java - 如何在 Spring4 Rest api 中流式传输大型 csv？

Question

我正在使用 spring 4 web-mvc 创建一个rest api。我有一个巨大的 csv 文件想要流式传输。在 python 中我可以做的非常简单:

from flask import Response

@app.route('/large.csv')
def generate_large_csv():
    def generate():
        for row in iter_all_rows():
            yield ','.join(row) + '\n'
    return Response(generate(), mimetype='text/csv')

Spring 4 中的等效项是什么？这可能吗？

Answer 1

下面是伪代码作为提示:

@RequestMapping(value = "/large.csv", method = GET, produces = "text/csv")
@ResponseStatus(value = HttpStatus.OK)
public void streamLargeCSV(OutputStream output) {
    InputStream is = new FileInputStream(csvFile);
    int read=0;
    byte[] bytes = new byte[1024 * 4];  //size per read

    while((read = is.read(bytes))!= -1){
        output.write(bytes, 0, read);
        output.flush();  //may change flush rate to more rows/flush
    }
    output.close()
}