NSURLConnection发送GET请求

 //  ViewController.m
 //  04-掌握-NSURLConnection发送GET请求
 //
 //  Created by xiaomage on 16/2/22.
 //  Copyright © 2016年 小码哥. All rights reserved.
 //

 #import "ViewController.h"

 @interface ViewController ()<NSURLConnectionDataDelegate>
 /** 注释 */
 @property (nonatomic, strong) NSMutableData *resultData;
 @end

 @implementation ViewController

 #pragma mark ----------------------
 #pragma mark lazy loading
 -(NSMutableData *)resultData
 {
     if (_resultData == nil) {
         _resultData = [NSMutableData data];
     }
     return _resultData;
 }
 #pragma mark ----------------------
 #pragma mark Events
 -(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
 {
     [self delegate];
 }

 /*
  请求:请求头(NSURLRequest默认包含)+请求体(GET没有)
  响应:响应头(真实类型--->NSHTTPURLResponse)+响应体(要解析的数据)
  */
 #pragma mark ----------------------
 #pragma mark Methods
 -(void)sync
 {
     /*
      GET:http://120.25.226.186:32812/login?username=123&pwd=456&type=JSON
      协议+主机地址+接口名称+?+参数1&参数2&参数3
      post:http://120.25.226.186:32812/login
      协议+主机地址+接口名称
      */
     //GET,没有请求体
     //1.确定请求路径
     NSURL *url = [NSURL URLWithString:@"http://120.25.226.186:32812/login?username=520it&pwd=520it&type=JSON"];

     //2.创建请求对象
     //请求头不需要设置(默认的请求头)
     //请求方法--->默认为GET
     NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url];

     //3.发送请求
     //真实类型:NSHTTPURLResponse
     NSHTTPURLResponse *response = nil;
     /*
      第一个参数:请求对象
      第二个参数:响应头信息
      第三个参数:错误信息
      返回值:响应体
      */
     //该方法是阻塞的,即如果该方法没有执行完则后面的代码将得不到执行
     NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:nil];

     //4.解析 data--->字符串
     //NSUTF8StringEncoding
     NSLog(@"%@",[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding]);

     NSLog(@"%zd",response.statusCode);
 }

 -(void)async
 {
     //1.确定请求路径
     NSURL *url = [NSURL URLWithString:@"http://120.25.226.186:32812/login?username=520it&pwd=520it&type=JSON"];

     //2.创建请求对象
     //请求头不需要设置(默认的请求头)
     NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url];

     //3.发送异步请求
     /*
      第一个参数:请求对象
      第二个参数:队列 决定代码块completionHandler的调用线程
      第三个参数:completionHandler 当请求完成(成功|失败)的时候回调
         response:响应头
         data:响应体
         connectionError:错误信息
      */
     [NSURLConnection sendAsynchronousRequest:request queue:[[NSOperationQueue alloc]init] completionHandler:^(NSURLResponse * _Nullable response, NSData * _Nullable data, NSError * _Nullable connectionError) {

         //4.解析数据
         NSLog(@"%@",[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding]);

         NSHTTPURLResponse *res = (NSHTTPURLResponse *)response;
         NSLog(@"%zd",res.statusCode);
         NSLog(@"%@",[NSThread currentThread]);
     }];
 }

 -(void)delegate
 {
     //1.确定请求路径
     NSURL *url = [NSURL URLWithString:@"http://120.25.226.186:32812/login?username=123&pwd=123&type=JSON"];

     //2.创建请求对象
     NSURLRequest *request = [NSURLRequest requestWithURL:url];

     //3.设置代理,发送请求
     //3.1
     //[NSURLConnection connectionWithRequest:request delegate:self];

     //3.2
     //[[NSURLConnection alloc]initWithRequest:request delegate:self];

     //3.3 设置代理,时候发送请求需要检查startImmediately的值
     //(startImmediately == YES 会发送 | startImmediately == NO 则需要调用start方法)
     NSURLConnection * connect = [[NSURLConnection alloc]initWithRequest:request delegate:self startImmediately:NO];

     //调用开始方法
     [connect start];

 //    [connect cancel];//取消
 }

 #pragma mark ----------------------
 #pragma mark NSURLConnectionDataDelegate
 //1.当接收到服务器响应的时候调用
 -(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
 {
     NSLog(@"%s",__func__);
 }

 //2.接收到服务器返回数据的时候调用,调用多次
 -(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
 {
      NSLog(@"%s",__func__);

     //拼接数据
     [self.resultData appendData:data];
 }
 //3.当请求失败的时候调用
 -(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
 {
      NSLog(@"%s",__func__);
 }

 //4.请求结束的时候调用
 -(void)connectionDidFinishLoading:(NSURLConnection *)connection
 {
      NSLog(@"%s",__func__);

     NSLog(@"%@",[[NSString alloc]initWithData:self.resultData encoding:NSUTF8StringEncoding]);
 }
 @end