spring boot中如何将csv文件使用流的方式返回给浏览器呢？

实现思路:
    1.引入Apache的commons-csv的jar包
	2.使用CSVPrinter对象中的方法
	 即可将csv转换为流返回

1.导入pom依赖
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-csv</artifactId>
    <version>1.5</version>
</dependency>
 
2 controller测试
@GetMapping("/csv")
    public ResponseEntity<byte[]> csv() throws Exception {
        CSVFormat csvFormat = CSVFormat.DEFAULT.withHeader("1", "2", "3");
        File tempFile = File.createTempFile("vehicle", ".csv");
        FileOutputStream fileOutputStream = new FileOutputStream(tempFile);
        CSVPrinter csvPrinter = new CSVPrinter(new OutputStreamWriter(fileOutputStream), csvFormat);
        for (int i = 0; i <88; i++) {
            csvPrinter.printRecord("q", "w", "e");
        }
        csvPrinter.flush();
        csvPrinter.close();
        fileOutputStream.close();
        FileInputStream fis = new FileInputStream(tempFile);
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        byte[] b = new byte[1024];
        int n;
        while ((n = fis.read(b)) != -1)
        {
            bos.write(b, 0, n);
        }
        fis.close();
        bos.close();
        HttpHeaders httpHeaders = new HttpHeaders();
        String fileName = new String("测试.csv".getBytes("UTF-8"), "iso-8859-1");
        httpHeaders.setContentDispositionFormData("attachment", fileName);
        httpHeaders.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        ResponseEntity<byte[]> filebyte = new ResponseEntity<byte[]>(bos.toByteArray(), httpHeaders, HttpStatus.CREATED);
        return filebyte;
    }