how to use okhttp to upload a file?

Question

I use okhttp to be my httpclient. I think it's a good api but the doc is not so detailed.

how to use it to make a http post request with file uploading?

public Multipart createMultiPart(File file){     Part part = (Part) new Part.Builder().contentType("").body(new File("1.png")).build();     //how to  set part name?     Multipart m = new Multipart.Builder().addPart(part).build();     return m; } public String postWithFiles(String url,Multipart m) throws  IOException{     ByteArrayOutputStream out = new ByteArrayOutputStream();     m.writeBodyTo(out)     ;     Request.Body body =  Request.Body.create(MediaType.parse("application/x-www-form-urlencoded"),             out.toByteArray());      Request req = new Request.Builder().url(url).post(body).build();     return client.newCall(req).execute().body().string();  } 

my question is:

1. how to set part name? in the form, the file should be named file1.
2. how to add other fields in the form?

Answer 1

Here is a basic function that uses okhttp to upload a file and some arbitrary field (it literally simulates a regular HTML form submission)

Change the mime type to match your file (here I am assuming .csv) or make it a parameter to the function if you are going to upload different file types

  public static Boolean uploadFile(String serverURL, File file) {     try {          RequestBody requestBody = new MultipartBody.Builder().setType(MultipartBody.FORM)                 .addFormDataPart("file", file.getName(),                         RequestBody.create(MediaType.parse("text/csv"), file))                 .addFormDataPart("some-field", "some-value")                 .build();          Request request = new Request.Builder()                 .url(serverURL)                 .post(requestBody)                 .build();          client.newCall(request).enqueue(new Callback() {              @Override             public void onFailure(final Call call, final IOException e) {                 // Handle the error             }              @Override             public void onResponse(final Call call, final Response response) throws IOException {                 if (!response.isSuccessful()) {                     // Handle the error                 }                 // Upload successful             }         });          return true;     } catch (Exception ex) {         // Handle the error     }     return false; } 

Note: because it is async call, the boolean return type does not indicate successful upload but only that the request was submitted to okhttp queue.