在Spring 3.0中，您可以使用HttpEntity返回对象。如果您使用它，那么您的控制器就不需要HttpServletResponse对象，因此它更容易测试。 除了这个，这个答案是相对等于Infeligo的答案。

如果你的pdf框架的返回值是一个字节数组(阅读我回答的其他返回值的第二部分):

@RequestMapping(value = "/files/{fileName}", method = RequestMethod.GET)
public HttpEntity<byte[]> createPdf(
                 @PathVariable("fileName") String fileName) throws IOException {

    byte[] documentBody = this.pdfFramework.createPdf(filename);

    HttpHeaders header = new HttpHeaders();
    header.setContentType(MediaType.APPLICATION_PDF);
    header.set(HttpHeaders.CONTENT_DISPOSITION,
                   "attachment; filename=" + fileName.replace(" ", "_"));
    header.setContentLength(documentBody.length);

    return new HttpEntity<byte[]>(documentBody, header);
}

如果你的PDF框架(documentBbody)的返回类型不是一个字节数组(也没有ByteArrayInputStream)，那么它将是明智的不让它成为一个字节数组。相反，最好使用:

InputStreamResource, PathResource(从Spring 4.0开始)或 FileSystemResource,

使用FileSystemResource示例:

@RequestMapping(value = "/files/{fileName}", method = RequestMethod.GET)
public HttpEntity<byte[]> createPdf(
                 @PathVariable("fileName") String fileName) throws IOException {

    File document = this.pdfFramework.createPdf(filename);

    HttpHeaders header = new HttpHeaders();
    header.setContentType(MediaType.APPLICATION_PDF);
    header.set(HttpHeaders.CONTENT_DISPOSITION,
                   "attachment; filename=" + fileName.replace(" ", "_"));
    header.setContentLength(document.length());

    return new HttpEntity<byte[]>(new FileSystemResource(document),
                                  header);
}

我必须加上这个才能下载任何文件

    response.setContentType("application/octet-stream");
    response.setHeader("Content-Disposition",
            "attachment;filename="+"file.txt");

所有的代码:

@Controller
public class FileController {

@RequestMapping(value = "/file", method =RequestMethod.GET)
@ResponseBody
public FileSystemResource getFile(HttpServletResponse response) {

    final File file = new File("file.txt");
    response.setContentType("application/octet-stream");
    response.setHeader("Content-Disposition",
            "attachment;filename="+"file.txt");
    return new FileSystemResource(file);
 }
}

如果这对谁有帮助的话。你可以按照Infeligo给出的答案去做，但只需要在强制下载的代码中添加额外的内容即可。

response.setContentType("application/force-download");

在Spring 3.0中，您可以使用HttpEntity返回对象。如果您使用它，那么您的控制器就不需要HttpServletResponse对象，因此它更容易测试。 除了这个，这个答案是相对等于Infeligo的答案。

如果你的pdf框架的返回值是一个字节数组(阅读我回答的其他返回值的第二部分):

@RequestMapping(value = "/files/{fileName}", method = RequestMethod.GET)
public HttpEntity<byte[]> createPdf(
                 @PathVariable("fileName") String fileName) throws IOException {

    byte[] documentBody = this.pdfFramework.createPdf(filename);

    HttpHeaders header = new HttpHeaders();
    header.setContentType(MediaType.APPLICATION_PDF);
    header.set(HttpHeaders.CONTENT_DISPOSITION,
                   "attachment; filename=" + fileName.replace(" ", "_"));
    header.setContentLength(documentBody.length);

    return new HttpEntity<byte[]>(documentBody, header);
}

如果你的PDF框架(documentBbody)的返回类型不是一个字节数组(也没有ByteArrayInputStream)，那么它将是明智的不让它成为一个字节数组。相反，最好使用:

InputStreamResource, PathResource(从Spring 4.0开始)或 FileSystemResource,

使用FileSystemResource示例:

@RequestMapping(value = "/files/{fileName}", method = RequestMethod.GET)
public HttpEntity<byte[]> createPdf(
                 @PathVariable("fileName") String fileName) throws IOException {

    File document = this.pdfFramework.createPdf(filename);

    HttpHeaders header = new HttpHeaders();
    header.setContentType(MediaType.APPLICATION_PDF);
    header.set(HttpHeaders.CONTENT_DISPOSITION,
                   "attachment; filename=" + fileName.replace(" ", "_"));
    header.setContentLength(document.length());

    return new HttpEntity<byte[]>(new FileSystemResource(document),
                                  header);
}

这段代码可以在jsp上单击链接时自动从spring控制器下载文件。

@RequestMapping(value="/downloadLogFile")
public void getLogFile(HttpSession session,HttpServletResponse response) throws Exception {
    try {
        String filePathToBeServed = //complete file name with path;
        File fileToDownload = new File(filePathToBeServed);
        InputStream inputStream = new FileInputStream(fileToDownload);
        response.setContentType("application/force-download");
        response.setHeader("Content-Disposition", "attachment; filename="+fileName+".txt"); 
        IOUtils.copy(inputStream, response.getOutputStream());
        response.flushBuffer();
        inputStream.close();
    } catch (Exception e){
        LOGGER.debug("Request could not be completed at this moment. Please try again.");
        e.printStackTrace();
    }

}

下面的代码为我生成和下载一个文本文件工作。

@RequestMapping(value = "/download", method = RequestMethod.GET)
public ResponseEntity<byte[]> getDownloadData() throws Exception {

    String regData = "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.";
    byte[] output = regData.getBytes();

    HttpHeaders responseHeaders = new HttpHeaders();
    responseHeaders.set("charset", "utf-8");
    responseHeaders.setContentType(MediaType.valueOf("text/html"));
    responseHeaders.setContentLength(output.length);
    responseHeaders.set("Content-disposition", "attachment; filename=filename.txt");

    return new ResponseEntity<byte[]>(output, responseHeaders, HttpStatus.OK);
}