SOAP-XML请求(iOS应用下集成携程api)

用携程机票为例: 携程联盟 飞机票、门票 联盟ID：278639 站点ID：739462 密钥KEY：BE57B925-E8CE-4AA2-AC8E-3EE4BBBB686F API_URL：openapi.ctrip.com http://open.ctrip.com/InlandFlight/OTA_FlightSearch.aspx

1.首先在使用携程api的时候你需要明白什么是soap？

SOAP(SimpleObjectaccessPRotocal，简单对象访问协议)技术有助于实现大量异构程序和平台之间的互操作性，从而使存在的应用能够被广泛的用户所访问。SOAP是把成熟的基于HTTP的WEB技术与xml的灵活性和可扩展性组合在了一起。

2.作为ios开发者，当我们请求时需要xml格式的请求体就比较蛋疼了。今天带大家先简单看看soap，简单对象访问协议，或者叫做简单交换协议。我的理解就是我们在请求的时候发一个请求，这个请求带上xml格式请求体。然后呢，服务器在接受到我们xml请求体后，返回给我们一个xml结果。然后我们开始解析。就是这样的一个请求的过程。

3.那么有些同学可能会问了，怎么封装xml请求体呢？

NSString *soapBody =  [NSString stringWithFormat:@"<?xml version=\"1.0\" encoding=\"utf-8\"?>"

"<soap:Envelope xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\">"

"<soap:Body>"

//------下面是xml-----//

"<Request>"

"<Header AllianceID=\"278639\" SID=\"739462\" TimeStamp=\"1450326295\" Signature=\"4639A23E98A9141EFFC639F483828C3C\" RequestType=\"OTA_FlightSearch\" AsyncRequest=\"false\" Timeout=\"0\" MessagePriority=\"3\"/>"

"<HotelRequest>"

"<RequestBody xmlns:ns=\"http://www.opentravel.org/OTA/2003/05\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\">"

"<FlightSearchRequest>"

"<SearchType>%@</SearchType>"

"<Routes>"

"<FlightRoute>"

"<DepartCity>%@</DepartCity>"

"<ArriveCity>%@</ArriveCity>"

"<DepartDate>%@</DepartDate>"

"</FlightRoute>"

"</Routes>"

"<PriceTypeOptions>"

"</PriceTypeOptions>"

"<ProductTypeOptions>Normal</ProductTypeOptions>"

"<Classgrade>%@</Classgrade>"

"</FlightSearchRequest>"

"</RequestBody>"

"</HotelRequest>"

"</Request>"

//-----以上部分是xml-------//

"</soap:Body>"

"</soap:Envelope>",SearchType,DepartCity,ArriveCity,DepartDate,Classgrade];

4.那怎样post给服务器呢？

我们平常所说的xml请求体就是一个data，NSData,首先我们需要将字符串转换成为data，然后post给服务器。这样服务器在收到请求后就会回应我们。

//API_URL,接口地址

NSURL *url = [NSURL URLWithString:@"http://openapi.ctrip.com/Flight/DomesticFlight/OTA_FlightSearch.asmx"];

NSMutableURLRequest *request=[NSMutableURLRequest requestWithURL:url];

NSString *msgLength = [NSString stringWithFormat:@"%lu", (unsigned long)[soapBody length]];

[request addValue:@"text/xml; charset=utf-8" forHTTPHeaderField:@"Content-Type"];

[request addValue: @"http://ctrip.com/Request" forHTTPHeaderField:@"SOAPAction"];

[request addValue: msgLength forHTTPHeaderField:@"Content-Length"];

[request setHTTPMethod:@"POST"];

[request setHTTPBody:[soapBody dataUsingEncoding:NSUTF8StringEncoding]];

NSURLConnection *connection=[[NSURLConnection alloc] initWithRequest:request delegate:self];

if (connection) {

NSLog(@"机票查询成功了");

}    [connection start];

//5.设置代理<NSURLConnectionDelegate>,实现代理

/**

*  请求成功后返回的data

*

*  @param connection connection

*  @param data       数据

*/

- (void)connection:(NSURLConnection*)connection didReceiveData:(NSData*)data{

NSLog(@"%@",data);

NSString* strPartData=[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

NSLog(@"=== %@", strPartData);

[self.strReceivedData appendString:strPartData];

}

6.开始解析,#import "GDataXMLNode.h"

- (void)connectionDidFinishLoading:(NSURLConnection *)connection{

NSLog(@"%@ connectionDidFinish.\n",self);

//通过字符串内容创建，GDataXMLDocument实例

NSError*error = nil;

GDataXMLDocument *doc = [[GDataXMLDocument alloc]initWithXMLString:self.strReceivedData options:0 error:&error];

if(error)

{

NSLog(@"Create GDataXMLDocument error,error code: %@",[error localizedDescription]);

return;

}

//首先查找到根元素

GDataXMLElement *rootElement = [doc rootElement];

//在根元素里面查找所有NAME为“Student"的子元素

}