My requirement was to upload a file and pass some JSON in an API in Java. So I googled and found some code as below:
When I used this code then I got 400 error with reason as "Bad Request" and empty response body. The target server was also in my control and was running Jersey framework on Tomcat. I checked the logs and found just error as 400. Absolutely no message or other info on the reason of the error.
When I ran the API from CURL then it worked with no issues. Thats makes me believe that the issue is in code above.
After a lot of hit and trial I found that the missing piece is the "boundary". Boundary was not added into the "content-type" header. I changed the code above to:
Thats it ! Code started working. Later I changed the boundary to be generated dynamically instead of being static.
HttpClient httpclient = new DefaultHttpClient(); HttpPost httpPost = new HttpPost(UPLOAD_URI); MultipartEntityBuilder builder = MultipartEntityBuilder.create(); builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE); builder.setCharset(Charset.defaultCharset()); String text = "{\"name\":\"manish\",\"occupation\":\"engineer\"}"; builder.addTextBody("info", text); builder.addPart("doc", new FileBody(file));httpPost.addHeader("content-type", MediaType.MULTIPART_FORM_DATA);httpPost .setEntity(builder.build()); httpclient.execute(httpPost);
When I used this code then I got 400 error with reason as "Bad Request" and empty response body. The target server was also in my control and was running Jersey framework on Tomcat. I checked the logs and found just error as 400. Absolutely no message or other info on the reason of the error.
When I ran the API from CURL then it worked with no issues. Thats makes me believe that the issue is in code above.
After a lot of hit and trial I found that the missing piece is the "boundary". Boundary was not added into the "content-type" header. I changed the code above to:
HttpClient httpclient = new DefaultHttpClient(); HttpPost httpPost = new HttpPost(UPLOAD_URI); MultipartEntityBuilder builder = MultipartEntityBuilder.create(); builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE); builder.setCharset(Charset.defaultCharset()); String text = "{\"name\":\"maniildersh\",\"occupation\":\"engineer\"}";
builder.setBoundary("------------------------f8ee5b62c27a1db3");
builder.addTextBody("info", text); builder.addPart("doc", new FileBody(file));httpPost.addHeader("content-type", MediaType.MULTIPART_FORM_DATA+ "; boundary=------------------------f8ee5b62c27a1db3");httpPost .setEntity(builder.build()); httpclient.execute(httpPost);
Thats it ! Code started working. Later I changed the boundary to be generated dynamically instead of being static.
