json object post with servlet

公司最近项目里需要用到post json对象（所谓的json对象我理解的就是一个json字符串），在发送的时候总是有违预期结果，代码如下：

        // 生成json数据
        NSMutableDictionary *jsonDic = [NSMutableDictionary dictionary];
        
        [jsonDic setObject:@"HIHG022648" forKey:@"hotelDerbyPassport"];
        [jsonDic setObject:@"JS" forKey:@"username"];
        
        NSString *strPwd = @"123456";
        NSString *strPwdMD5 = [strPwd md5HexDigest];
        [jsonDic setObject:strPwdMD5 forKey:@"password"];
        
        [jsonDic setObject:@"Jane" forKey:@"firstName"];
        [jsonDic setObject:@"Smith" forKey:@"lastName"];
        
        [jsonDic setObject:@"13333330000" forKey:@"mobilephone"];
        [jsonDic setObject:@"[email protected]" forKey:@"email"];
        NSString *strJson = [jsonDic JSONString];
        NSLog(@"%@",strJson);
        
        NSURL *url = [NSURL URLWithString:@"http://218.xxx.xxx.85/interface/api/member/api_member_register"];
        NSMutableURLRequest *postRequest = [[NSMutableURLRequest alloc] initWithURL:url];
        
        NSMutableString *strPost = [[NSMutableString alloc] initWithString:strJson];
        NSData *postData = [strPost dataUsingEncoding:NSUTF8StringEncoding];
        [strPost release];
        [self httpsEnginePost:postData postRequest:postRequest];
        [postRequest release];
    }

想起以前扒某网站的时候无论怎么搞，得到的数据都不是预期值，后来改了一个header的浏览器类型就ok了=。=，于是加上下面这段代码：

        [postRequest setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];

well done。