实现 UIWebView 的离线缓存 CustionURLCache 库

方波娃
2023-12-01
这是网上一个大神写的

使用方法:在AppDelelgate

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

    // Override point for customization after application launch.

    

    //2M(内存空间)和200M(磁盘空间)  cacheTime:过期时间置为0:表示没有过期时间

    CustomNSURLCache *urlCache = [[CustomNSURLCachealloc] initWithMemoryCapacity:2 *1024 * 1024

                                                                 diskCapacity:200 * 1024 * 1024

                                                                     diskPath:nil

                                                                    cacheTime:300];

    [CustomNSURLCache setSharedURLCache:urlCache];

    return YES;

}


ViewController

- (void)viewDidLoad {

    [superviewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.


    NSLog(@"-- %@",NSHomeDirectory());

    

    

    UIWebView *WebView = [[UIWebViewalloc]initWithFrame:self.view.frame];

    WebView.delegate = self;

    self.web = WebView;

    [self.webloadRequest:[NSURLRequestrequestWithURL:[NSURLURLWithString:@"http://www.iqiyi.com"]]];

    [self.viewaddSubview:_web];

}


- (void)didReceiveMemoryWarning {

    [superdidReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

    CustomNSURLCache *urlCache = (CustomNSURLCache *)[NSURLCachesharedURLCache];

    [urlCache removeAllCachedResponses];

}



CustomNSURLCache.h

#import <Foundation/Foundation.h>

#import "Util.h"


@interface CustomNSURLCache : NSURLCache


/**

 *  过期时间

 */

@property(nonatomic,assign) NSInteger cacheTime;


/**

 *  存储路径

 */

@property(nonatomic,retain) NSString *diskPath;

@property(nonatomic,retain) NSMutableDictionary *responseDictionary;


/**

 *

 *  @param memoryCapacity 内存空间

 *  @param diskCapacity   磁盘空间

 *  @param path           存储路径(默认:Library>>Caches>>URLCACHE

 *  @param cacheTime      过期时间

 */

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


@end


CustomNSURLCache.m

#import "CustomNSURLCache.h"

#import "Reachability.h"


@interface CustomNSURLCache(private)


- (NSString *)cacheFolder;

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

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

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

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

- (void)deleteCacheFolder;


@end


@implementation CustomNSURLCache


@synthesize cacheTime = _cacheTime;

@synthesize diskPath = _diskPath;

@synthesize responseDictionary = _responseDictionary;


/**

 *

 *  @param memoryCapacity 内存空间

 *  @param diskCapacity   磁盘空间

 *  @param path           存储路径(默认:Library>>Caches>>URLCACHE

 *  @param cacheTime      过期时间

 */

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

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

        self.cacheTime = cacheTime;

        if (path)

            self.diskPath = path;

        else

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

        

        self.responseDictionary = [NSMutableDictionarydictionaryWithCapacity:0];

    }

    

    return self;

}


/**

 *  判断是否为GET请求或者 POST请求

 */

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

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

        return [supercachedResponseForRequest:request];

    }

    //    NSSet *supportSchemes = [[NSSet setWithObjects:@"http", @"https", @"ftp", nil] retain];

    //    NSURL *url = request.URL;

    //    if (![supportSchemes containsObject:url.scheme]) {

    //        [supportSchemes release];

    //        return [self dataFromRequest:request];

    //    }

    

    return [selfdataFromRequest:request];

}


- (void)removeAllCachedResponses {

    [superremoveAllCachedResponses];

    

    [selfdeleteCacheFolder];

}


/**

 *  重写系统的方法,移除本地存储的过期文件

 *  @param request 请求

 */

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

    [superremoveCachedResponseForRequest:request];

    

    NSString *url = request.URL.absoluteString;

    NSString *fileName = [selfcacheRequestFileName:url];

    NSString *otherInfoFileName = [selfcacheRequestOtherInfoFileName:url];

    NSString *filePath = [selfcacheFilePath:fileName];

    NSString *otherInfoPath = [selfcacheFilePath:otherInfoFileName];

    NSFileManager *fileManager = [NSFileManagerdefaultManager];

    [fileManager removeItemAtPath:filePath error:nil];

    [fileManager removeItemAtPath:otherInfoPatherror:nil];

}


#pragma mark - custom url cache

/**

 *  文件夹名字

 *

 *  @return URLCACHE

 */

- (NSString *)cacheFolder {

    return@"URLCACHE";

}


/**

 *  删除文件夹

 */

- (void)deleteCacheFolder {

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

    NSFileManager *fileManager = [NSFileManagerdefaultManager];

    [fileManager removeItemAtPath:path error:nil];

}


/**

 *  @param file 文件名字

 *

 *  @return 文件路径

 */

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

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

    NSFileManager *fileManager = [NSFileManagerdefaultManager];

    BOOL isDir;

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

        

    } else {

        [fileManager createDirectoryAtPath:pathwithIntermediateDirectories:YESattributes:nilerror:nil];

    }

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

}


/**

 *  将请求地址进行MD5加密

 *

 *  @param requestUrl 请求地址

 *

 *  @return 返回一个字符串

 */

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

    return [Utilmd5Hash:requestUrl];

}


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

    return [Utilmd5Hash:[NSStringstringWithFormat:@"%@-otherInfo", requestUrl]];

}


/**

 *  有请求时都会调用此方法,在此方法中进行保存request信息NSURLRequest为只读的

 *

 *  @param request 请求的 NSURLRequest

 *

 *  @return

 */

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

    NSString *url = request.URL.absoluteString;

    NSString *fileName = [selfcacheRequestFileName:url];

    NSString *otherInfoFileName = [selfcacheRequestOtherInfoFileName:url];

    NSString *filePath = [selfcacheFilePath:fileName];

    NSString *otherInfoPath = [selfcacheFilePath:otherInfoFileName];

    NSDate *date = [NSDatedate];

    

    NSFileManager *fileManager = [NSFileManagerdefaultManager];

    if ([fileManager fileExistsAtPath:filePath]) {

        BOOL expire = false;

        NSDictionary *otherInfo = [NSDictionarydictionaryWithContentsOfFile:otherInfoPath];

        

        if (self.cacheTime >0) {

            NSInteger createTime = [[otherInfoobjectForKey:@"time"]intValue];

           //判断时间是否过期,是否需要重新加载资源

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

                expire = true;

            }

        }

        

        if (expire == false) {

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

            //获取本地文件

            NSData *data = [NSDatadataWithContentsOfFile:filePath];

            //初始化一个Response里边的data为磁盘中保存的data

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

                                                                MIMEType:[otherInfo objectForKey:@"MIMEType"]

                                                   expectedContentLength:data.length

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

            NSCachedURLResponse *cachedResponse = [[NSCachedURLResponsealloc] initWithResponse:responsedata:data];

            return cachedResponse;

        } else {

            //移除之前磁盘中缓存过期的文件

            [fileManager removeItemAtPath:filePatherror:nil];

            [fileManager removeItemAtPath:otherInfoPatherror:nil];

        }

    }

    

    //网络断开则返回

    if (![ReachabilitynetworkAvailable]) {

        return nil;

    }

    

    __block NSCachedURLResponse *cachedResponse =nil;

    

    //sendSynchronousRequest请求也要经过NSURLCache

    id boolExsite = [self.responseDictionaryobjectForKey:url];

    if (boolExsite == nil) {

        [self.responseDictionarysetValue:[NSNumbernumberWithBool:TRUE]forKey:url];

        

        //发送请求

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

         {

             //判断是否存在数据

             if (response && data) {

                 //删除内存中之前的数据,使用新的数据

                 [self.responseDictionaryremoveObjectForKey:url];

                 

                 if (error) {

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

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

                     cachedResponse = nil;

                 }

                 

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

                 

                 //save to cache  保存

                 NSDictionary *dict = [NSDictionarydictionaryWithObjectsAndKeys:[NSStringstringWithFormat:@"%f", [datetimeIntervalSince1970]], @"time",

                                       response.MIMEType,@"MIMEType",

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

                 //写入文件

                 [dict writeToFile:otherInfoPathatomically:YES];

                 [data writeToFile:filePath atomically:YES];

                 

                 /**

                  把更改过后的 response

                  映射关系:

                  NSURLRequest --------> NSCachedURLResponse

                  */

                 cachedResponse = [[NSCachedURLResponsealloc] initWithResponse:responsedata:data];

             }

         }];

        return cachedResponse;

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

    }

    return nil;

}




@end







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