[iOS 多线程 & 网络 - 2.7] - NSURLCache

 1 //
 2 //  ViewController.m
 3 //  NSURLCacheDemo
 4 //
 5 //  Created by hellovoidworld on 15/1/28.
 6 //  Copyright (c) 2015年 hellovoidworld. All rights reserved.
 7 //
 8 
 9 #import "ViewController.h"
10 
11 @interface ViewController ()
12 - (IBAction)downloadData;
13 
14 @end
15 
16 @implementation ViewController
17 
18 - (void)viewDidLoad {
19     [super viewDidLoad];
20     // Do any additional setup after loading the view, typically from a nib.
21 }
22 
23 - (void)didReceiveMemoryWarning {
24     [super didReceiveMemoryWarning];
25     // Dispose of any resources that can be recreated.
26 }
27 
28 - (IBAction)downloadData {
29     // 1.创建请求
30     NSURL *url = [NSURL URLWithString:@"http://192.168.0.21:8080/MyTestServer/video?type=json"];
31     NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
32 
33     // 2.设置缓存策略
34     request.cachePolicy = NSURLRequestReturnCacheDataElseLoad; // 有缓存就不请求
35    
36     // 获得全局缓存
37     NSURLCache *cache = [NSURLCache sharedURLCache];
38    
39     // 定期处理缓存
40 //    if (超过一定时期) {
41 //        [cache removeCachedResponseForRequest:request];
42 //    }
43    
44     // 获得某个request的response
45     NSCachedURLResponse *response = [cache cachedResponseForRequest:request];
46     if (response) {
47         NSLog(@"有缓存");
48     } else {
49         NSLog(@"没有缓存");
50     }
51    
52     // 3.发送请求
53     [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
54        
55         NSLog(@"%@", [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil]);
56     }];
57    
58 }
59 @end