一步一步搭建自己的iOS网络请求库（一）

大家好，我是LastDay，很久没有写博客了，这周会分享一个的HTTP请求库的编写经验。

简单的介绍

介绍一下，NSURLSession是iOS7中新的网络接口，它与NSURLConnection是并列的。在程序在前台时，NSURLSession与NSURLConnection可以互为替代工作。两者在前台的时候其实没有什么区别，最主要的是程序在进入后台的时候，Background Session会更加灵活

测试NSURLSession

首先我们来新建一个工程，起名为LyHttp，在页面上放置一个按钮 ，起名为”测试”。

将按钮关联到我们的ViewController.m，起名为test。

添加以下代码

- (IBAction)test:(id)sender {

    NSURL *url = [NSURL URLWithString:@"http://cityuit.sinaapp.com/1.php"];

    NSURLSession *session = [NSURLSession sharedSession];

    NSURLRequest *request = [NSURLRequest requestWithURL:url];

    NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * data,NSURLResponse *reponse,NSError *error){

  NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

  NSLog(@"%@",string);

    }];

    [task resume];

}

http://cityuit.sinaapp.com/1.php是我自己写的一个接口用来测试的，会返回succeed。

我们来看一下触发效果：

测试完成

接下来我们来看看我们的NSURLSession是否为异步？OK，我们来简单的修改一下我们的程序吧。讲两个阻塞，来看看我们的主线程变化。

- (IBAction)test:(id)sender {

  NSURL *url = [NSURL URLWithString:@"http://cityuit.sinaapp.com/1.php"];

  NSURLSession *session = [NSURLSession sharedSession];

  NSURLRequest *request = [NSURLRequest requestWithURL:url];

  NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * data,NSURLResponse *reponse,NSError *error){

    //阻塞3秒

    [NSThread sleepForTimeInterval:3];

    NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

    NSLog(@"%@",string);

  }];

  [task resume];

}

可以看见效果就是连续点击3次，每隔三秒进行一次输出，直到三次执行完事，这就说明我们的主线程没有被阻塞，验证说明NSURLSession为异步。

曾将看过一篇文章中，介绍过，那篇文章里介绍NSURLSession 采用的是 “异步阻塞” 模型，即所有请求在发出后都进入 2# 线程执行，在 2# 线程内部按照阻塞队列模式执行。初步判断，此阻塞特性为 [NSURLSession sharedSession] 单例模式的结果。

一步一步搭建自己的iOS网络请求库（二）

大家好，我是LastDay，上一次分享了简单体验并且测试下一下NSURLSession。

我的博客地址：http://lastday.github.io

进行简单的封装

我们接下来将要加入动态的动态的HTTP参数（parameters）的功能，之后封装出我们自己的接口。

首先呢，我们先来对上一次的代码进行一次简单的封装，建立一个新的类LyNetWork，继承于NSObject类 。新建一个静态的request方法。将请求方式和URL传入

代码如下：

+(void)request :(NSString *)method URL:(NSString *)URL{

    NSURL *url = [NSURL URLWithString:URL];

    NSURLSession *session = [NSURLSession sharedSession];

    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

    request.HTTPMethod = method;

    NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * data,NSURLResponse *reponse,NSError *error){

        //NSdata转String

        NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

        NSLog(@"%@",string);

    }];

    [task resume];

}

OK

让我们在ViewController中进行一下测试，代码如下：

@IBAction func mainButtonBeTapped(sender: AnyObject) {

    [LyNetWork request:@"GET" URL:@"http://cityuit.sinaapp.com/1.php"];

}

接下来运行一下：OK 依然显示我们正确的测试结果：succeed

使用Block处理请求返回值

简单的介绍下闭包(block)，对于OC来说是一个新词，但不是新的概念，不是新的东西。学过Javascript的小伙伴对闭包应该不陌生吧~学过PHP的应该也不陌生，在PHP5.3版本以后也支持闭包, 也就是OC中所提到的Block。

现在对我们的request函数进行修改，LyNetWork.m代码如下：

+(void)requestMethod:(NSString *)method

                 URL:(NSString *)URL

             success:(void (^)(NSData *__nullable data,NSURLResponse * __nullable response))success

             failure:(void (^)(NSError *__nullable error))failure

{

    NSURL *url = [NSURL URLWithString:URL];

    NSURLSession *session = [NSURLSession sharedSession];

    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

    request.HTTPMethod = method;

    NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * data,NSURLResponse *response,NSError *error){

        if (error) {

            failure(error);

        }else{

            if (success) {

                success(data,response);

            }

        }

    }];

    [task resume];

}

接下来修改ViewController中的函数调用，代码修改后如下：

- (IBAction)test:(id)sender {

    [LyNetWork requestMethod:@"GET"

                         URL:@"http://cityuit.sinaapp.com/1.php"

                     success:^(NSData *data,NSURLResponse *response){

                         NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

                         NSLog(@"%@",string);

                     }

                     failure:^(NSError *error){

                         NSLog(@"%@",error);

                     }];

}

测试结果依然返回succeed，测试结果正确

接下来进行我们最难处理的地方，增加parameters处理能力

我们先来处理GET方法吧

GET 方法下，params 在经过 url encode 之后直接附在 URL 末尾发送给服务器

类似于这个样子 GET /foo.php?first_name=John&last_name=Doe&action=Submit HTTP/1.1

修改我们的requestMethod方法，将其进行一下更改，引入parameters参数

+(void)requestMethod:(nullable NSString *)method

                 URL:(nullable NSString *)URL

            parameters:(nullable id) parameters

             success:(nullable void (^)(NSData *__nullable data,NSURLResponse * __nullable response))success

             failure:(nullable void (^)(NSError *__nullable error))failure;

接下来就该处理我们的parameters参数了

我们从AFNetworking中借鉴一下他的处理方案（其实这里本人就是模仿编写罢了）

我们新建一个类起名为LYURLRequestSerialization，在LYURLRequestSerialization.h添加一下方法

+(NSString *)LYQueryStringFromParameters:(NSDictionary *)parameters;

进入我们的LYURLRequestSerialization.m文件中，添加以下代码：

#import "LYURLRequestSerialization.h"

@interface LYURLRequestSerialization()

@property (readwrite, nonatomic, strong) id  value;

@property (readwrite, nonatomic, strong) id  field;

@end

@implementation LYURLRequestSerialization

- (id)initWithField:(id)field value:(id)value {

    self = [super init];

    if (!self) {

        return nil;

    }

    self.field = field;

    self.value = value;

    return self;

}

#pragma mark -

FOUNDATION_EXPORT NSArray * LYQueryStringPairsFromDictionary(NSDictionary *dictionary);

FOUNDATION_EXPORT NSArray * LYQueryStringPairsFromKeyAndValue(NSString *key, id value);

+(NSString *)LYQueryStringFromParameters:(NSDictionary *)parameters {

    NSMutableArray *mutablePairs = [NSMutableArray array];

    for (LYURLRequestSerialization *pair in LYQueryStringPairsFromDictionary(parameters)) {

        [mutablePairs addObject:[pair URLEncodedStringValue]];

    }

    return [mutablePairs componentsJoinedByString:@"&"];

}

NSArray * LYQueryStringPairsFromDictionary(NSDictionary *dictionary) {

    return LYQueryStringPairsFromKeyAndValue(nil, dictionary);

}

NSArray * LYQueryStringPairsFromKeyAndValue(NSString *key, id value) {

    NSMutableArray *mutableQueryStringComponents = [NSMutableArray array];

    NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"description" ascending:YES selector:@selector(compare:)];

    if ([value isKindOfClass:[NSDictionary class]]) {

        NSDictionary *dictionary = value;

        for (id nestedKey in [dictionary.allKeys sortedArrayUsingDescriptors:@[ sortDescriptor ]]) {

            id nestedValue = dictionary[nestedKey];

            if (nestedValue) {

                [mutableQueryStringComponents addObjectsFromArray:LYQueryStringPairsFromKeyAndValue((key ? [NSString stringWithFormat:@"%@[%@]", key, nestedKey] : nestedKey), nestedValue)];

            }

        }

    } else if ([value isKindOfClass:[NSArray class]]) {

        NSArray *array = value;

        for (id nestedValue in array) {

            [mutableQueryStringComponents addObjectsFromArray:LYQueryStringPairsFromKeyAndValue([NSString stringWithFormat:@"%@[]", key], nestedValue)];

        }

    } else if ([value isKindOfClass:[NSSet class]]) {

        NSSet *set = value;

        for (id obj in [set sortedArrayUsingDescriptors:@[ sortDescriptor ]]) {

            [mutableQueryStringComponents addObjectsFromArray:LYQueryStringPairsFromKeyAndValue(key, obj)];

        }

    } else {

        [mutableQueryStringComponents addObject:[[LYURLRequestSerialization alloc] initWithField:key value:value]];

    }

    return mutableQueryStringComponents;

}

static NSString * LYPercentEscapedStringFromString(NSString *string) {

    static NSString * const kLYCharactersGeneralDelimitersToEncode = @":#[]@"; // does not include "?" or "/" due to RFC 3986 - Section 3.4

    static NSString * const kLYCharactersSubDelimitersToEncode = @"!$&'()*+,;=";

    NSMutableCharacterSet * allowedCharacterSet = [[NSCharacterSet URLQueryAllowedCharacterSet] mutableCopy];

    [allowedCharacterSet removeCharactersInString:[kLYCharactersGeneralDelimitersToEncode stringByAppendingString:kLYCharactersSubDelimitersToEncode]];

    static NSUInteger const batchSize = 50;

    NSUInteger index = 0;

    NSMutableString *escaped = @"".mutableCopy;

    while (index < string.length) {

#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Wgnu"

        NSUInteger length = MIN(string.length - index, batchSize);

#pragma GCC diagnostic pop

        NSRange range = NSMakeRange(index, length);

        range = [string rangeOfComposedCharacterSequencesForRange:range];

        NSString *substring = [string substringWithRange:range];

        NSString *encoded = [substring stringByAddingPercentEncodingWithAllowedCharacters:allowedCharacterSet];

        [escaped appendString:encoded];

        index += range.length;

    }

    return escaped;

}

- (NSString *)URLEncodedStringValue {

    if (!self.value || [self.value isEqual:[NSNull null]]) {

        return LYPercentEscapedStringFromString([self.field description]);

    } else {

        return [NSString stringWithFormat:@"%@=%@", LYPercentEscapedStringFromString([self.field description]), LYPercentEscapedStringFromString([self.value description])];

    }

}

@end

简单的说一下吧，以上的方法都是为了处理传入的NSDictonary参数，因为我们在使用的时候为了方便我们传入动态的parameters，所以他的的格式是这样的：

id parmenters = @{

                  @"value":@"LastDays",

                 };

将它处理后我们希望得到的样式应该是这样，对吧?

http:URL.php?value=LastDays

这个参数是一个动态的，我们不能确定里面到底有几组参数，而且还需要考虑的一个问题就是NSDictonary中嵌套NSDictonary的情况，我们处理这种问题的一个思想就是递归。从最里面开始处理。

OK，这样我们就实现了parameters处理能力

然后我们需要测试一下

为了进行测试我又重新更改了接口，提供了参数处理的能力，以下是新的接口：

http://cityuit.sinaapp.com/1.php  value=将要返回的值

更改下requestMethod方法

+(void)requestMethod:(NSString *)method

                 URL:(NSString *)URL

          parameters:(id) parameters

             success:(void (^)(NSData *__nullable data,NSURLResponse * __nullable response))success

             failure:(void (^)(NSError *__nullable error))failure

{

    NSString *newURL;

    if ([method isEqual:@"GET"]) {

        newURL = [[URL stringByAppendingString:@"?"] stringByAppendingString: [LYURLRequestSerialization LYQueryStringFromParameters:parameters]];

        NSLog(@"%@",newURL);

    }

    NSURL *url = [NSURL URLWithString:newURL];

    NSURLSession *session = [NSURLSession sharedSession];

    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

    request.HTTPMethod = method;

    NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * data,NSURLResponse *response,NSError *error){

        if (error) {

            failure(error);

        }else{

            if (success) {

                success(data,response);

            }

        }

    }];

    [task resume];

}

其中变化的地方：

if ([method isEqual:@"GET"]) {

        newURL = [[URL stringByAppendingString:@"?"] stringByAppendingString: [LYURLRequestSerialization LYQueryStringFromParameters:parameters]];

        NSLog(@"%@",newURL);

    }

以上代码的意思就是判断一下是否未GET请求，如果是的话将处理后的parameters加到尾部，以刚才的参数为例子，处理后的newURL为：http://cityuit.sinaapp.com/1.php?value=LastDays

也就是说返回值为LastDays

到ViewController.m中进行测试，测试代码如下：

- (IBAction)test:(id)sender {

    id parmenters = @{

                      @"value":@"LastDays",

                      };

    [LyNetWork requestMethod:@"GET"

                         URL:@"http://cityuit.sinaapp.com/1.php"

                  parameters:parmenters

                     success:^(NSData *data,NSURLResponse *response){

                         NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

                         NSLog(@"%@",string);

                     }

                     failure:^(NSError *error){

                         NSLog(@"%@",error);

                     }];

}

ok返回结果为LastDays，成功添加入动态的动态的HTTP参数（parameters）的功能。

一步一步搭建自己的iOS网络请求库（三）

大家好，我是LastDay，上一次分享了简单的封装，和GET请求。这次带给大家POST方法

我的博客地址：http://lastday.github.io

POST方法

POST 下很很多协议可提供我们选择，因为我们没有写文件的上传，所以我们就采用 application/x-www-form-urlencoded 这种简单的方式发送请求吧。requestMethod 中进行一些修改，增加POST方法。

代码如下：

+(void)requestMethod:(NSString *)method

                 URL:(NSString *)URL

          parameters:(id) parameters

             success:(void (^)(NSData *__nullable data,NSURLResponse * __nullable response))success

             failure:(void (^)(NSError *__nullable error))failure

{

    NSString *newURL;

    if ([method isEqual:@"GET"]) {

        newURL = [[URL stringByAppendingString:@"?"] stringByAppendingString: [LYURLRequestSerialization LYQueryStringFromParameters:parameters]];

        NSLog(@"%@",newURL);

    }else{

        newURL = URL;

    }

    NSURL *url = [NSURL URLWithString:newURL];

    NSURLSession *session = [NSURLSession sharedSession];

    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

    request.HTTPMethod = method;

    if([method isEqual:@"POST"]){

        [request addValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];

        request.HTTPBody =[[LYURLRequestSerialization LYQueryStringFromParameters:parameters] dataUsingEncoding:NSUTF8StringEncoding];

    }

    NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * data,NSURLResponse *response,NSError *error){

        if (error) {

            failure(error);

        }else{

            if (success) {

                success(data,response);

            }

        }

    }];

    [task resume];

}

接下来我们进行测试，原来的那个接口不支持POST请求，为了测试我就新写了一个借口，有两个参数为username和password，只有当两个参数都为1的时候返回ok，其余返回no

我们给出POST请求测试代码：

- (IBAction)test:(id)sender {

    NSString *URL = @"http://cityuit.sinaapp.com/p.php";

    id parmenters = @{

                      @"username":@"1",

                      @"password":@"1"

                      };

    [LyNetWork requestMethod:@"POST"

                         URL:URL

                  parameters:parmenters

                     success:^(NSData *data,NSURLResponse *response){

                         NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

                         NSLog(@"%@",string);

                     }

                     failure:^(NSError *error){

                         NSLog(@"%@",error);

                     }];

}

查看结果为：

若parmenters为1，222

id parmenters = @{

                      @"username":@"1",

                      @"password":@"222"

                      };

结果为：

一步一步搭建自己的iOS网络请求库（四）--解耦处理

1.确定 URL

2.确定 HTTP 方法（GET、POST 等）

3.添加特定的 HTTP 头

4.填充 HTTP Body

#import "LYHTTPRequestOperationManager.h"

#import "LYURLRequestSerialization.h"

@interface LYHTTPRequestOperationManager()

@property(nonatomic,strong) NSString *URL;

@property(nonatomic,strong) NSString *method;

@property(nonatomic,strong) NSDictionary *parameters;

@property(nonatomic,strong) NSMutableURLRequest *request;

@property(nonatomic,strong) NSURLSession *session;

@property(nonatomic,strong) NSURLSessionDataTask *task;

@end

@implementation LYHTTPRequestOperationManager

- (instancetype)initWithMethod:(NSString *)method URL:(NSString *)URL parameters:(id)parameters

{

    self = [super init];

    if (!self) {

        return nil;

    }

    self.URL = URL;

    self.method = method;

    self.parameters = parameters;

    self.request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:URL]];

    self.session = [NSURLSession sharedSession];

    return self;

}

@end

1.确定 URL

2.确定 HTTP 方法（GET、POST 等）

3.添加特定的 HTTP 头

4.填充 HTTP Body

-(void)setRequest{

    if ([self.method isEqual:@"GET"]&&self.parameters.count>0) {

        self.request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:[[self.URL stringByAppendingString:@"?"] stringByAppendingString: [LYURLRequestSerialization LYQueryStringFromParameters:self.parameters]]]];

    }

    self.request.HTTPMethod = self.method;

    if (self.parameters.count>0) {

        [self.request addValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];

    }

}

-(void)setBody{

    if (self.parameters.count>0&&![self.method isEqual:@"GET"]) {

        self.request.HTTPBody = [[LYURLRequestSerialization LYQueryStringFromParameters:self.parameters] dataUsingEncoding:NSUTF8StringEncoding];

    }

}

-(void)driveTask:(void(^)(NSData *__nullable data,NSURLResponse * __nullable response))success

         failure:(void (^)(NSError *__nullable error))failure

{

    [self setRequest];

    [self setBody];

    [self setTaskWithSuccess:success failure:failure];

}

+(void)requestWithMethod:(NSString *)method

                 URL:(NSString *)URL

             success:(void (^)(NSData *__nullable data,NSURLResponse * __nullable response))success

             failure:(void (^)(NSError *__nullable error))failure

{

    LYHTTPRequestOperationManager *manange = [[LYHTTPRequestOperationManager alloc] initWithMethod:method URL:URL parameters:nil];

    [manange driveTask:success failure:failure];

}

+(void)requestGetWithURL:(NSString *)URL

             success:(void (^)(NSData *__nullable data,NSURLResponse * __nullable response))success

             failure:(void (^)(NSError *__nullable error))failure

{

    LYHTTPRequestOperationManager *manange = [[LYHTTPRequestOperationManager alloc] initWithMethod:@"GET" URL:URL parameters:nil];

    [manange driveTask:success failure:failure];

}

//GET带parameters

+(void)requestGetWithURL:(NSString *)URL

          parameters:(id) parameters

             success:(void (^)(NSData *__nullable data,NSURLResponse * __nullable response))success

             failure:(void (^)(NSError *__nullable error))failure

{

    LYHTTPRequestOperationManager *manange = [[LYHTTPRequestOperationManager alloc] initWithMethod:@"GET" URL:URL parameters:parameters];

    [manange driveTask:success failure:failure];

}

+(void)requestPostWithURL:(NSString *)URL

                 success:(void (^)(NSData *__nullable data,NSURLResponse * __nullable response))success

                 failure:(void (^)(NSError *__nullable error))failure

{

    LYHTTPRequestOperationManager *manange = [[LYHTTPRequestOperationManager alloc] initWithMethod:@"POST" URL:URL parameters:nil];

    [manange driveTask:success failure:failure];

}

+(void)requestPostWithURL:(NSString *)URL

              parameters:(id) parameters

                 success:(void (^)(NSData *__nullable data,NSURLResponse * __nullable response))success

                 failure:(void (^)(NSError *__nullable error))failure

{

    LYHTTPRequestOperationManager *manange = [[LYHTTPRequestOperationManager alloc] initWithMethod:@"POST" URL:URL parameters:parameters];

    [manange driveTask:success failure:failure];

}

- (IBAction)test:(id)sender {

    NSString *postURL = @"http://cityuit.sinaapp.com/p.php";

    NSString *getURL= @"http://cityuit.sinaapp.com/1.php";

    id parmentersPost = @{

                      @"username":@"1",

                      @"password":@"1"

                      };

    id parmentersGet = @{

                      @"value":@"Lastday",

                          };

    [LyNetWork requestWithMethod:@"POST"

                             URL:@"http://cityuit.sinaapp.com/1.php?value=Lastday"

                         success:^(NSData *data,NSURLResponse *response){

                             NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

                             NSLog(@"requestWithMethod = %@",string);

                         }

                         failure:^(NSError *error){

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

                         }];

    [LyNetWork requestPostWithURL:postURL

                       parameters:parmentersPost

                          success:^(NSData *data,NSURLResponse *response){

                              NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

                              NSLog(@"requestPostWithURL(带参数) = %@",string);

                          }

                          failure:^(NSError *error){

                          }];

    [LyNetWork requestPostWithURL:postURL

                          success:^(NSData *data,NSURLResponse *response){

                              NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

                              NSLog(@"requestPostWithURL(不带参数) = %@",string);

                          }

                          failure:^(NSError *error){

                          }];

    [LyNetWork requestGetWithURL:getURL

                       parameters:parmentersGet

                          success:^(NSData *data,NSURLResponse *response){

                              NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

                              NSLog(@"requestGetWithURL(带参数) = %@",string);

                          }

                          failure:^(NSError *error){

                          }];

    [LyNetWork requestGetWithURL:getURL

                          success:^(NSData *data,NSURLResponse *response){

                              NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

                              NSLog(@"requestGetWithURL(不带参数) = %@",string);

                          }

                          failure:^(NSError *error){

                          }];

}