newDir.path) {
    for item in contents {
        print(item)
    }
}

let filePath = documentsPath.appendingPathComponent("data.txt")
 
if let attributes = try? fileManager.attributesOfItem(atPath: filePath.path) {
    let size = attributes[.size] as? Int64 ?? 0
    let modDate = attributes[.modificationDate] as? Date
    
    print("Size: \(size) bytes")
    print("Modified: \(modDate?.description ?? "Unknown")")
}

struct User: Codable {
    let name: String
    let age: Int
}
 
// Ghi JSON
let user = User(name: "Alice", age: 25)
let filePath = documentsPath.appendingPathComponent("user.json")
 
do {
    let encoder = JSONEncoder()
    encoder.outputFormatting = .prettyPrinted
    let data = try encoder.encode(user)
    try data.write(to: filePath)
} catch {
    print("Error: \(error)")
}
 
// Đọc JSON
do {
    let data = try Data(contentsOf: filePath)
    let user = try JSONDecoder().decode(User.self, from: data)
    print(user)
} catch {
    print("Error: \(error)")
}