PHP通用文件处理与格式转换引擎

PHP通用文件处理与格式转换引擎

文件格式转换是常见需求。PHP可以处理多种文件格式的转换。今天说说PHP中通用文件处理引擎的实现。

文件格式检测和读取是处理的第一步。

```php
interface FileReader
{
public function read(string $path): array;
public function supports(string $extension): bool;
}

interface FileWriter
{
public function write(string $path, array $data): void;
public function supports(string $extension): bool;
}

class CsvReader implements FileReader
{
public function read(string $path): array
{
$handle = fopen($path, 'r');
$headers = fgetcsv($handle);
$data = [];

while (($row = fgetcsv($handle)) !== false) {
$row = array_map(function ($value) {
$value = trim($value);
if (is_numeric($value)) return str_contains($value, '.') ? (float)$value : (int)$value;
return $value;
}, $row);
$data[] = $headers ? array_combine($headers, $row) : $row;
}

fclose($handle);
return $data;
}

public function supports(string $extension): bool
{
return in_array(strtolower($extension), ['csv', 'tsv']);
}
}

class JsonReader implements FileReader
{
public function read(string $path): array
{
$content = file_get_contents($path);
$data = json_decode($content, true);
if ($data === null) {
throw new \RuntimeException("JSON解析失败: " . json_last_error_msg());
}
return $data;
}

public function supports(string $extension): bool
{
return strtolower($extension) === 'json';
}
}

class XmlReader implements FileReader
{
public function read(string $path): array
{
$xml = simplexml_load_file($path);
$json = json_encode($xml);
return json_decode($json, true);
}

public function supports(string $extension): bool
{
return in_array(strtolower($extension), ['xml', 'xmls']);
}
}

class CsvWriter implements FileWriter
{
public function write(string $path, array $data): void
{
$handle = fopen($path, 'w');
if (!empty($data)) {
fputcsv($handle, array_keys($data[0]));
foreach ($data as $row) {
fputcsv($handle, $row);
}
}
fclose($handle);
}

public function supports(string $extension): bool
{
return strtolower($extension) === 'csv';
}
}

class JsonWriter implements FileWriter
{
public function write(string $path, array $data): void
{
file_put_contents($path, json_encode($data, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE));
}

public function supports(string $extension): bool
{
return strtolower($extension) === 'json';
}
}

class FileConversionEngine
{
private array $readers = [];
private array $writers = [];

public function __construct()
{
$this->registerDefaultReaders();
$this->registerDefaultWriters();
}

public function registerReader(FileReader $reader): void
{
$this->readers[] = $reader;
}

public function registerWriter(FileWriter $writer): void
{
$this->writers[] = $writer;
}

public function convert(string $sourcePath, string $destPath): void
{
$sourceExt = pathinfo($sourcePath, PATHINFO_EXTENSION);
$destExt = pathinfo($destPath, PATHINFO_EXTENSION);

$reader = $this->findReader($sourceExt);
if ($reader === null) {
throw new \RuntimeException("不支持的源格式: {$sourceExt}");
}

$writer = $this->findWriter($destExt);
if ($writer === null) {
throw new \RuntimeException("不支持的目标格式: {$destExt}");
}

echo "正在读取: {$sourcePath}\n";
$data = $reader->read($sourcePath);

echo "正在写入: {$destPath}\n";
$writer->write($destPath, $data);

echo "转换完成\n";
}

public function getSupportedFormats(): array
{
$readFormats = [];
foreach ($this->readers as $reader) {
$readFormats[] = $reader;
}
return [
'readable' => $readFormats,
'writable' => $this->writers,
];
}

private function registerDefaultReaders(): void
{
$this->readers[] = new CsvReader();
$this->readers[] = new JsonReader();
$this->readers[] = new XmlReader();
}

private function registerDefaultWriters(): void
{
$this->writers[] = new CsvWriter();
$this->writers[] = new JsonWriter();
}

private function findReader(string $extension): ?FileReader
{
foreach ($this->readers as $reader) {
if ($reader->supports($extension)) return $reader;
}
return null;
}

private function findWriter(string $extension): ?FileWriter
{
foreach ($this->writers as $writer) {
if ($writer->supports($extension)) return $writer;
}
return null;
}
}

$engine = new FileConversionEngine();

$tempDir = '/tmp/conversion_test';
if (!is_dir($tempDir)) mkdir($tempDir, 0755, true);

$csvFile = "{$tempDir}/test.csv";
$fp = fopen($csvFile, 'w');
fputcsv($fp, ['name', 'age', 'email']);
fputcsv($fp, ['张三', 28, '[e-mail]']);
fputcsv($fp, ['李四', 35, '[e-mail]']);
fclose($fp);

try {
$engine->convert($csvFile, "{$tempDir}/output.json");
$engine->convert($csvFile, "{$tempDir}/output.xml");

$jsonData = json_decode(file_get_contents("{$tempDir}/output.json"), true);
print_r($jsonData);
} catch (\Exception $e) {
echo "错误: {$e->getMessage()}\n";
}
?>

文件转换引擎通过策略模式实现了格式的可扩展性。添加新的文件格式只需要注册对应的Reader和Writer类。这种设计让引擎可以处理多种文件格式的相互转换，包括CSV、JSON、XML等常见格式。