NSURLConnection Download File

调用：

URLDownload *downloader;- (IBAction) download:(id)sender {[urlField resignFirstResponder];NSString *tmpPath = [NSHomeDirectory() stringByAppendingPathComponent:@"tmp"];NSURLRequest *req = [NSURLRequest requestWithURL:[NSURL URLWithString:[urlField text]]];downloader = [[URLDownload alloc] initWithRequest:req directory:tmpPath delegate:self];}/////////////////////////////////////////////////////////////////////////URLDownloadDelegate implements- (void)downloadDidFinish:(URLDownload *)download {LOG(download.filePath);[self releaseDownloader];}- (void)download:(URLDownload *)download didCancelBecauseOf:(NSException *)exception {UIAlertView *alert = [[[UIAlertView alloc] initWithTitle:@"" message:[exception reason] delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK",nil] autorelease];[alert show];[self releaseDownloader];}- (void)download:(URLDownload *)download didFailWithError:(NSError *)error {UIAlertView *alert = [[[UIAlertView alloc] initWithTitle:@"" message:[error localizedDescription] delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK",nil] autorelease];[alert show];[self releaseDownloader];}- (void)download:(URLDownload *)download didReceiveDataOfLength:(NSUInteger)length {}

 

URLDownload.h

#import <Foundation/Foundation.h>@class URLDownload;@protocol URLDownloadDeleagte- (void)downloadDidFinish:(URLDownload *)download;- (void)download:(URLDownload *)download didCancelBecauseOf:(NSException *)exception;- (void)download:(URLDownload *)download didFailWithError:(NSError *)error;@optional- (void)download:(URLDownload *)download didReceiveDataOfLength:(NSUInteger)length;- (void)download:(URLDownload *)download didReceiveResponse:(NSURLResponse *)response;@end@interface URLDownload : NSObject {id <URLDownloadDeleagte, NSObject> delegate;NSString *directoryPath;NSString *filePath;NSURLRequest *request;NSFileHandle *file;NSURLConnection *con;}@property(readonly) NSString *filePath;- (id)initWithRequest:(NSURLRequest *)req directory:(NSString *)dir delegate:(id<URLDownloadDeleagte, NSObject>)dg;- (void)dealloc;- (void)cancel;// NSURLConnection delegate- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response;- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error;- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data;- (void)connectionDidFinishLoading:(NSURLConnection *)connection;//- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge;//- (void)connection:(NSURLConnection *)connection didCancelAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge;//- (NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse;//- (NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)redirectResponse;@end

 

 URLDownload.m

#import "URLDownload.h"@implementation URLDownload@synthesize filePath;- (id)initWithRequest:(NSURLRequest *)req directory:(NSString *)dir delegate:(id<URLDownloadDeleagte, NSObject>)dg {if (self = [super init]) {request = [req retain];directoryPath = [dir retain];delegate = [dg retain];con = [[NSURLConnection alloc] initWithRequest:request delegate:self];}return self;}- (void)dealloc {[request release];[directoryPath release];[filePath release];[file release];[delegate release];[con release];[super dealloc];}- (void)cancel {[con cancel];}// NSURLConnection delegate- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {filePath = [[response suggestedFilename] retain];if ([delegate respondsToSelector:@selector(download: didReceiveResponse:)])[delegate download:self didReceiveResponse:response];}- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {LOG([error localizedDescription]);if ([delegate respondsToSelector:@selector(download: didFailWithError:)])[delegate download:self didFailWithError:error];}- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {@try {if (file == nil) {NSFileManager *fm = [NSFileManager defaultManager];BOOL isDir;if (![fm fileExistsAtPath:directoryPath isDirectory:&isDir]) {NSError *error;if (![fm createDirectoryAtPath:directoryPath withIntermediateDirectories:YES attributes:nil error:&error]) {LOG([error localizedDescription]);LOG([error localizedFailureReason]);LOG([error localizedRecoverySuggestion]);[NSException raise:@"Exception" format:[error localizedDescription]];}} else if (!isDir) {[NSException raise:@"Exception" format:@"Failed to create directory at %@, because there is a file already.", directoryPath];}NSString *tmpFilePath = [[directoryPath stringByAppendingPathComponent:filePath] stringByStandardizingPath];int suffix = 0;while ([fm fileExistsAtPath:tmpFilePath]) {suffix++;tmpFilePath = [[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@%d", filePath, suffix]] stringByStandardizingPath];}[fm createFileAtPath:tmpFilePath contents:[NSData data] attributes:nil];[filePath release];filePath = [tmpFilePath retain];file = [[NSFileHandle fileHandleForWritingAtPath:filePath] retain];}[file writeData:data];if ([delegate respondsToSelector:@selector(download: didReceiveDataOfLength:)])[delegate download:self didReceiveDataOfLength:[data length]];}@catch (NSException * e) {LOG([e reason]);[connection cancel];[delegate download:self didCancelBecauseOf:e];}}- (void)connectionDidFinishLoading:(NSURLConnection *)connection {[delegate downloadDidFinish:self];}/* - (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge; - (void)connection:(NSURLConnection *)connection didCancelAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge; - (NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)redirectResponse; - (NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse;*/ @end