NSURLCache,iOS

1.在didFinishLaunchingWithOptions添加初始化缓存方法。

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    // Override point for customization after application launch.

    CustomURLCache *urlCache = [[CustomURLCache alloc] initWithMemoryCapacity:20 * 1024 * 1024

                                                                 diskCapacity:200 * 1024 * 1024

                                                                     diskPath:nil

                                                                    cacheTime:0];

    [CustomURLCache setSharedURLCache:urlCache];

2.处理缓存request和response的方法

- (NSString *)cacheFolder;

- (NSString *)cacheFilePath:(NSString *)file;

- (NSString *)cacheRequestFileName:(NSString *)requestUrl;

- (NSString *)cacheRequestOtherInfoFileName:(NSString *)requestUrl;

- (NSCachedURLResponse *)dataFromRequest:(NSURLRequest *)request;

- (void)deleteCacheFolder;

@end

@implementation CustomURLCache

@synthesize cacheTime = _cacheTime;

@synthesize diskPath = _diskPath;

@synthesize responseDictionary = _responseDictionary;

- (id)initWithMemoryCapacity:(NSUInteger)memoryCapacity diskCapacity:(NSUInteger)diskCapacity diskPath:(NSString *)path cacheTime:(NSInteger)cacheTime {

    if (self = [self initWithMemoryCapacity:memoryCapacity diskCapacity:diskCapacity diskPath:path]) {

        self.cacheTime = cacheTime;

        if (path)

            self.diskPath = path;

        else

            self.diskPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];

        self.responseDictionary = [NSMutableDictionary dictionaryWithCapacity:0];

    }

    return self;

}

- (NSCachedURLResponse *)cachedResponseForRequest:(NSURLRequest *)request {

    if ([request.HTTPMethod compare:@"GET"] != NSOrderedSame) {

        return [super cachedResponseForRequest:request];

    }

    return [self dataFromRequest:request];

}

- (void)removeAllCachedResponses {

    [super removeAllCachedResponses];

    [self deleteCacheFolder];

}

- (void)removeCachedResponseForRequest:(NSURLRequest *)request {

    [super removeCachedResponseForRequest:request];

    NSString *url = request.URL.absoluteString;

    NSString *fileName = [self cacheRequestFileName:url];

    NSString *otherInfoFileName = [self cacheRequestOtherInfoFileName:url];

    NSString *filePath = [self cacheFilePath:fileName];

    NSString *otherInfoPath = [self cacheFilePath:otherInfoFileName];

    NSFileManager *fileManager = [NSFileManager defaultManager];

    [fileManager removeItemAtPath:filePath error:nil];

    [fileManager removeItemAtPath:otherInfoPath error:nil];

}

#pragma mark - custom url cache

- (NSString *)cacheFolder {

    return @"URLCACHE";

}

- (void)deleteCacheFolder {

    NSString *path = [NSString stringWithFormat:@"%@/%@", self.diskPath, [self cacheFolder]];

    NSFileManager *fileManager = [NSFileManager defaultManager];

    [fileManager removeItemAtPath:path error:nil];

}

- (NSString *)cacheFilePath:(NSString *)file {

    NSString *path = [NSString stringWithFormat:@"%@/%@", self.diskPath, [self cacheFolder]];

    NSFileManager *fileManager = [NSFileManager defaultManager];

    BOOL isDir;

    if ([fileManager fileExistsAtPath:path isDirectory:&isDir] && isDir) {

    } else {

        [fileManager createDirectoryAtPath:path withIntermediateDirectories:YES attributes:nil error:nil];

    }

    return [NSString stringWithFormat:@"%@/%@", path, file];

}

- (NSString *)cacheRequestFileName:(NSString *)requestUrl {

    return [CacheUtil md5Hash:requestUrl];

}

- (NSString *)cacheRequestOtherInfoFileName:(NSString *)requestUrl {

    return [CacheUtil md5Hash:[NSString stringWithFormat:@"%@-otherInfo", requestUrl]];

}

- (NSCachedURLResponse *)dataFromRequest:(NSURLRequest *)request {

    NSString *url = request.URL.absoluteString;

    NSString *fileName = [self cacheRequestFileName:url];

    NSString *otherInfoFileName = [self cacheRequestOtherInfoFileName:url];

    NSString *filePath = [self cacheFilePath:fileName];

    NSString *otherInfoPath = [self cacheFilePath:otherInfoFileName];

    NSDate *date = [NSDate date];

    NSFileManager *fileManager = [NSFileManager defaultManager];

    if ([fileManager fileExistsAtPath:filePath]) {

        BOOL expire = false;

        NSDictionary *otherInfo = [NSDictionary dictionaryWithContentsOfFile:otherInfoPath];

        if (self.cacheTime > 0) {

            NSInteger createTime = [[otherInfo objectForKey:@"time"] intValue];

            if (createTime + self.cacheTime < [date timeIntervalSince1970]) {

                expire = true;

            }

        }

        if (expire == false) {

            if (![Reachability networkAvailable]) {

                NSLog(@"data from cache ...");

                NSData *data = [NSData dataWithContentsOfFile:filePath];

                NSURLResponse *response = [[NSURLResponse alloc] initWithURL:request.URL

                                                                    MIMEType:[otherInfo objectForKey:@"MIMEType"]

                                                       expectedContentLength:data.length

                                                            textEncodingName:[otherInfo objectForKey:@"textEncodingName"]];

                NSCachedURLResponse *cachedResponse = [[NSCachedURLResponse alloc] initWithResponse:response data:data] ;

                //            [response release];

                return cachedResponse;

            }

        } else {

            NSLog(@"cache expire ... ");

            [fileManager removeItemAtPath:filePath error:nil];

            [fileManager removeItemAtPath:otherInfoPath error:nil];

        }

    }

    if (![Reachability networkAvailable]) {

        return nil;

    }

    __block NSCachedURLResponse *cachedResponse = nil;

    //sendSynchronousRequest请求也要经过NSURLCache

    id boolExsite = [self.responseDictionary objectForKey:url];

    if (boolExsite == nil) {

        [self.responseDictionary setValue:[NSNumber numberWithBool:TRUE] forKey:url];

        [NSURLConnection sendAsynchronousRequest:request queue:[[NSOperationQueue alloc] init] completionHandler:^(NSURLResponse *response, NSData *data,NSError *error)

         {

             if (response && data) {

                 [self.responseDictionary removeObjectForKey:url];

                 if (error) {

                     NSLog(@"error : %@", error);

                     NSLog(@"not cached: %@", request.URL.absoluteString);

                     cachedResponse = nil;

                 }

                 if ([Reachability networkAvailable]) {

                     NSLog(@"cache url --- %@ ",url);

                     //save to cache

                     NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:[NSString stringWithFormat:@"%f", [date timeIntervalSince1970]], @"time",

                                           response.MIMEType, @"MIMEType",

                                           response.textEncodingName, @"textEncodingName", nil];

                     [dict writeToFile:otherInfoPath atomically:YES];

                     [data writeToFile:filePath atomically:YES];

                     cachedResponse = [[NSCachedURLResponse alloc] initWithResponse:response data:data];

                 }

             }

         }];

        return cachedResponse;

        //NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

    }

    return nil;

}