Question

我正在使用MultiPartEntity进行HttpPut，通过webHDFS REST API将文件写入HDFS。请求本身经过并给出正确的响应，307和201.但是图像的多部分标题也作为其一部分写入，如下所示，它不是一个有效的图像来检索和打开。

- 8DkJ3RkUHahEaNE9Ktw8NC1TFOqegjfA9Ps
内容处理：表格数据; NAME = “文件”;文件名= “advert.jpg”
内容类型：application / octet-stream

ÿØÿàJFIFHHÿÛC //图像内容的其余部分
--8DkJ3RkUHahEaNE9Ktw8NC1TFOqegjfA9Ps

从图像文件中删除多部分标题，使其成为有效图像，但我不确定如何避免它开始。我甚至不确定我是否可以控制这个，因为webHDFS负责实际编写文件。

这是我的代码。还有其他我应该做的事吗？

final String LOCATION = "Location";
final String writeURI = "http://<ip>:50070/webhdfs/v1/user/hadoop/advert.jpg"; 

HttpPut put = new HttpPut(writeURI);
HttpClient client = HttpClientBuilder.create().build();        
HttpResponse response = client.execute(put);
put.releaseConnection();

String redirectUri = null;
Header[] headers = response.getAllHeaders();
for(Header header : headers)
{
    if(LOCATION.equalsIgnoreCase(header.getName()))
    {
         redirectUri = header.getValue();
    }                    
}

HttpPut realPut = new HttpPut(redirectUri);
realPut.setEntity(buildMultiPartEntity("advert.jpg"));
HttpResponse response2 = client.execute(realPut);


private HttpEntity buildMultiPartEntity(String fileName)
{
   MultipartEntityBuilder multipartEntity = MultipartEntityBuilder.create();
   multipartEntity.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
   multipartEntity.addPart("file", new FileBody(new File(fileName)));
   return multipartEntity.build();
}

感谢任何帮助。

Answer 1

我遇到了与python请求相同的问题。我最后解决的问题是在发送之前将图像读入内存。并使用一步调用webhdfs api而不是两个。希望这会有所帮助。

host_url = current_app.config.get('HDFS_URL', '')
adx_img_path = current_app.config.get('ADX_CUSTOMER_IMAGE', '')
real_path = adx_img_path + remotefile
hdfs_username = current_app.config.get('HDFS_USERNAME', 'xdisk')
parameters = '?user.name=' + hdfs_username + '&op=CREATE&data=true'
img = open(localfile, 'rb').read()
url = host_url + real_path + parameters
r = requests.put(url, data=img, headers={"Content-Type": "application/octet-stream"})

通过将图像读取为二进制/字节，似乎不会将奇怪的标头添加到文件头中。对于您使用的HttpClient，我建议您尝试InputStreamBody或ByteArrayBody。

Answer 2

使用Content-Type＆＃34; application / octet-stream＆＃34;将图像添加为FileEntity，ByteArrayEntity或InputStreamEntity。

Answer 3

这是根据接受的答案为我工作的代码：

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.entity.FileEntity;
import org.apache.http.impl.client.HttpClientBuilder;

import java.io.File;
import java.io.IOException;

public class Test {

    public void Test(){
        try {

            final String writeURI = "http://<IP>:50075/webhdfs/v1/user/sample.xml?op=CREATE&user.name=istvan&namenoderpcaddress=quickstart.cloudera:8020&overwrite=true";

            HttpClient client = HttpClientBuilder.create().build();

            HttpPut put = new HttpPut(writeURI);
            put.setEntity(buildFileEntity("C:\\sample.xml"));
            put.setHeader("Content-Type", "application/octet-stream");
            HttpResponse response = client.execute(put);

            System.out.println(response);

        }catch(IOException e){
            e.printStackTrace();
        }
    }


    private static FileEntity buildFileEntity (String fileName)
    {
        FileEntity inputData = new FileEntity(new File(fileName));

        return inputData;
    }

    public static void main(String[] args) {
        new Test().Test();
    }
}

的Maven：

        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.4</version>
        </dependency>

        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpmime</artifactId>
            <version>4.3.1</version>
        </dependency>

通过webHDFS REST API将映像上载到HDFS的问题

3 个答案: