# 串流資料 { #stream-data }

如果你要串流可用 JSON 結構化的資料，應該[串流 JSON Lines](../tutorial/stream-json-lines.md)。

但如果你想串流純二進位資料或字串，以下是做法。

/// info

已在 FastAPI 0.134.0 新增。

///

## 使用情境 { #use-cases }

當你想串流純字串時可以用這個機制，例如直接轉發來自 AI LLM 服務的輸出。

你也可以用它來串流大型二進位檔案，邊讀邊將每個區塊（chunk）串流出去，而不必一次把整個檔案載入記憶體。

你也可以用同樣方式串流視訊或音訊，甚至可以在處理的同時即時產生並傳送。

## 使用 `yield` 的 `StreamingResponse` { #a-streamingresponse-with-yield }

# 서버 전송 이벤트(SSE) { #server-sent-events-sse }

브라우저 클라이언트로 데이터를 스트리밍하려면 **Server-Sent Events**(SSE)를 사용할 수 있습니다.

이는 [JSON Lines 스트리밍](stream-json-lines.md)과 비슷하지만, 브라우저가 기본적으로 [`EventSource` API](https://developer.mozilla.org/en-US/docs/Web/API/EventSource)를 통해 지원하는 `text/event-stream` 형식을 사용합니다.

/// info | 정보

FastAPI 0.135.0에 추가되었습니다.

///

## Server-Sent Events란 { #what-are-server-sent-events }

            long id = 0;
            String line = null;
            while ((line = reader.readLine()) != null) {
                // Remove comments
                final String replacedLine = line.replaceAll("#.*$", StringUtil.EMPTY).trim();

                // Skip empty lines or comment lines
                if (replacedLine.length() == 0) {
                    if (updater != null) {

It is just a function that can take all the same parameters that a *path operation function* can take:

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[8:9] *}

That's it.

**2 lines**.

And it has the same shape and structure that all your *path operation functions* have.

You can think of it as a *path operation function* without the "decorator" (without the `@app.get("/some-path")`).

Please follow these formatting guidelines:

* Java indent is 4 spaces
* Line width is 140 characters
* Lines of code surrounded by `// tag::NAME` and `// end::NAME` comments are included
  in the documentation and should only be 76 characters wide not counting
  leading indentation. Such regions of code are not formatted automatically as
  it is not possible to change the line length rule of the formatter for

}

func buildServerCtxt(ctx *cli.Context, ctxt *serverCtxt) (err error) {
	// Get "json" flag from command line argument and
	ctxt.JSON = ctx.IsSet("json") || ctx.GlobalIsSet("json")
	// Get quiet flag from command line argument.
	ctxt.Quiet = ctx.IsSet("quiet") || ctx.GlobalIsSet("quiet")
	// Get anonymous flag from command line argument.
	ctxt.Anonymous = ctx.IsSet("anonymous") || ctx.GlobalIsSet("anonymous")
	// Fetch address option

                        // The regex `^\\s*\\[\\[(.*)\\]\\]` looks for lines starting with '[[...]]'
                        // and captures the content within the brackets.
                        Files.readAllLines(file).forEach(line -> {
                            if (line.matches("^\\s*\\[\\[(.*)\\]\\].*")) {
                                String anchorName = line.replaceAll("^\\s*\\[\\[(.*)\\]\\].*$", "$1");

            String line;
            while ((line = reader.readLine()) != null) {
                line = line.replaceFirst("\\s*\\* ?", "");
                if (line.startsWith("@")) {
                    // Ignore the tag section of the comment
                    break;
                }
                builder.append(line);
                builder.append("\n");
            }

    * So, by using FastAPI you are saving development time, bugs, lines of code, and you would probably get the same performance (or better) you would if you didn't use it (as you would have to implement it all in your code).

        }
    }

    @Test
    public void test_reload_withEmptyLines() throws Exception {
        // Create content with empty lines and comments
        String content = "# Comment line\n" + "\n" + // empty line
                "word1\n" + "  \n" + // whitespace line (may be treated as content)
                "# Another comment\n" + "word2\n";

        // Write content to test file
        writeTestFile(content);