在 iOS 上发送 HTTP POST 请求 [英] Sending an HTTP POST request on iOS
问题描述
我正在尝试使用我正在开发的 iOS 应用程序发送 HTTP Post，但推送从未到达服务器，尽管我确实收到了代码 200 作为响应(来自 urlconnection).我从来没有得到服务器的响应，服务器也没有检测到我的帖子(服务器确实检测到来自 android 的帖子)
I'm trying to send an HTTP Post with the iOS application that I'm developing but the push never reaches the server although I do get a code 200 as response (from the urlconnection). I never get a response from the server nor does the server detect my posts (the server does detect posts coming from android)
我确实使用 ARC，但已将 pd 和 urlConnection 设置为强.
I do use ARC but have set pd and urlConnection as strong.
这是我发送请求的代码
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]
initWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"%@%@",dk.baseURL,@"daantest"]]];
[request setHTTPMethod:@"POST"];
[request setValue:@"text/xml"
forHTTPHeaderField:@"Content-type"];
NSString *sendString = @"<data><item>Item 1</item><item>Item 2</item></data>";
[request setValue:[NSString stringWithFormat:@"%d", [sendString length]] forHTTPHeaderField:@"Content-length"];
[request setHTTPBody:[sendString dataUsingEncoding:NSUTF8StringEncoding]];
PushDelegate *pushd = [[PushDelegate alloc] init];
pd = pushd;
urlConnection = [[NSURLConnection alloc] initWithRequest:request delegate:pd];
[urlConnection start];
这是我的委托代码
#import "PushDelegate.h"
@implementation PushDelegate
@synthesize data;
-(id) init
{
if(self = [super init])
{
data = [[NSMutableData alloc]init];
[data setLength:0];
}
return self;
}
- (void)connection:(NSURLConnection *)connection didWriteData:(long long)bytesWritten totalBytesWritten:(long long)totalBytesWritten
{
NSLog(@"didwriteData push");
}
- (void)connectionDidResumeDownloading:(NSURLConnection *)connection totalBytesWritten:(long long)totalBytesWritten expectedTotalBytes:(long long)expectedTotalBytes
{
NSLog(@"connectionDidResumeDownloading push");
}
- (void)connectionDidFinishDownloading:(NSURLConnection *)connection destinationURL:(NSURL *)destinationURL
{
NSLog(@"didfinish push @push %@",data);
}
- (void)connection:(NSURLConnection *)connection didSendBodyData:(NSInteger)bytesWritten totalBytesWritten:(NSInteger)totalBytesWritten totalBytesExpectedToWrite:(NSInteger)totalBytesExpectedToWrite
{
NSLog(@"did send body");
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
[self.data setLength:0];
NSHTTPURLResponse *resp= (NSHTTPURLResponse *) response;
NSLog(@"got response with status @push %d",[resp statusCode]);
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)d
{
[self.data appendData:d];
NSLog(@"recieved data @push %@", data);
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSString *responseText = [[NSString alloc] initWithData:self.data encoding:NSUTF8StringEncoding];
NSLog(@"didfinishLoading%@",responseText);
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
[[[UIAlertView alloc] initWithTitle:NSLocalizedString(@"Error ", @"")
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:NSLocalizedString(@"OK", @"")
otherButtonTitles:nil] show];
NSLog(@"failed &push");
}
// Handle basic authentication challenge if needed
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{
NSLog(@"credentials requested");
NSString *username = @"username";
NSString *password = @"password";
NSURLCredential *credential = [NSURLCredential credentialWithUser:username
password:password
persistence:NSURLCredentialPersistenceForSession];
[[challenge sender] useCredential:credential forAuthenticationChallenge:challenge];
}
@end
控制台总是打印以下几行并且只打印以下几行:
The console always prints the following lines and the following lines only:
2013-04-01 20:35:04.341 ApprenticeXM[3423:907] did send body
2013-04-01 20:35:04.481 ApprenticeXM[3423:907] got response with status @push 200
2013-04-01 20:35:04.484 ApprenticeXM[3423:907] didfinish push @push <>
推荐答案
下面的代码描述了一个使用 POST 方法的简单例子.(How one can pass data by POST 方法)
The following code describes a simple example using POST method.(How one can pass data by POST method)
在这里，我描述了如何使用 POST 方法.
Here, I describe how one can use of POST method.
1. 使用实际用户名和密码设置帖子字符串.
1. Set post string with actual username and password.
NSString *post = [NSString stringWithFormat:@"Username=%@&Password=%@",@"username",@"password"];
2. 使用 NSASCIIStringEncoding 对 post 字符串以及您需要以 NSData 格式发送的 post 字符串进行编码.
2. Encode the post string using NSASCIIStringEncoding and also the post string you need to send in NSData format.
NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
您需要发送数据的实际长度.计算post字符串的长度.
You need to send the actual length of your data. Calculate the length of the post string.
NSString *postLength = [NSString stringWithFormat:@"%d",[postData length]];
3. 创建一个带有所有属性的 Urlrequest，如 HTTP 方法、带有 post 字符串长度的 http 标头字段.创建 URLRequest 对象并初始化它.
3. Create a Urlrequest with all the properties like HTTP method, http header field with length of the post string. Create URLRequest object and initialize it.
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
设置您要向该请求发送数据的 URL.
Set the Url for which your going to send the data to that request.
[request setURL:[NSURL URLWithString:@"http://www.abcde.com/xyz/login.aspx"]];
现在，设置 HTTP 方法(POST 或 GET).按照代码中的原样编写这些行.
Now, set HTTP method (POST or GET). Write this lines as it is in your code.
[request setHTTPMethod:@"POST"];
设置 HTTP 头字段和 post 数据的长度.
Set HTTP header field with length of the post data.
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
还要设置 HTTP 标头字段的编码值.
Also set the Encoded value for HTTP header Field.
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
使用 postData 设置 urlrequest 的 HTTPBody.
Set the HTTPBody of the urlrequest with postData.
[request setHTTPBody:postData];
4. 现在，创建 URLConnection 对象.使用 URLRequest 对其进行初始化.
4. Now, create URLConnection object. Initialize it with the URLRequest.
NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];
返回初始化的url连接，开始为url请求加载数据.您可以使用如下的 if/else 语句检查您的 URL 连接是否正确完成.
It returns the initialized url connection and begins to load the data for the url request. You can check that whether you URL connection is done properly or not using just if/else statement as below.
if(conn) {
NSLog(@"Connection Successful");
} else {
NSLog(@"Connection could not be made");
}
5. 要从 HTTP 请求接收数据，您可以使用 URLConnection 类参考提供的委托方法.委托方法如下.
5. To receive the data from the HTTP request , you can use the delegate methods provided by the URLConnection Class Reference. Delegate methods are as below.
// This method is used to receive the data which we get using post method.
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData*)data
// This method receives the error report in case of connection is not made to server.
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
// This method is used to process the data after connection has made successfully.
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
Also Refer This and This documentation for POST method.
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