API 调用缺少文件传输的标头信息

Posted 2023-03-15

【中文标题】API 调用缺少文件传输的标头信息

【英文标题】：API call missing header information for file transfer

【发布时间】：2017-04-05 19:23:11

【问题描述】：

我正在编写一个 java 代码，它将通过 API 调用将文件发送到某个 URL，但是在来自 URL 的 GET 响应期间丢失了一些信息，它看起来像我的文件信息缺少显示名称、文件类型。 display_name 将是我的文件的文件名 这是返回的 JSON 数据

  
   "data_id":"55229f05ab534b08b369c324311e2c99",
   "file_info":  
      "display_name":"",
      "file_size":254,
      "file_type":"Not available",
      "file_type_description":"Not available",
      "md5":"8a0c92123d8ffefd95aa1d3dd239c3f7",
      "sha1":"1cfd579d81df680b64e2127296aac55566b95b59",
      "sha256":"a86758bed1a99e12d301fd8bc90749bef89685b9a9c93ad7fa6ee832cb6a7d4e",
      "upload_timestamp":"2016-11-22T05:12:42.374Z"
   , 

这是我的示例 java 源代码

import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.impl.client.DefaultHttpClient;

    public class SentFile 

    public static void main(String [] args) throws ClientProtocolException, IOException
    
          HttpClient client = new DefaultHttpClient();
          HttpPost post = new HttpPost("http://192.168.0.25:8008/file");
         // File file = new File("testScanFile.txt");
         //FileInputStream fileInputStream = new FileInputStream(file);
          FileBody bin = new FileBody(new File("testScanFile.txt"));
          HttpEntity reqEntity = MultipartEntityBuilder.create()
                   .addPart("bin", bin)
                //   .addPart("file",bin);
                   .build();
           post.addHeader("content-type","application/json");
           post.addHeader("Accept","application/json");
           post.setEntity(reqEntity);
          //InputStream is = new FileInputStream(file);
         // post.setEntity(new FileEntity(file));
          HttpResponse response = client.execute(post);
          BufferedReader rd = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
          String line = "";
          while ((line = rd.readLine()) != null) 
           // System.out.println(line);
           PrintStream ps = new PrintStream(new FileOutputStream("data_id.txt"));
           ps.print(line);
           ps.close();
          
         

    

如果我尝试在 HttpEntity 类下添加 .addPart("file", bin)，它会显示一些错误消息，this 是我的 .addPart 参考链接，但是当我执行了程序，我的编译器显示这个错误

Exception in thread "main" java.lang.Error: Unresolved compilation problems: 
    Type mismatch: cannot convert from MultipartEntityBuilder to HttpEntity
    Syntax error on token ".", delete this token
    The method build() is undefined for the type SentFile 

我也测试了这段代码，没有出现错误，但 display_name 仍然丢失

post.addHeader("content-type","application/json");
post.addHeader("Accept","application/json");

【参考方案1】：

您确实应该发布服务器 API 定义，但是此示例显示了 Apache Fluent API 中的设施：

MultipartEntityBuilder.create()
    .addBinaryBody("bin"                 // Important! Defined by the server 
        , new File("testScanFile.txt")   // Not important, user defined
        , ContentType.APPLICATION_JSON   // Maybe ignored. Depends
        , "testScanFile.txt"             // User defined
).build();

【讨论】：

我测试了您提供的代码，它运行没有错误，但我的显示名称仍然为空

请发布服务器 API 规范

你能给我提供服务器 API 规范的链接吗？谢谢