源码0604-06-掌握-大文件断点下载（断点下载）

//
//  ViewController.m
//  05-掌握-大文件下载
//
//  Created by xiaomage on 15/7/15.
//  Copyright (c) 2015年 小码哥. All rights reserved.
//

// 文件的存放路径（caches）
#define XMGMp4File [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"test.mp4"]

#import "ViewController.h"

@interface ViewController () <NSURLSessionDataDelegate>
/** 下载任务 */
@property (nonatomic, strong) NSURLSessionDataTask *task;
/** session */
@property (nonatomic, strong) NSURLSession *session;
/** 写文件的流对象 */
@property (nonatomic, strong) NSOutputStream *stream;
/** 文件的总长度 */
@property (nonatomic, assign) NSInteger contentLength;
@end

@implementation ViewController

- (NSURLSession *)session
{
    if (!_session) {
        _session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[[NSOperationQueue alloc] init]];
    }
    return _session;
}

- (NSOutputStream *)stream
{
    if (!_stream) {
        _stream = [NSOutputStream outputStreamToFileAtPath:XMGMp4File append:YES];
    }
    return _stream;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    NSLog(@"%@", XMGMp4File);
    
    [[NSFileManager defaultManager] removeItemAtPath:XMGMp4File error:nil];
}

/**
 * 开始下载
 */
- (IBAction)start:(id)sender {
    // 创建一个Data任务
    self.task = [self.session dataTaskWithURL:[NSURL URLWithString:@"http://120.25.226.186:32812/resources/videos/minion_01.mp4"]];
    
    // 启动任务
    [self.task resume];
}

/**
 * 暂停下载
 */
- (IBAction)pause:(id)sender {
    [self.task suspend];
}

/**
 * 继续下载
 */
- (IBAction)goOn:(id)sender {
    [self.task resume];
}

#pragma mark - <NSURLSessionDataDelegate>
/**
 * 1.接收到响应
 */
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSHTTPURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition))completionHandler
{
    // 打开流
    [self.stream open];
    
    // 获得文件的总长度
    self.contentLength = [response.allHeaderFields[@"Content-Length"] integerValue];
    
    // 接收这个请求，允许接收服务器的数据
    completionHandler(NSURLSessionResponseAllow);
}

/**
 * 2.接收到服务器返回的数据（这个方法可能会被调用N次）
 */
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data
{
    // 写入数据
    [self.stream write:data.bytes maxLength:data.length];
    
    // 目前的下载长度
    NSInteger downloadLength = [[[NSFileManager defaultManager] attributesOfItemAtPath:XMGMp4File error:nil][NSFileSize] integerValue];
    
    // 下载进度
    NSLog(@"%f", 1.0 * downloadLength / self.contentLength);
}

/**
 * 3.请求完毕（成功失败）
 */
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error
{
    // 关闭流
    [self.stream close];
    self.stream = nil;
}

@end

07-掌握-大文件断点下载（离线断点）

//  ViewController.m
 05-掌握-大文件下载

// 所需要下载的文件的URL
#define XMGFileURL @"http://120.25.226.186:32812/resources/videos/minion_01.mp4"

// 文件名（沙盒中的文件名）
#define XMGFilename XMGFileURL.md5String

// 文件的存放路径（caches）
#define XMGFileFullpath [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:XMGFilename]

// 存储文件总长度的文件路径（caches）
#define XMGTotalLengthFullpath [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"totalLength.xmg"]

// 文件的已下载长度
#define XMGDownloadLength [[[NSFileManager defaultManager] attributesOfItemAtPath:XMGFileFullpath error:nil][NSFileSize] integerValue]

#import "ViewController.h"
#import "NSString+Hash.h"
#import "UIImageView+WebCache.h"

@interface ViewController () <NSURLSessionDataDelegate>
/** 下载任务 */
@property (nonatomic, strong) NSURLSessionDataTask *task;
/** session */
@property (nonatomic, strong) NSURLSession *session;
/** 写文件的流对象 */
@property (nonatomic, strong) NSOutputStream *stream;
/** 文件的总长度 */
@property (nonatomic, assign) NSInteger totalLength;
@end

@implementation ViewController

- (NSURLSession *)session
{
    if (!_session) {
        _session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[[NSOperationQueue alloc] init]];
    }
    return _session;
}

- (NSOutputStream *)stream
{
    if (!_stream) {
        _stream = [NSOutputStream outputStreamToFileAtPath:XMGFileFullpath append:YES];
    }
    return _stream;
}

- (NSURLSessionDataTask *)task
{
    if (!_task) {
        NSInteger totalLength = [[NSDictionary dictionaryWithContentsOfFile:XMGTotalLengthFullpath][XMGFilename] integerValue];
        if (totalLength && XMGDownloadLength == totalLength) {
            NSLog(@"----文件已经下载过了");
            return nil;
        }
        
        // 创建请求
        NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://120.25.226.186:32812/resources/videos/minion_01.mp4"]];
        
        // 设置请求头
        // Range : bytes=xxx-xxx
        NSString *range = [NSString stringWithFormat:@"bytes=%zd-", XMGDownloadLength];
        [request setValue:range forHTTPHeaderField:@"Range"];
        
        // 创建一个Data任务
        _task = [self.session dataTaskWithRequest:request];
    }
    return _task;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    NSLog(@"%@", XMGFileFullpath);
}

/**
 * 开始下载
 */
- (IBAction)start:(id)sender {
    // 启动任务
    [self.task resume];
}

/**
 * 暂停下载
 */
- (IBAction)pause:(id)sender {
    [self.task suspend];
}

#pragma mark - <NSURLSessionDataDelegate>
/**
 * 1.接收到响应
 */
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSHTTPURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition))completionHandler
{
    // 打开流
    [self.stream open];
    
    // 获得服务器这次请求 返回数据的总长度
    self.totalLength = [response.allHeaderFields[@"Content-Length"] integerValue] + XMGDownloadLength;
    
    // 存储总长度
    NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithContentsOfFile:XMGTotalLengthFullpath];
    if (dict == nil) dict = [NSMutableDictionary dictionary];
    dict[XMGFilename] = @(self.totalLength);
    [dict writeToFile:XMGTotalLengthFullpath atomically:YES];
    
    // 接收这个请求，允许接收服务器的数据
    completionHandler(NSURLSessionResponseAllow);
}

/**
 * 2.接收到服务器返回的数据（这个方法可能会被调用N次）
 */
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data
{
    // 写入数据
    [self.stream write:data.bytes maxLength:data.length];
    
    // 下载进度
    NSLog(@"%f", 1.0 * XMGDownloadLength / self.totalLength);
}

/**
 * 3.请求完毕（成功失败）
 */
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error
{
    // 关闭流
    [self.stream close];
    self.stream = nil;
    
    // 清除任务
    self.task = nil;
}

@end

//  XMGDownloadManager.h
//  05-掌握-大文件下载
#import <Foundation/Foundation.h>

@interface XMGDownloadManager : NSObject
+ (instancetype)sharedInstance;

- (void)download:(NSString *)url;
@end

//  XMGDownloadManager.m
//  05-掌握-大文件下载
#import "XMGDownloadManager.h"

@implementation XMGDownloadManager

@end

08-掌握-大文件断点下载（）

//  ViewController.m
//  05-掌握-大文件下载
// 文件的存放路径（caches）
#define XMGMp4File [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"test.mp4"]

// 文件的已下载长度
#define XMGDownloadLength [[[NSFileManager defaultManager] attributesOfItemAtPath:XMGMp4File error:nil][NSFileSize] integerValue]

#import "ViewController.h"

@interface ViewController () <NSURLSessionDataDelegate>
/** 下载任务 */
@property (nonatomic, strong) NSURLSessionDataTask *task;
/** session */
@property (nonatomic, strong) NSURLSession *session;
/** 写文件的流对象 */
@property (nonatomic, strong) NSOutputStream *stream;
/** 文件的总长度 */
@property (nonatomic, assign) NSInteger totalLength;
@end

@implementation ViewController

- (NSURLSession *)session
{
    if (!_session) {
        _session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[[NSOperationQueue alloc] init]];
    }
    return _session;
}

- (NSOutputStream *)stream
{
    if (!_stream) {
        _stream = [NSOutputStream outputStreamToFileAtPath:XMGMp4File append:YES];
    }
    return _stream;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    NSLog(@"%@", XMGMp4File);
}

/**
 * 开始下载
 */
- (IBAction)start:(id)sender {
    // 创建请求
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://120.25.226.186:32812/resources/videos/minion_01.mp4"]];
    
    // 设置请求头
    // Range : bytes=xxx-xxx
    NSString *range = [NSString stringWithFormat:@"bytes=%zd-", XMGDownloadLength];
    [request setValue:range forHTTPHeaderField:@"Range"];
    
    // 创建一个Data任务
    self.task = [self.session dataTaskWithRequest:request];
    
    // 启动任务
    [self.task resume];
}

/**
 * 暂停下载
 */
- (IBAction)pause:(id)sender {
    [self.task suspend];
}

/**
 * 继续下载
 */
- (IBAction)goOn:(id)sender {
    [self.task resume];
}

#pragma mark - <NSURLSessionDataDelegate>
/**
 * 1.接收到响应
 */
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSHTTPURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition))completionHandler
{
    // 打开流
    [self.stream open];
    
    // 获得服务器这次请求 返回数据的总长度
    self.totalLength = [response.allHeaderFields[@"Content-Length"] integerValue] + XMGDownloadLength;
    
    // 接收这个请求，允许接收服务器的数据
    completionHandler(NSURLSessionResponseAllow);
}

/**
 * 2.接收到服务器返回的数据（这个方法可能会被调用N次）
 */
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data
{
    // 写入数据
    [self.stream write:data.bytes maxLength:data.length];
    
    // 下载进度
    NSLog(@"%f", 1.0 * XMGDownloadLength / self.totalLength);
}

/**
 * 3.请求完毕（成功失败）
 */
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error
{
    // 关闭流
    [self.stream close];
    self.stream = nil;
}

@end