servlet/rest控制器下载log4j日志文件内容未完全结束

在一个SpringWeb应用程序中(虽然我不认为这与Spring有关),我创建了一个REST GET资源,允许下载当前的log4j2文件内容,但是请求(来自浏览器和cUrl)不会随着部署在远程生产服务器上的webapp而终止,而它们通常会在我的Windows开发机器上结束。

而且,cUrl说还有字节要接收:

* transfer closed with 3 bytes remaining to read
* stopped the pause stream!
* Closing connection 0
curl: (18) transfer closed with 3 bytes remaining to read

这是相关代码:

// ...
import org.springframework.http.HttpHeaders;
// ...
@RestController
@RequestMapping(path="/logs", produces="application/json")
public class LogController {

    // ... 

    @GetMapping(path="/{appenderName}/contents", produces="text/plain")
    public void download(@PathVariable String appenderName, HttpServletResponse response) {

        // ...

        org.apache.logging.log4j.Logger rootLogger = LogManager.getRootLogger();
        if(rootLogger instanceof Logger) {
            Logger l = (Logger) rootLogger;

            if(l.getAppenders().containsKey(appenderName)) {
                Appender appender = l.getAppenders().get(appenderName);

                if(appender instanceof FileAppender) {
                    ((FileAppender) appender).getManager().flush();
                    final File f = new File(((FileAppender) appender).getFileName());

                    response.setHeader(HttpHeaders.CONTENT_TYPE, "text/plain");
                    response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + f.getName() + "\"");

                    Path tempCopy = Files.createTempFile("log-", null);
                    Files.copy(f.toPath(), tempCopy, StandardCopyOption.REPLACE_EXISTING);

                    response.setHeader(HttpHeaders.CONTENT_LENGTH, String.valueOf(tempCopy.toFile().length()));

                    Reader reader = new FileReader(tempCopy.toFile());
                    IOUtils.copy(reader, response.getWriter());

                    reader.close();
                    tempCopy.toFile().delete();

                    // ...

Content-length header:在Linux(Ubuntu)服务器上,只有减去 3 文件长度:

response.setHeader(HttpHeaders.CONTENT_LENGTH, String.valueOf(tempCopy.toFile().length() - 3));

当然,如果我不寄,一切都好 Content-Length 标题。