Question

我正在尝试将此POST请求发送到Objective-C中的指定网站，但对HTML以及如何格式化我的请求知之甚少。

如果您想查看我从哪里获取此HTML源代码，地址为：https://selfservice.mypurdue.purdue.edu/prod/bwckgens.p_proc_term_date。

    <FORM ACTION="/prod/bwckschd.p_get_crse_unsec" METHOD="POST">
<INPUT TYPE="hidden" NAME="term_in" VALUE="201320">
<INPUT TYPE="hidden" NAME="sel_subj" VALUE="CS">
<INPUT TYPE="hidden" NAME="sel_levl" VALUE="dummy">
<INPUT TYPE="hidden" NAME="sel_schd" VALUE="dummy">
<INPUT TYPE="hidden" NAME="sel_coll" VALUE="dummy">
<INPUT TYPE="hidden" NAME="sel_divs" VALUE="dummy">
<INPUT TYPE="hidden" NAME="sel_dept" VALUE="dummy">
<INPUT TYPE="hidden" NAME="sel_attr" VALUE="dummy">
   </FORM>

我正在尝试向地址https://selfservice.mypurdue.purdue.edu/prod/bwckctlg.p_display_courses发送POST请求，其中字段“term_in”等于201320，“sel_subj”字段等于“CS”，其余为虚拟。我该怎么做呢？

这是我到目前为止所做的：

#import "PCFViewController.h"

@interface PCFViewController ()

@end

NSMutableData *mutData;

@implementation PCFViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)queryServer {
    NSURL *url = [NSURL URLWithString:@"https://selfservice.mypurdue.purdue.edu/prod/bwckschd.p_get_crse_unsec"];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLCacheStorageNotAllowed timeoutInterval:3.0];
    [request setHTTPMethod:@"POST"];
    NSString *args = @"term_in=201320&sel_subj=CS&sel_day=dummy&sel_schd=dummy&sel_insm=dummy&sel_camp=dummy&sel_levl=dummy&sel_sess=dummy&sel_instr=dummy&sel_ptrm=dummy&sel_attr=dummy";
    NSData *requestBody = [args dataUsingEncoding:NSUTF8StringEncoding];
    [request setValue:@"text/html" forHTTPHeaderField:@"Content-Type"];
    [request setHTTPBody:requestBody];
    NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
    [connection start];
    if (connection) {
        mutData = [NSMutableData data];
    }
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
     NSLog(@"Succeeded! Received %d bytes of data",[mutData length]);
    NSString *str = [[NSString alloc] initWithData:mutData encoding:NSUTF8StringEncoding];
    NSLog(@"%@", str);
}

-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    NSLog(@"%@\n", error.description);
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    [mutData setLength:0];
    NSLog(@"%@\n", response.description);

}

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    [mutData appendData:data];
}
@end

我的控制台向我显示了这个输出：

Succeeded! Received 213 bytes of data
2012-10-25 02:25:38.683 Purdue Course Finder[25844:c07] <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>410 Gone</title>
</head><body>
<h1>Gone</h1>
/prod/bwckschd.p_get_crse_unsechas been permanently removed from this server.</p>
</body></html>

有人可以帮我弄清楚为什么这不是一个有效的请求？如果将值设置为dummy，我是否应该将其添加到字符串中？字符串是否格式不正确，每个值后缀为＆amp;？有什么建议？有人能告诉我这个POST请求的URL，以便我可以适当地修改我的代码吗？

Answer 1

您需要提供字段及其值作为请求的正文，并设置内容类型：

NSString *paramString = [NSString stringWithFormat:@"arg1=%@&arg2=%@", val1, val2];
NSData  *data = [paramString dataUsingEncoding:NSUTF8StringEncoding];
[request setHTTPBody:data];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];

然后执行您的请求。

Answer 2

以这种格式试用，

[request setValue:@"201320" forHTTPHeaderField:@"term_in"];
[request setValue:@"CS" forHTTPHeaderField:@"sel_subj"];
[request setValue:@"dummy" forHTTPHeaderField:@"sel_levl"];

Answer 3

@try this code

NSURL *url = [NSURL URLWithString:@"https://selfservice.mypurdue.purdue.edu/prod/bwckctlg.p_display_courses"];  

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLCacheStorageNotAllowed timeoutInterval:3.0];

[request setHTTPMethod:@"POST"];

NSString *args = @"term_in=201320,sel_subj=CS,sel_levl=dummy,sel_schd=dummy,sel_coll=dummy"sel_divs=dummy,sel_dept=dummy,sel_attr=dummy";

NSData *requestBody = [args dataUsingEncoding:NSUTF8StringEncoding];

[request setHTTPBody:requestBody];

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

使用NSURLConnectionDelegate方法处理响应或错误

对网站Objective-C的POST请求

3 个答案: