Import PBIX via Postman

I was able to get Fiddler to work and used that to fix my Java version. I've included the script below (thanks to Zhang)

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Date;

import org.apache.http.Header;
import org.apache.http.HttpEntity;
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.ContentType;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.impl.client.HttpClientBuilder;


public class ImportPBIXUtil {
 public static void main( String[] args ) {
   try {
     Import();
   } catch ( UnsupportedOperationException e ) {
     // TODO Auto-generated catch block
     e.printStackTrace();
   } catch ( IOException e ) {
     // TODO Auto-generated catch block
     e.printStackTrace();
   }
 }
public static void Import() throws UnsupportedOperationException, IOException {
        String bearer = "Bearer {token}";        
        String fileName = "myReport.pbix";
        String filePath = "C:\\Users\\JohnDoe\\Documents\\PowerBI\\" + fileName;
        String groupId = "{group_id}";

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

        HttpPost post = new HttpPost( "https://api.powerbi.com/v1.0/myorg/groups/" + groupId + "/imports?datasetDisplayName=MyNewReport" );

        long time = (new Date()).getTime();
        String boundary = "---------------------------" + time;
        post.setHeader( "ContentType", "multipart/form-data; boundary=" + boundary );
        post.setHeader( "Authorization", bearer );

        MultipartEntityBuilder builder = MultipartEntityBuilder.create();
        builder.setBoundary( boundary );
        builder.addBinaryBody( "filename", new File( filePath ), ContentType.APPLICATION_OCTET_STREAM, fileName );
        HttpEntity multipart = builder.build();

        post.setEntity( multipart );
        HttpResponse response = null;

        System.out.println( "Request: " );
        for (Header header : post.getAllHeaders()) {
            System.out.println( header.getName() + " : " + header.getValue() );
        }
        
        System.out.println( post.getEntity().getContentLength() );
        
        /*/
        BufferedReader reqd = new BufferedReader( new InputStreamReader( post.getEntity().getContent() ) );

        StringBuffer bbody = new StringBuffer();
        String l = "";
        while ( (l = reqd.readLine()) != null ) {
            bbody.append( l );
        }
        System.out.println( bbody.toString() );
        /*/
        
        System.out.println( "Response: " );
        try {
            response = request.execute( post );
        } catch ( ClientProtocolException e ) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch ( IOException e ) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        BufferedReader rd = new BufferedReader( new InputStreamReader( response.getEntity().getContent() ) );

        StringBuffer result = new StringBuffer();
        String line = "";
        while ( (line = rd.readLine()) != null ) {
            result.append( line );
        }
        System.out.println( response.getStatusLine().getStatusCode() );
        System.out.println( result.toString() );

        return;
  }
}