Question

在我的Spring Controller中，我编写了从resources文件夹返回JSP页面上的图像的方法。但是，如果我更改资源（或）添加新的我的InputStream是null。当我重新加载应用程序时，它再次工作。

如何在不重新加载应用程序的情况下获取图像？

我在控制器中的方法：

@ResponseBody
    @RequestMapping(value = "/image/{authorUsername}/{title}", method = RequestMethod.GET, produces = MediaType.IMAGE_JPEG_VALUE)
    public byte[] testphoto(HttpServletRequest request,
                            @PathVariable("authorUsername") String authorUsername,
                            @PathVariable("title") String title) throws IOException {
        InputStream in = servletContext.getResourceAsStream("/resources/uploadImages/zeus192/" + title + "/0.jpg");
        return IOUtils.toByteArray(in);
    }

JSP页面上的

：

<img src="/image/${advert.authorUsername}/${advert.title}/">

编辑：

    @ResponseBody
    @RequestMapping(value = "/image/{authorUsername}/{title}", method = RequestMethod.GET, produces = MediaType.IMAGE_JPEG_VALUE)
    public void testphoto(HttpServletRequest request, HttpServletResponse response,
                                         @PathVariable("authorUsername") String authorUsername,
                                         @PathVariable("title") String title) throws IOException {

        InputStream instream = servletContext.getResourceAsStream("/resources/uploadImages/zeus192/" + title + "/0.jpg");
        byte[] bytes =  IOUtils.toByteArray(instream);
        int contentLength = IOUtils.copy(new ByteArrayInputStream(bytes), response.getOutputStream());
        response.setContentLength(contentLength);
        response.setHeader("Content-Disposition", "inline;filename=\"" + "0.jpg" + "\"");
    }

已编辑2：

@ResponseBody
@RequestMapping(value = "/image/{authorUsername}/{title}", method = RequestMethod.GET, produces = MediaType.IMAGE_JPEG_VALUE)
public void testphoto(HttpServletRequest request, HttpServletResponse response,
                                     @PathVariable("authorUsername") String authorUsername,
                                     @PathVariable("title") String title) throws IOException {

    String contextPath = request.getSession().getServletContext().getRealPath("");
    String directory = contextPath.substring(0,contextPath.length() - 18) + "/target/YaPokupay/src/main/webapp/resources/uploadImages/" + authorUsername + "/" + title + "/0.jpg";

    File file = new File(directory);
    String filePath = file.getPath(); // D:\Works\YaPokupay\target\YaPokupay\src\main\webapp\resources\uploadImages\zeus192\Картинка\0.jpg
    InputStream instream = this.getClass().getClassLoader().getResourceAsStream(filePath);

    byte[] bytes =  IOUtils.toByteArray(instream);
    int contentLength = IOUtils.copy(new ByteArrayInputStream(bytes), response.getOutputStream());
    response.setContentLength(contentLength);

    response.setHeader("Content-Disposition", "inline;filename=\"" + "0.jpg" + "\"");

}

Answer 1

以下是从Spring controller下载文件的代码。添加httpServletResponse作为参数，并将文件流设置为响应输出流。

   @ResponseBody
    @RequestMapping(value = "/image/{authorUsername}/{title}", method = RequestMethod.GET, produces = MediaType.IMAGE_JPEG_VALUE)
    public void testphoto(HttpServletRequest request,HttpServletResponse response,
                            @PathVariable("authorUsername") String authorUsername,
                            @PathVariable("title") String title) throws IOException {
        InputStream in = servletContext.getResourceAsStream("/resources/uploadImages/zeus192/" + title + "/0.jpg");
        Byte[] bytes =  IOUtils.toByteArray(in);
        int contentLength = IOUtils.copy(new ByteArrayInputStream(bytes), response.getOutputStream());
        httpServletResponse.setContentLength(contentLength);
    }

如果您想在浏览器中呈现图片，请添加标题＆＃34; Content-Disposition＆＃34;作为内联其他附件，将文件下载到本地计算机。

if(inline){  // if you want to attachment to be inline
    response.setHeader("Content-Disposition", "inline;filename=\"" + fileName + "\"");
}else{
    response.setHeader("Content-Disposition", "attachment;filename=\"" + fileName + "\"");
}

Answer 2

这适用于我对同一资源的多个请求。我的资源位于（../ ProjectName / src / main / webapp / resources / images / logos）

@Autowired
private ServletContext servletContext;

@RequestMapping(value = "/sampleJavaOperation", method = RequestMethod.GET)
    public void sampleJavaOperation(HttpServletRequest request, HttpServletResponse response) throws IOException {

        InputStream instream = servletContext.getResourceAsStream("/resources/images/logos/wavemaker_62x62.png");
        byte[] bytes =  IOUtils.toByteArray(instream);
        int contentLength = IOUtils.copy(new ByteArrayInputStream(bytes), response.getOutputStream());
        response.setContentLength(contentLength);
        response.setHeader("Content-Disposition", "inline;filename=\"" + "0.png" + "\"");
    }

如何在没有重新加载应用程序的情况下在Spring控制器上传后获取图像？

2 个答案: