文件上传的基础知识

////  HMViewController.m//  01-文件上传//#import "HMViewController.h"#define HMEncode(str) [str dataUsingEncoding:NSUTF8StringEncoding]@interface HMViewController ()@end@implementation HMViewController- (void)viewDidLoad{    [super viewDidLoad];// Do any additional setup after loading the view, typically from a nib.}- (void)upload:(NSString *)name filename:(NSString *)filename mimeType:(NSString *)mimeType data:(NSData *)data parmas:(NSDictionary *)params{    // 文件上传    NSURL *url = [NSURL URLWithString:@"http://localhost:8080/MJServer/upload"];    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];    request.HTTPMethod = @"POST";        // 设置请求体    NSMutableData *body = [NSMutableData data];        /***************文件参数***************/    // 参数开始的标志    [body appendData:HMEncode(@"--heima\r\n")];    // name : 指定参数名(必须跟服务器端保持一致)    // filename : 文件名    NSString *disposition = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"%@\"\r\n", name, filename];    [body appendData:HMEncode(disposition)];    NSString *type = [NSString stringWithFormat:@"Content-Type: %@\r\n", mimeType];    [body appendData:HMEncode(type)];        [body appendData:HMEncode(@"\r\n")];    [body appendData:data];    [body appendData:HMEncode(@"\r\n")];        /***************普通参数***************/    [params enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {        // 参数开始的标志        [body appendData:HMEncode(@"--heima\r\n")];        NSString *disposition = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n", key];        [body appendData:HMEncode(disposition)];        [body appendData:HMEncode(@"\r\n")];        [body appendData:HMEncode(obj)];        [body appendData:HMEncode(@"\r\n")];    }];        /***************参数结束***************/    // heima--\r\n    [body appendData:HMEncode(@"--heima--\r\n")];    request.HTTPBody = body;        // 设置请求头    // 请求体的长度    [request setValue:[NSString stringWithFormat:@"%zd", body.length] forHTTPHeaderField:@"Content-Length"];    // 声明这个POST请求是个文件上传    [request setValue:@"multipart/form-data; boundary=heima" forHTTPHeaderField:@"Content-Type"];        // 发送请求    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {        if (data) {            NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];            NSLog(@"%@", dict);        } else {            NSLog(@"上传失败");        }    }];}- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{    // Socket 实现断点上传        //apache-tomcat-6.0.41/conf/web.xml 查找 文件的 mimeType//    UIImage *image = [UIImage imageNamed:@"test"];//    NSData *filedata = UIImagePNGRepresentation(image);//    [self upload:@"file" filename:@"test.png" mimeType:@"image/png" data:filedata parmas:@{@"username" : @"123"}];        // 给本地文件发送一个请求    NSURL *fileurl = [[NSBundle mainBundle] URLForResource:@"itcast.txt" withExtension:nil];    NSURLRequest *request = [NSURLRequest requestWithURL:fileurl];    NSURLResponse *repsonse = nil;    NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&repsonse error:nil];        // 得到mimeType    NSLog(@"%@", repsonse.MIMEType);    [self upload:@"file" filename:@"itcast.txt" mimeType:repsonse.MIMEType data:data parmas:@{                                                                                              @"username" : @"999",                                                                                              @"type" : @"XML"}];}@end