java - Spring REST 返回 PDF - 响应状态 406( Not Acceptable )

Question

我在 SO 上阅读了很多关于此类问题的问题，但他们都建议使用正确的 Jackson 版本。这是我的现状:

REST API:

@RequestMapping(value = "get/pdf/{id}", headers="Accept=*/*", method = RequestMethod.GET, produces = "application/pdf")
    @Override
    public ResponseEntity<InputStream> getPdfContractById(@PathVariable("id") Long id);

使用 Accept:*/* 会在映射请求时产生错误(发生 404)

来 self 的 pom:

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.4.1</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.4.1.1</version>
    </dependency>

我也尝试添加这两个依赖，但没有任何变化:

    <dependency>
        <groupId>org.codehaus.jackson</groupId>
        <artifactId>jackson-core-asl</artifactId>
        <version>1.9.13</version>
    </dependency>
    <dependency>
        <groupId>org.codehaus.jackson</groupId>
        <artifactId>jackson-mapper-asl</artifactId>
        <version>1.9.13</version>
    </dependency>

响应客户端:出现意外错误(type=Not Acceptable，status=406)。 header 包括:

    Accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Encoding:gzip, deflate, sdch

这是怎么回事？

---

更多详情

我正在使用此代码返回远程 PDF 文件:

    URL url = null;
    try {
        url = new URL(urlStr);
    } catch (MalformedURLException e) {
        e.printStackTrace();
        throw new MyException(e.getMessage());
    }
    InputStream pdfFile = null;
    try {
        pdfFile = url.openStream();
    } catch (IOException e) {
        e.printStackTrace();
        throw new MyException(e.getMessage());
    }

    ResponseEntity<InputStream> re = ResponseEntity
            .ok()
                    //     .headers(headers)
                    //     .contentLength(contentLength)
            .contentType(
                    MediaType.parseMediaType("application/pdf"))
            .body(pdfFile);
   return re;

Answer 1

基本上没有必要在 RequestMapping 中添加 produces = "application/pdf" 因为它似乎试图在内部转换 ResponeBody。您只需将 MediaType 添加到您需要的响应 header 即可。

@ResponseBody
@RequestMapping(value = "get/pdf/{id}", headers="Accept=*/*", method = RequestMethod.GET)
public ResponseEntity<InputStreamResource> getPdfContractById(@PathVariable("id") Long id){
        // Get the remove file based on the fileaddress
        RemoteFile remotefile = new RemoteFile(id);

        // Set the input stream
        InputStream inputstream = remotefile.getInputStream();
        // asume that it was a PDF file
        HttpHeaders responseHeaders = new HttpHeaders();
        InputStreamResource inputStreamResource = new InputStreamResource(inputStream);
        responseHeaders.setContentLength(contentLengthOfStream);
        responseHeaders.setContentType(MediaType.valueOf("application/pdf"));
        // just in case you need to support browsers
        responseHeaders.put("Content-Disposition", Collections.singletonList("attachment; filename=somefile.pdf"))
        return new ResponseEntity<InputStreamResource> (inputStreamResource,
                                   responseHeaders,
                                   HttpStatus.OK);
}