springboot提供 applicatio/pdf接口 httpclient 调用下载

springboot提供 applicatio/pdf接口 httpclient 调用下载

1. springboot 提供下载接口

 @PostMapping(value = "/pdf", produces = MediaType.APPLICATION_PDF_VALUE)
    public String downloadFile(HttpServletRequest request,
                               HttpServletResponse response) throws UnsupportedEncodingException {

        
            File file = new File("D://1.pdf");

            // 如果文件名存在，则进行下载
            if (file.exists()) {

                // 配置文件下载
                response.setHeader("content-type", "application/pdf");
                response.setContentType("application/pdf");
                // 下载文件能正常显示中文
                response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode("1.pdf", "UTF-8"));

                // 实现文件下载
                byte[] buffer = new byte[1024];
                FileInputStream fis = null;
                BufferedInputStream bis = null;
                try {
                    fis = new FileInputStream(file);
                    bis = new BufferedInputStream(fis);
                    OutputStream os = response.getOutputStream();
                    int i = bis.read(buffer);
                    while (i != -1) {
                        os.write(buffer, 0, i);
                        i = bis.read(buffer);
                    }
                    System.out.println("Download the  successfully!");
                } catch (Exception e) {
                    System.out.println("Download the  failed!");
                } finally {
                    if (bis != null) {
                        try {
                            bis.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    if (fis != null) {
                        try {
                            fis.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        
        return null;
    }

2. httpUtil 调用 下载

 public static void main(String[] args) throws IOException {
        HttpClient client = new HttpClient();
        PostMethod postMethod = new PostMethod("http://localhost:8080/pdf");


        client.executeMethod(postMethod);
        NameValuePair[] parameters = postMethod.getParameters();
        System.out.println(parameters[0]);
        InputStream in = postMethod.getResponseBodyAsStream();
        File file = new File("D://3453.pdf");

        try{
            FileOutputStream fout =new FileOutputStream(file);
            int l = -1;
            byte[] tmp =new byte[1024];
            while((l = in.read(tmp)) != -1) {
                fout.write(tmp,0, l);
            }
            fout.flush();
            fout.close();
        }finally{
            // 关闭低层流。
            in.close();
        }
    }
    ```