Question

我是jersey / JAX-RS实施的新手。请在下面找到我的球衣客户代码下载文件：

 Client client = Client.create();
 WebResource wr = client.resource("http://localhost:7070/upload-0.0.1-SNAPSHOT/rest/files/download");
 Builder wb=wr.accept("application/json,application/pdf,text/plain,image/jpeg,application/xml,application/vnd.ms-excel");
 ClientResponse clientResponse= wr.get(ClientResponse.class);
 System.out.println(clientResponse.getStatus());
 File res= clientResponse.getEntity(File.class);
 File downloadfile = new File("C://Data/test/downloaded/testnew.pdf");  
 res.renameTo(downloadfile);
 FileWriter fr = new FileWriter(res);
 fr.flush();

我的服务器端代码是：

@Path("/download")
    @GET
    @Produces({"application/pdf","text/plain","image/jpeg","application/xml","application/vnd.ms-excel"})
    public Response getFile()
    {

        File download = new File("C://Data/Test/downloaded/empty.pdf");
        ResponseBuilder response = Response.ok((Object)download);
        response.header("Content-Disposition", "attachment; filename=empty.pdf");
        return response.build();
    }

在我的客户端代码中，我收到的响应为200 OK，但我无法将文件保存在硬盘上在下面的行中，我提到了需要保存文件的路径和位置。不知道这里出了什么问题，任何帮助都会受到赞赏。谢谢你们提前!!

File downloadfile = new File("C://Data/test/downloaded/testnew.pdf");

Answer 1

我不知道泽西岛是否让你回答一个像你这样的文件：

File download = new File("C://Data/Test/downloaded/empty.pdf");
ResponseBuilder response = Response.ok((Object)download);

你可以当然使用StreamingOutput响应从服务器发送文件，如下所示：

StreamingOutput stream = new StreamingOutput() {
    @Override
    public void write(OutputStream os) throws IOException,
    WebApplicationException {
        Writer writer = new BufferedWriter(new OutputStreamWriter(os));

        //@TODO read the file here and write to the writer

        writer.flush();
    }
};

return Response.ok(stream).build();

并且您的客户希望读取一个流并将其放在一个文件中：

InputStream in = response.getEntityInputStream();
if (in != null) {
    File f = new File("C://Data/test/downloaded/testnew.pdf");

    //@TODO copy the in stream to the file f

    System.out.println("Result size:" + f.length() + " written to " + f.getPath());
}

Answer 2

对于仍在寻找解决方案的人来说，这里有关于如何保存jaxrs响应文件的完整代码。

public void downloadClient(){
    Client client = ClientBuilder.newClient();
    WebTarget target = client.target("http://localhost:7070/upload-0.0.1-SNAPSHOT/rest/files/download");

    Response resp = target
      .request("application/pdf,image/jpeg,application/xml,application/vnd.ms-excel")
      .get();

    if(resp.getStatus() == Response.Status.OK.getStatusCode())
    {
        InputStream is = resp.readEntity(InputStream.class);
        fetchFeed(is); 
        //fetchFeedAnotherWay(is) //use for Java 7
        IOUtils.closeQuietly(is);
        System.out.println("the file details after call:"+downloadfile.getAbsolutePath()+", size is "+downloadfile.length());
    } 
    else{
        throw new WebApplicationException("Http Call failed. response code is"+resp.getStatus()+". Error reported is"+resp.getStatusInfo());
    }
}
/**
* Store contents of file from response to local disk using java 7 
* java.nio.file.Files
*/
private void fetchFeed(InputStream is){
    File downloadfile = new File("C://Data/test/downloaded/testnew.pdf");  
    byte[] byteArray = IOUtils.toByteArray(is);
    FileOutputStream fos = new FileOutputStream(downloadfile);
    fos.write(byteArray);
    fos.flush();
    fos.close();
}

/**
* Alternate way to Store contents of file from response to local disk using
* java 7, java.nio.file.Files
*/
private void fetchFeedAnotherWay(InputStream is){
    File downloadfile = new File("C://Data/test/downloaded/testnew.pdf");  
    Files.copy(is, downloadfile.toPath(), StandardCopyOption.REPLACE_EXISTING);
}

Answer 3

以下示例代码可能对您有所帮助。

https://stackoverflow.com/a/32253028/15789

这是一个JAX RS休息服务和测试客户端。它从文件中读取字节并将字节上载到REST服务。 REST服务压缩字节并将其作为字节发送回客户端。客户端读取字节并保存压缩文件。我发布了这个作为对另一个线程的回复。

Answer 4

这是使用Files.copy（）执行此操作的另一种方法。

    private long downloadReport(String url){

            long bytesCopied = 0;
            Path out = Paths.get(this.fileInfo.getLocalPath());

            try {

                 WebTarget webTarget = restClient.getClient().target(url);
                 Invocation.Builder invocationBuilder = webTarget.request(MediaType.TEXT_PLAIN_TYPE);

                 Response response = invocationBuilder.get();

                 if (response.getStatus() != 200) {
                    System.out.println("HTTP status " response.getStatus());
                    return bytesCopied;
                 }

                 InputStream in = response.readEntity( InputStream.class );
                 bytesCopied = Files.copy(in, out, REPLACE_EXISTING);

                 in.close();

            } catch( IOException e ){
                 System.out.println(e.getMessage());
            }

            return bytesCopied;
     }

Jersey客户端下载并保存文件

4 个答案: