使用NSMutableURLRequest发送json数据

使用苹果自带的类NSMutableURLRequest post发送数据
使用苹果自带的类NSJSONSerialization解析数据
省去使用第三方库带来的烦恼

//传送json数据
- (IBAction)sendJsonData:(id)sender
{

// NSURL *url = [[NSURL alloc] initWithString:@"http://tianjianweisai.xicp.net:9090/CloserWebService/servlet/LoginServlet"];

NSURL *url = [[NSURL
alloc]
initWithString:@"http://192.168.0.210:8080/CloserWebService/servlet/LoginServlet"];

//创建一个请求,用于发送

NSMutableURLRequest *request = [[NSMutableURLRequest
alloc]
initWithURL:url];

assert(request !=
nil);

[request setTimeoutInterval:5.0f];

NSString *name = @"smile";

NSString *age = @"17";
//使用苹果自带的类NSJSONSerialization生成json

NSDictionary *dict = [[NSDictionary
alloc] initWithObjectsAndKeys:name,@"username",age,@"password",nil];

NSData *jsonData = [NSJSONSerialization
dataWithJSONObject:dict options:NSJSONWritingPrettyPrinted
error:nil];

//下面的二次转换很重要，因为使用NSJSONSerialization生成的data不能直接传给服务端，服务端必须要根据一个名字来读取数据，下面就是给jsonData格式化并取个名称

NSString *strData = [[NSString
alloc]
initWithData:jsonData
encoding:NSASCIIStringEncoding];

NSLog(@"strData:%@",strData);

NSString *postData = [[NSString
alloc] initWithFormat:@"message%@",strData];

NSData *sendData = [postData
dataUsingEncoding:NSASCIIStringEncoding
allowLossyConversion:YES]; //这个sendData才可以发送给服务端

NSString *postLength = [NSString
stringWithFormat:@"%d", [sendData
length]];

[request
setHTTPMethod:@"POST"];
[request
setValue:postLength
forHTTPHeaderField:@"Content-Length"];

[request setValue:@"application/x-www-form-urlencoded"
forHTTPHeaderField:@"Content-Type"];
[request
setHTTPBody:sendData];
//使用NSURLConnection的类方法sendSynchronousRequest:request发送数据

[NSURLConnection
sendSynchronousRequest:request returningResponse:nil
error:nil];

NSHTTPURLResponse* urlResponse =
nil;

NSError *error = [[NSError
alloc] init];

NSData *responseData = [NSURLConnection
sendSynchronousRequest:request
returningResponse:&urlResponse error:&error];

}