How to send multipart POST request using HttpURLConnection in java?

Question

It\'s my first time sending multipart requests and after digging here, I got even more confused so any help regarding the \"correct\" way will be very appriciated.

I

Answer 1

The sample HTML form:

<form method="post" action="http://127.0.0.1/app" enctype="multipart/form-data">
<input type="text" name="foo" value="bar"><br>
<input type="file" name="bin"><br>
<input type="submit" value="test">
</form>

Java code for submiting the multipart form:

    MultipartEntityBuilder mb = MultipartEntityBuilder.create();//org.apache.http.entity.mime
    mb.addTextBody("foo", "bar");
    mb.addBinaryBody("bin", new File("testFilePath"));
    org.apache.http.HttpEntity e = mb.build();

    URLConnection conn = new URL("http://127.0.0.1:8080/app").openConnection();
    conn.setDoOutput(true);
    conn.addRequestProperty(e.getContentType().getName(), e.getContentType().getValue());//header "Content-Type"...
    conn.addRequestProperty("Content-Length", String.valueOf(e.getContentLength()));
    OutputStream fout = conn.getOutputStream();
    e.writeTo(fout);//write multi part data...
    fout.close();
    conn.getInputStream().close();//output of remote url