How can I send a multipart HTTP request on iOS? - ios

Question

I am trying to upload a photo onto a server on my iOS App using multipart method. However, I can't seem to get it to work. I am getting the error:
At least one of the pre-conditions you specified did not hold. Bucket POST must be of the enclosure-type multipart. I've looked this error and can't seem to figure out how I can solve this problem on my end. The Android version of the app works so the API should not be the problem?
Here is my code:
//photo file
NSData *data = [[NSFileManager defaultManager] contentsAtPath:filePath];
NSMutableDictionary* _params = [[NSMutableDictionary alloc] init];
[_params setObject:uploadInfo.key forKey:#"key"];
[_params setObject:uploadInfo.aaki forKey:#"AWSAccessKeyId"];
[_params setObject:uploadInfo.acl forKey:#"acl"];
[_params setObject:uploadInfo.policy forKey:#"policy"];
[_params setObject:uploadInfo.signature forKey:#"signature"];
[_params setObject:uploadInfo.success_action_status forKey:#"success_action_status"];
[_params setObject:#"image/jpeg" forKey:#"Content-Type"];
NSURL* requestURL = [NSURL URLWithString:uploadInfo.path];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];
[request setHTTPShouldHandleCookies:NO];
[request setTimeoutInterval:30];
[request setHTTPMethod:#"POST"];
NSMutableData *body = [NSMutableData data];
for (NSString *param in _params) {
[body appendData:[[NSString stringWithFormat:#"%#", [_params objectForKey:param]] dataUsingEncoding:NSUTF8StringEncoding]];
}
if (data) {
[body appendData:data];
}
[request setHTTPBody:body];
[request setURL:requestURL];
NSURLResponse * response = nil;
NSError * error = nil;
NSData * data1 = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
NSString *responseString = [[NSString alloc] initWithData:data1 encoding:NSUTF8StringEncoding];
NSLog(#"%#",responseString);

Answer 1

Try as below.
//photo file
NSData *data = [[NSFileManager defaultManager] contentsAtPath:filePath];
NSMutableDictionary* _params = [[NSMutableDictionary alloc] init];
[_params setObject:uploadInfo.key forKey:#"key"];
[_params setObject:uploadInfo.aaki forKey:#"AWSAccessKeyId"];
[_params setObject:uploadInfo.acl forKey:#"acl"];
[_params setObject:uploadInfo.policy forKey:#"policy"];
[_params setObject:uploadInfo.signature forKey:#"signature"];
[_params setObject:uploadInfo.success_action_status forKey:#"success_action_status"];
NSURL* requestURL = [NSURL URLWithString:uploadInfo.path];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];
[request setHTTPShouldHandleCookies:NO];
[request setTimeoutInterval:30];
[request setHTTPMethod:#"POST"];
//Create boundary, it can be anything
NSString *boundary = #"------VohpleBoundary4QuqLuM1cE5lMwCy";
// set Content-Type in HTTP header
NSString *contentType = [NSString stringWithFormat:#"multipart/form-data; boundary=%#", boundary];
[request setValue:contentType forHTTPHeaderField: #"Content-Type"];
NSMutableData *body = [NSMutableData data];
for (NSString *param in _params) {
[body appendData:[[NSString stringWithFormat:#"--%#\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"%#\"\r\n\r\n", param] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"%#\r\n", [_params objectForKey:param]] dataUsingEncoding:NSUTF8StringEncoding]];
}
NSString *FileParamConstant = #"image"; // Key of webservice in which you need to send image
// add image data
if (data) {
[body appendData:[[NSString stringWithFormat:#"--%#\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"%#\"; filename=\"image.jpg\"\r\n", FileParamConstant] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[#"Content-Type: image/jpeg\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:data];
[body appendData:[[NSString stringWithFormat:#"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
}
//Close off the request with the boundary
[body appendData:[[NSString stringWithFormat:#"--%#--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[request setHTTPBody:body];
// set the content-length
NSString *postLength = [NSString stringWithFormat:#"%lu", (unsigned long)[body length]];
[request setValue:postLength forHTTPHeaderField:#"Content-Length"];
[request setURL:requestURL];
NSURLResponse * response = nil;
NSError * error = nil;
NSData * data1 = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

Answer 2

Try with another simple code.
NSDictionary *aParams =#{}; //your param dictionary here
UIImage *aImage = [UIImage imageNamed:#"your image here"]; //set yout image here
NSString *aStrParamName = #"image parameter name here";// set parameter name of image here
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:#"uploadInfo.path"]];// url here
[request setHTTPMethod:#"POST"];
[request setTimeoutInterval:30];
NSString *uuidStr = [[NSUUID UUID] UUIDString];
[request addValue:[NSString stringWithFormat:#"multipart/form-data; boundary=%#", uuidStr] forHTTPHeaderField:#"Content-Type"];
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration];
NSData *imagedata = UIImageJPEGRepresentation(aImage, (CGFloat)0.6);
NSData *fileData = UIImagePNGRepresentation([UIImage imageWithData:imagedata]);
NSData *data = [self createBodyWithBoundary:uuidStr withDictData:aParams data:fileData filename:aStrParamName];
NSURLSessionUploadTask *task = [session uploadTaskWithRequest:request fromData:data completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
NSAssert(!error, #"%s: uploadTaskWithRequest error: %#", __FUNCTION__, error);
// parse and interpret the response `NSData` however is appropriate for your app
NSString *aStr = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"ResponseString:%#",aStr);
NSMutableDictionary *aMutDict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(#"responce:%#",aMutDict);
});
}];
[task resume];
also add below method
- (NSData *)createBodyWithBoundary:(NSString *)boundary withDictData:(NSDictionary *)aDict data:(NSData*)data filename:(NSString *)paramName
{
NSMutableData *body = [NSMutableData data];
if (data) {
//only send these methods when transferring data as well as username and password
[body appendData:[[NSString stringWithFormat:#"--%#\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"%#\"; filename=\"%#\"\r\n", paramName,#"image.png"] dataUsingEncoding:NSUTF8StringEncoding]];
#warning if you have to chane name of image then change. if there is any error then chane other wise go as it is..
[body appendData:[[NSString stringWithFormat:#"Content-Type: %#\r\n\r\n", #"image/png"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:data];
[body appendData:[#"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
}
for (NSString *aKey in aDict.allKeys) {
[body appendData:[[NSString stringWithFormat:#"--%#\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:#"Content-Disposition: form-data; name=\"%#\"\r\n\r\n%#\r\n", aKey,aDict[aKey]] dataUsingEncoding:NSUTF8StringEncoding]];
}
[body appendData:[[NSString stringWithFormat:#"--%#--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
return body;
}