来看一下文件的上传与下载，我们先用 php 写一个简单的文件上传服务器，看一下代码
$content = file_get_contents("php://input");
$imgName = time();
$file_dir='images/'.$imgName.".jpg";
if($fp = fopen($file_dir,'w')){
if(fwrite($fp,$content)){
fclose($fp);
echo "上传成功";
}
}
由于之前说过以前的 NSUrlConnection 将要被放弃了，所以我们演示只用 NSUrlSession，来看一下图片的上传
- (void)uploadImageTest{
NSURLSession *session = [NSURLSession sharedSession];
NSMutableURLRequest * request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://localhost/upload/index.php"]];
[request addValue:@"image/jpeg" forHTTPHeaderField:@"Content-Type"];
[request addValue:@"text/html" forHTTPHeaderField:@"Accept"];
[request setHTTPMethod:@"POST"];
[request setCachePolicy:NSURLRequestReloadIgnoringCacheData];
[request setTimeoutInterval:20];
NSData * imagedata = UIImageJPEGRepresentation([UIImage imageNamed:@"0.jpg"],1);
//当然这里我们也可以是你用 base64 编码一下。
NSURLSessionUploadTask * uploadtask = [session uploadTaskWithRequest:request fromData:imagedata completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
NSLog(@"%@",[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);
}];
[uploadtask resume];
}
再来看一下文件的下载，基本的下载 是把数据都保存在_buffer中,_buffer是运行时内存中的一个对象,如果需要下载的数据量很大,内存会不够用,所以只能用于小文件的下载，大文件下载:边下边存,每次从服务器请求一段数据之后,就写入到沙盒中
小文件的下载：
- (void)downloadSmallTest{
// 下面这个方法是同步的
NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://localhost/upload/images/1467621024.jpg"]];
[data writeToFile:[NSHomeDirectory() stringByAppendingPathComponent:@"Documents/c.jpg"] atomically:YES];
NSString *str = @"http://localhost/upload/images/1467621024.jpg";
// 如果请求地址中有中文 需要编码
//str = [str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionDownloadTask *downloadTask = [session downloadTaskWithURL:[NSURL URLWithString:str] completionHandler:^(NSURL * _Nullable location, NSURLResponse * _Nullable response, NSError * _Nullable error) {
[data writeToFile:[NSHomeDirectory() stringByAppendingPathComponent:@"Documents/d.jpg"] atomically:YES];
NSLog(@"%@",[NSHomeDirectory() stringByAppendingPathComponent:@"Documents/d.jpg"]);
}];
[downloadTask resume];
}
大文件的下载（这里简单的用到了断点续传）
- (NSURLSession *)session{
if (!_session) {
NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];
self.session = [NSURLSession sessionWithConfiguration:config delegate:self delegateQueue:nil];
}
return _session;
}
//开始按钮
- (IBAction)start:(UIButton *)sender {
if (self.resumeData) {
[self resume];
}else{
[self start1];
}
}
//暂停按钮
- (IBAction)stop:(id)sender {
[self pause];
}
- (void)start1{
//创建下载任务
NSString *str = @"http://localhost/upload/zookeeper.zip";
NSURL *url = [NSURL URLWithString:str];
self.task = [self.session downloadTaskWithURL:url];
//开始下载任务
[self.task resume];
}
- (void)pause{
//暂停下载任务
__weak typeof(self) vc = self;
[self.task cancelByProducingResumeData:^(NSData * _Nullable resumeData) {
vc.resumeData = resumeData;
vc.task = nil;
NSLog(@"%@",resumeData);
}];
}
- (void)resume{
//继续下载任务
if(!self.resumeData){
NSString *str = @"http://localhost/upload/zookeeper.zip";
NSURL *url = [NSURL URLWithString:str];
self.task = [self.session downloadTaskWithURL:url];
}else{
self.task=[_session downloadTaskWithResumeData:self.resumeData];
}
[self.task resume];
self.resumeData=nil;
}
#pragma mark delegate
- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didResumeAtOffset:(int64_t)fileOffset expectedTotalBytes:(int64_t)expectedTotalBytes{
}
- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location{
//拿到Doc路径
NSString *path=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES ) lastObject];
//存储文件夹及文件名
NSString *pathUrl = [path stringByAppendingPathComponent:downloadTask.response.suggestedFilename];
NSFileManager *manager = [NSFileManager defaultManager];
//移动文件
[manager moveItemAtPath:location.path toPath:pathUrl error:nil];
NSLog(@"%@",pathUrl);
}
- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite{
self.progress.progress = (double)totalBytesWritten/totalBytesExpectedToWrite;
NSLog(@"已下载%f",(double)totalBytesWritten/totalBytesExpectedToWrite);
}
//这个方法没有使用
- (NSString *)getFilePath{
NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
// 文件夹的路径
NSString *directoryPath = [NSString stringWithFormat:@"%@/Files",path];
// 判断文件夹是否存在,如果不存在就创建一个文件夹
if (![[NSFileManager defaultManager] fileExistsAtPath:directoryPath]){
[[NSFileManager defaultManager] createDirectoryAtPath:directoryPath withIntermediateDirectories:YES attributes:nil error:nil];
}
// 文件路径
NSString *filePath = [NSString stringWithFormat:@"%@/a.zip",directoryPath];
// 判断文件夹中的文件是否存在,如果不存在 也要创建一个空的文件
if (![[NSFileManager defaultManager] fileExistsAtPath:filePath]){
[[NSFileManager defaultManager] createFileAtPath:filePath contents:nil attributes:nil];
}
return filePath;
}