36 lines
806 B
Go
36 lines
806 B
Go
package service
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import (
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"net/http"
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"strings"
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)
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// DetectFileType 根据返回的二进制内容推断 contentType + 扩展名（尽量稳定）
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func DetectFileType(data []byte) (contentType string, ext string) {
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if len(data) == 0 {
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return "application/octet-stream", ""
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}
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ct := http.DetectContentType(data)
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switch ct {
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case "audio/mpeg":
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return ct, ".mp3"
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case "audio/wave", "audio/wav", "audio/x-wav":
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return ct, ".wav"
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case "video/mp4":
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return ct, ".mp4"
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case "image/png":
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return ct, ".png"
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case "image/jpeg":
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return ct, ".jpg"
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case "application/pdf":
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return ct, ".pdf"
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default:
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// 兜底：尝试从 ct 截取 subtype 作为后缀（例如 application/json）
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if parts := strings.Split(ct, "/"); len(parts) == 2 {
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return ct, "." + parts[1]
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}
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return ct, ""
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}
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}
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