get post小结

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HTTP简介:

HTTP(Hypertext transfer protocol),先说下着几个单词，Hypertext是超文本(除了HTML外，也可以是带有超链接的XML或JSON),protocol是协议，transfer翻译应该是移交(也可以翻译成传输,运输，还有一个更具体的词是transport)，最开始学校学习Http的所有市面能见到的书籍都翻译成超文本传输协议，Http设计的本身是为了移交和操作资源

Http提供了几种方法访问资源.

Http协议中定义了与服务器之间交互的八个方法:get(获取资源),post(向指定资源提交数据进行处理请求，增加或者更新资源)，put(向指定资源位置上传其最新内容 ),delete(请求服务器删除Request-URI所标识的资源)；

GET和POST异同点

1.可见性,get访问时URL是所有人都可见的，post则是不可见的.

2.长度限制
get和post传递长度都是是没有限制的
之所以有人说get的长度是有限制的,是因为get是放在URL中一起去请求的,浏览器限制了URL的长度导致GET的参数不能太长,大概长读是1 KB;其实HTTP协议对URL的长度进行限制
POST是请求大小是没有限制的，Web服务器会对post请求进行控制,postIIS请求限制为最多为28.6M，get请求IIS限制为2KB,如有需要可根据需求修改长度大小

3.安全性,与 post相比，get的安全性较差，因为所发送的数据是 URL 的一部分(登录的时候提交数据应该没人会用get)，post比get更安全，因为参数不会被保存在浏览器历史或 web 服务器日志中。

4.数据类型,get只允许 ASCII 字符; post传递没有限制，也允许二进制数据。
5 . 编码类型, form的enctype属性为表单控件的内容编码方式,常见有两种: application/x-www-form-urlencoded(默认)和multipart/form-data, 不管get还是post都可以使用者两种编码方式,当表单中含有type=file文件控件的时候发送方式只能使用post,内容编码方式只能使用multipart/part/form-data.
6 . 书签, 缓存 , get请求可以收藏为书签,能被缓存, post不可以被收藏为书签,不可以被缓存
7 . 取值方式 , ASP.NET中对于get请求Request.QueryString取值, 对Post请求使用Request.Form

我们在代码中是如何实现的呢?

#define BASE_URL @"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx?date=20131129&startRecord=1&len=5&udid=1234567890&terminalType=Iphone&cid=213"
//把上面的数字换成两部分 以 ？为分界线
#define URL_POST1 @"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx"
#define URL_POST2 @"date=20131129&startRecord=1&len=5&udid=1234567890&terminalType=Iphone&cid=213"

GET同步 <注意这里使用了MJExtension字典转模型框架>

MJExtension:http://www.jianshu.com/p/bbe7c88d5756

#pragma mark ----------------GET同步--------------
-(IBAction)getTong:(UIButton *)sender{
    // 1 创建URL对象
    NSURL *url = [NSURL URLWithString:BASE_URL];
    
    // 2 创建请求对象
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    
    // 2.1 创建请求方式 (默认是get这一步可以不写)
    [request setHTTPMethod:@"get"];
    
    // 3 创建响应对象(有时会出错)
    NSURLResponse *response= nil;
    
    // 4 创建连接对象(同步)
    NSError *error;
    NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
   
    // http://www.jianshu.com/p/bbe7c88d5756
    NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
    NSNumber *lastUpdateTime = dict[@"lastUpdateTime"];
    NSLog(@"lastUpdateTime = %@",lastUpdateTime);
    NSArray *Array = dict[@"news"];
    self.dataArray = [NewsModel mj_objectArrayWithKeyValuesArray:Array];
    
    for (NewsModel *newsModal in self.dataArray) {
        NSLog(@"newsModal.title = %@",newsModal.title);
    }
}

POST同步

#pragma mark ---------------POST同步-----------------
- (IBAction)postAction1:(UIButton *)sender {
    NSLog(@"Post同步");
    
    //1 创建URL对象
    NSURL *url =[NSURL URLWithString:URL_POST1];
    
    //2 创建请求对象
    NSMutableURLRequest *resuest =[NSMutableURLRequest requestWithURL:url];
    
    //2.1 创建请求方式
    [resuest setHTTPMethod:@"post"];//get可以省略 但是post必须要写
    
    //3 设置请求参数
    NSData *tempData = [URL_POST2 dataUsingEncoding:NSUTF8StringEncoding];
    [resuest setHTTPBody:tempData];//设置请求主体 外界看不见数据
    //4 创建响应对象
    NSURLResponse *response = nil;
    
    //5 创建连接对象
    NSError *error;
    NSData *data = [NSURLConnection sendSynchronousRequest:resuest returningResponse:&response error:&error];
    
    NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:&error];
    
    
    NSNumber *lastUpdateTime = dict[@"lastUpdateTime"];
    NSLog(@"lastUpdateTime = %@",lastUpdateTime);
    NSArray *Array = dict[@"news"];
    self.dataArray = [NewsModel mj_objectArrayWithKeyValuesArray:Array];
    
    for (NewsModel *newsModal in self.dataArray) {
        NSLog(@"newsModal.title = %@",newsModal.title);
    }

}

GET connection异步

#pragma mark ---------------GET connection异步-----------------
-(IBAction)getYibu:(UIButton *)sender{
    
    NSURL *url = [NSURL URLWithString:BASE_URL];
    NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestReloadRevalidatingCacheData timeoutInterval:10];
    //连接服务器
    NSURLConnection *connection = [NSURLConnection connectionWithRequest:request delegate:self];
    [connection start];
    
}


//NSURLConnectionDataDelegate代理方法
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response;
{
    NSLog(@"didReceiveResponse");
    _tempData = [NSMutableData data];

}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data;{
    NSLog(@"didReceiveData");
      [_tempData appendData:data];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection;{
    _dataArray = [NSMutableArray arrayWithCapacity:1];
    
    NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:_tempData options:NSJSONReadingAllowFragments error:nil];
    
    
    NSNumber *lastUpdateTime = dict[@"lastUpdateTime"];
    NSLog(@"lastUpdateTime = %@",lastUpdateTime);
    NSArray *Array = dict[@"news"];
    self.dataArray = [NewsModel mj_objectArrayWithKeyValuesArray:Array];
    
    for (NewsModel *newsModal in self.dataArray) {
        NSLog(@"newsModal.title = %@",newsModal.title);
    }
}

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

GET Session异步

#pragma mark --------------GET Session异步请求-----------------

- (IBAction)getSession:(UIButton *)sender {
    NSURL *url =[NSURL URLWithString:BASE_URL];
    
    //创建session对象
    NSURLSession *session =[NSURLSession sharedSession];
    __weak typeof(self)temp =self;
    //创建task（该方法内部默认使用get）直接进行传递url即可
    NSURLSessionDataTask *dataTask =[session dataTaskWithURL:url completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        
        temp.dataArray = [NSMutableArray arrayWithCapacity:1];
        //数据操作
        NSDictionary *dict =[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:nil];
        
        NSNumber *lastUpdateTime = dict[@"lastUpdateTime"];
        NSLog(@"lastUpdateTime = %@",lastUpdateTime);
        NSArray *Array = dict[@"news"];
        self.dataArray = [NewsModel mj_objectArrayWithKeyValuesArray:Array];
        
        for (NewsModel *newsModal in self.dataArray) {
            NSLog(@"newsModal.title = %@",newsModal.title);
        }
        
        NSLog(@"idStr = %@",self.dataArray[1].type);
        
    }];
    
    //数据操作
    [dataTask resume];
    // 注意数据操作之后无法获得数据
    for (NewsModel *newsModal in self.dataArray) {
        NSLog(@"newsModal.title = %@",newsModal.title);
    }
    
}

POST Session异步请求

#pragma mark -------POST Session异步请求---------

- (IBAction)postSession:(UIButton *)sender {
    //创建URL对象
    NSURL *url =[NSURL URLWithString:URL_POST1];
    //创建请求对象
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    [request setHTTPMethod:@"post"];
    NSData *tempdata = [URL_POST2 dataUsingEncoding:NSUTF8StringEncoding];
    [request setHTTPBody:tempdata];
    // 3 建立会话 session支持三种类型的任务
    
    //    NSURLSessionDataTask  //加载数据
    //    NSURLSessionDownloadTask  //下载
    //    NSURLSessionUploadTask   //上传
    NSURLSession *session =[NSURLSession sharedSession];
    //    NSLog(@"%d",[[NSThread currentThread] isMainThread]);
    
    __weak typeof(self)weakSelf = self;
    
    NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        //解析
        _dataArray = [NSMutableArray arrayWithCapacity:1];
        NSDictionary *dict =[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:nil];
        
        
        NSNumber *lastUpdateTime = dict[@"lastUpdateTime"];
        NSLog(@"lastUpdateTime = %@",lastUpdateTime);
        NSArray *Array = dict[@"news"];
        self.dataArray = [NewsModel mj_objectArrayWithKeyValuesArray:Array];
        
        for (NewsModel *newsModal in weakSelf.dataArray) {
            NSLog(@"newsModal.title = %@",newsModal.title);
        }
        
        NSLog(@"当前的线程为%@",[NSThread currentThread]);
        //回到主线程 刷新数据 要是刷新就在这里面
        dispatch_async(dispatch_get_main_queue(), ^{
            
            for (NewsModel *model in weakSelf.dataArray) {
                NSLog(@"summary = %@",model.summary);
            }
            
        });
    }];
    //启动任务
    [dataTask resume];
}