通过大众点评平台开发来简单了解一下,oc的网络编程和数据解析(json)
首先我们需要到大大众点评开发者平台申请一个key。http://developer.dianping.com/app/tech/api这个网站有api文档。
本文没有使用第三方库,网络其请求使用NSURLConnection类,json数据解析使用NSJSONSerialization。这个例子是根据条件获取商户信息。
1.定义常量
class="brush:objc;collapse:true;;gutter:true;">#define kSearchResto @"v1/business/find_businesses" #define kDPDomain @"http://api.dianping.com/" #define kDPAppKey @"。。。" #define kDPAppSecret @"。。。" #define kWFRequestimeOutInterval 60.0 #define kHttpMethodGET @"GET" #define kHttpMethodPOST @"POST"
2.创建数据类,包含商户信息
// // WFBusiness.h // WFSearch // // Created by ForrestWoo on 14-9-5. // Copyright (c) 2014年 ForrestWoo. All rights reserved. // #import <Foundation/Foundation.h> #import "WFRootModel.h" @interface WFBusiness : WFRootModel @property (nonatomic, assign) int business_id; @property (nonatomic, strong) NSString *name; @property (nonatomic, strong) NSString *branch_name; @property (nonatomic, strong) NSString *address; @property (nonatomic, strong) NSString *telephone; @property (nonatomic, strong) NSString *city; //星级图片链接。 @property (nonatomic, strong) NSString *rating_img_url; @property (nonatomic, strong) NSString *rating_s_img_url; @property (nonatomic, strong) NSArray *regions; @property (nonatomic, strong) NSArray *categories; //经纬度信息 @property (nonatomic, assign) float latitude; @property (nonatomic, assign) float longitude; @property (nonatomic, assign) float avg_rating; @property (nonatomic, assign) float product_score; @property (nonatomic, assign) float decoration_score; @property (nonatomic, assign) float service_score; //评价 分五种。1:一般,2:尚可,3:好,4:很好,5:非常好 @property (nonatomic, assign) int product_grade; @property (nonatomic, assign) int decoration_grade; @property (nonatomic, assign) int service_grade; //人均消费。 @property (nonatomic, assign) int avg_price; //点评。 @property (nonatomic, assign) int review_count; @property (nonatomic, strong) NSArray *review_list_url; @property (nonatomic, assign) int distance; @property (nonatomic, strong) NSString *business_url; //图片 @property (nonatomic, strong) NSString *photo_url; @property (nonatomic, strong) NSString *s_photo_url; @property (nonatomic, assign) int photo_count; @property (nonatomic, strong) NSArray *photo_list_url; //优惠券。 @property (nonatomic, assign) int has_coupon; @property (nonatomic, assign) int coupon_id; @property (nonatomic, strong) NSString *coupon_description; @property (nonatomic, strong) NSString *coupon_url; //团购信息。 @property (nonatomic, assign) int has_deal; @property (nonatomic, assign) int deal_count; @property (nonatomic, strong) NSArray *deals; @property (nonatomic, strong) NSString *deals_id; @property (nonatomic, strong) NSString *deals_description; @property (nonatomic, strong) NSString *deals_url; @property (nonatomic, assign) int has_online_reservation; @property (nonatomic, strong) NSString *online_reservation_url; - (id)initWithJson:(NSDictionary *)jsonData; @end
这里的属性名字并不是随便定义的,而是根据服务器端返回的字段名称定义的,它与返回的名称是一致的,目的是方便以后通过反射对类的属性赋值,这样我们不需要一一赋值,详情请继续
3.WFRootModel
#import <Foundation/Foundation.h>
//根类,定义一些通用的属性和消息
@interface WFRootModel : NSObject
//获取类的属性名称,以通过反射对对象的属性赋值。
- (NSArray *)PropertyKeys;
@end
#import "WFRootModel.h"
#import <objc/runtime.h>
@implementation WFRootModel
- (NSArray *)PropertyKeys
{
    unsigned int outCount,i;
    objc_property_t *pp = class_copyPropertyList([self class], &outCount);
    NSMutableArray *keys = [[NSMutableArray alloc] initWithCapacity:0];
    for (i = 0; i < outCount; i++)
    {
        objc_property_t property = pp[i];
        NSString *propertyName = [[NSString alloc] initWithCString:property_getName(property) encoding:NSUTF8StringEncoding];
        [keys addObject:propertyName];
    }
    
    return keys;
}
@end
此类赋予了它的子类一个重要行为,它只包含一个消息[- (NSArray *)PropertyKeys],它的作用是子类能够获取自己包含的所有属性。反射中会使用这些属性。
4.创建请求url
大众点评请求使用SHA加密。
[1]SHA加密类SHA1,需要引入
CommonDigest.h
@interface SHA1 : NSObject
+ (NSString *)getSHAString:(NSData *)aStringbytes;
@end
#import <CommonCrypto/CommonDigest.h>
#import "SHA1.h"
@implementation SHA1
+ (NSString *)getSHAString:(NSData *)aStringbytes
{
    unsigned char digest[CC_SHA1_DIGEST_LENGTH];
    
    if (CC_SHA1([aStringbytes bytes], [aStringbytes length], digest))
    {
        NSMutableString *digestString = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH];
        for (int i = 0; i < CC_SHA1_DIGEST_LENGTH; i++)
        {
            unsigned char aChar = digest[i];
            [digestString appendFormat:@"%02x",aChar];
        }
        return digestString;
    }
    else
    {
        return nil;
    }
}
@end
由于我对加密了解很少,所以就不做介绍了,只给出一个方法,供大家参考。
[2]返回根url,因为根url会常用到,我们就将它封装起来,以便后用
- (NSString *)getRootURL
{
    return kDPDomain;
}
[3]返回合法的url
- (NSString *)serializeURL:(NSString *)aBaseURL params:(NSDictionary *)aParams
{
	NSURL* parsedURL = [NSURL URLWithString:[aBaseURL stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
	NSMutableDictionary *paramsDic = [NSMutableDictionary dictionaryWithDictionary:[self parseQueryString:[parsedURL query]]];
	if (aParams) {
		[paramsDic setValuesForKeysWithDictionary:aParams];
	}
	
	NSMutableString *signString = [NSMutableString stringWithString:kDPAppKey];
	NSMutableString *paramsString = [NSMutableString stringWithFormat:@"appkey=%@", kDPAppKey];
	NSArray *sortedKeys = [[paramsDic allKeys] sortedArrayUsingSelector: @selector(compare:)];
	for (NSString *key in sortedKeys) {
		[signString appendFormat:@"%@%@", key, [paramsDic objectForKey:key]];
		[paramsString  appendFormat:@"&%@=%@", key, [paramsDic objectForKey:key]];
	}
    NSString *str = kDPAppSecret;
	[signString appendString:str];
	NSData *stringBytes = [signString dataUsingEncoding: NSUTF8StringEncoding];
    NSString *digestString = [SHA1 getSHAString:stringBytes];
    if (digestString)
    {
        [paramsString appendFormat:@"&sign=%@", [digestString uppercaseString]];
        NSLog(@"...%@...", [NSString stringWithFormat:@"%@://%@%@?%@", [parsedURL scheme], [parsedURL host], [parsedURL path], [paramsString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]);
		return [NSString stringWithFormat:@"%@://%@%@?%@", [parsedURL scheme], [parsedURL host], [parsedURL path], [paramsString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
    }
    else
    {
        return nil;
    }
}
5.创建网络连接,发送请求
使用NSURLConnection来完成网络连接
- (void)createConnectionWithUrl:(NSString *)urlString params:(NSDictionary *)aParams delegate:(id<WFRequestDelegate>)aDelegate
{
    NSString *urlStr = [self serializeURL:[self generateFullURL:urlString] params:aParams];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:urlStr] cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:kWFRequestimeOutInterval];
    
    [request setHTTPMethod:kHttpMethodGET];
    NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES];
    self.delegate = aDelegate;
//    [[[self class] sharedInstance] setConnections:conn];
}
6.返回结果以及数据解析
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    _responseData = [[NSMutableData alloc] init];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    [_responseData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSError *error = nil;
    id result= [NSJSONSerialization JSONObjectWithData:_responseData options:NSJSONReadingAllowFragments error:&error];
    if (!result)
    {
        NSDictionary *userInfo = [NSDictionary dictionaryWithObjectsAndKeys:error,@"error", nil];
        NSError *err = [NSError errorWithDomain:@"domain is error" code:-1 userInfo:userInfo];
        if ([self.delegate respondsToSelector:@selector(request:didfailWithError:)])
        {
            [self.delegate request:self didfailWithError:err];
        }
    }
    else
    {
        NSString *status = 0;
        if ([result isKindOfClass:[NSDictionary class]])
        {
            status = [result objectForKey:@"status"];
        }
        
        if ([status isEqualToString:@"OK"])
        {
            if ([self.delegate respondsToSelector:@selector(request:didfinishloadingWithResult:)])
            {
                [self.delegate request:self didfinishloadingWithResult:result == nil ?
                                 _responseData : result];
            }
        }
        else
        {
            if ([status isEqualToString:@"ERROR"])
            {
                //TODO:错误处理代码。
            }
        }
    }
//    NSString *str = [[NSString alloc] initWithData:_responseData encoding:NSUTF8StringEncoding];
//    NSLog(@"_responseData:%@", str);
    
//    [self clearData];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    NSLog(@"ERROR!%@", error.description);
}
返回的数据存储在一个WFFindBusinessesResult的实例中。
//super class for result. @interface WFUrlResult : NSObject @property (nonatomic, strong) NSString *status; @property (nonatomic, assign) NSInteger total_count; @property (nonatomic, assign) NSInteger count; - (id)initWithJson:(NSDictionary *)jsonData; @end @interface WFFindBusinessesResult : WFUrlResult @property (nonatomic, strong) NSArray *businesses; @end
对对象赋值非常简单
@implementation WFFindBusinessesResult
- (id)initWithJson:(NSDictionary *)jsonData
{
    
    self.status = [jsonData objectForKey:@"status"];
    self.count = [[jsonData objectForKey:@"count"] integerValue];
    self.total_count = [[jsonData objectForKey:@"total_count"] integerValue];
    NSArray *arr = nil;
    NSMutableArray *businessArr = [[NSMutableArray alloc] initWithCapacity:0];
    
    if ([jsonData isKindOfClass:[NSDictionary class]])
    {
        arr = [jsonData objectForKey:@"businesses"];
    //赋值,通过反射赋值,根本不需要一一对字段赋值。
        for (id obj in arr)
        {
            WFBusiness *bus = [[WFBusiness alloc] init];
            NSArray *propertyList = [[[WFBusiness alloc] init] PropertyKeys];
            for (NSString *key in propertyList)
            {
                
                [bus setValue:[obj objectForKey:key] forKey:key];
            }
            [businessArr addObject:bus];
            NSLog(@"photo is %@", [bus categories]);
        }
        
    }
    NSLog(@"businessArr count is %lu", [businessArr count]);
    self.Businesses = businessArr;
    return self;
}
@end
完整的封装类WFHTTPRequest。它用于创建一个连接,并发送请求,管理整个应用出现的网络连接,创建一个单例,全局唯一。
// // WFRequest.h // WFSearch // // Created by ForrestWoo on 14-8-30. // Copyright (c) 2014年 ForrestWoo. All rights reserved. // #import <Foundation/Foundation.h> @class WFHTTPRequest; @protocol WFRequestDelegate <NSObject> @optional - (void)request:(WFHTTPRequest *)request didfinishloadingWithResult:(id)aResult; - (void)request:(WFHTTPRequest *)request didfailWithError:(NSError *)aError; @end @interface WFHTTPRequest : NSObject @property (nonatomic, unsafe_unretained) id<WFRequestDelegate> delegate; @property (nonatomic, strong) NSString *aUrl; @property (nonatomic, strong) NSDictionary *aParams; @property (nonatomic, strong) NSArray *connections; + (WFHTTPRequest *)sharedInstance; - (void)createConnectionWithUrl:(NSString *)urlString params:(NSDictionary *)aParams delegate:(id<WFRequestDelegate>)aDelegate; - (void) cancel; - (NSString *)getRootURL; //api - (void)findBusinessesWithParams:(NSDictionary *)aParams delegate:(id<WFRequestDelegate>)aDelegate; - (void)findCityWithDelegate:(id<WFRequestDelegate>)aDelegate; - (void)getCategoriesForBusinessesWithDelegate:(id<WFRequestDelegate>)aDelegate; @end
//
//  WFRequest.m
//  WFSearch
//
//  Created by ForrestWoo on 14-8-30.
//  Copyright (c) 2014年 ForrestWoo. All rights reserved.
//
#import "WFHTTPRequest.h"
#import "WFConstants.h"
#import "SHA1.h"
@interface WFHTTPRequest () <NSURLConnectionDataDelegate>
//- (void)appendUTF8Body:(NSMutableData *)aBody dataString:(NSString *)aDataString;
//- (NSDictionary *)parseQueryString:(NSString *)query;
////- (void)handleResponseData:(NSData *)data;
//- (NSString *)generateFullURL:(NSString *)url;
////- (void)addConnection;
//- (NSString *)serializeURL:(NSString *)aBaseURL params:(NSDictionary *)aParams;
@end
static WFHTTPRequest *sharedObj = nil;
@implementation WFHTTPRequest
{
    NSURLConnection *_connection;
    NSMutableData *_responseData;
}
- (NSString *)getRootURL
{
    return kDPDomain;
}
- (NSString *)generateFullURL:(NSString *)url
{
    NSMutableString *str = [[NSMutableString alloc] initWithCapacity:0];
    
    [str appendString:[self getRootURL]];
    [str appendString:url];
    return str;
}
+ (WFHTTPRequest *)sharedInstance
{
    static dispatch_once_t pred = 0;
    
    dispatch_once(&pred, ^{
        sharedObj = [[super allocWithZone:NULL] init];
    });
    return sharedObj;
}
+ (id)allocWithZone:(struct _NSZone *)zone
{
    return [self sharedInstance];
}
- (void)createConnectionWithUrl:(NSString *)urlString params:(NSDictionary *)aParams delegate:(id<WFRequestDelegate>)aDelegate
{
    NSString *urlStr = [self serializeURL:[self generateFullURL:urlString] params:aParams];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:urlStr] cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:kWFRequestimeOutInterval];
    
    [request setHTTPMethod:kHttpMethodGET];
    NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES];
    self.delegate = aDelegate;
//    [[[self class] sharedInstance] setConnections:conn];
}
- (void)findBusinessesWithParams:(NSDictionary *)aParams delegate:(id<WFRequestDelegate>)aDelegate
{
    [self createConnectionWithUrl:kSearchResto params:aParams delegate:aDelegate];
}
- (void)findCityWithDelegate:(id<WFRequestDelegate>)aDelegate
{
    [self createConnectionWithUrl:kSearchCity params:nil delegate:aDelegate];
}
- (void)getCategoriesForBusinessesWithDelegate:(id<WFRequestDelegate>)aDelegate
{
    [self createConnectionWithUrl:kCategoriesWithBusinesses params:nil delegate:aDelegate];
}
//- (void)appendUTF8Body:(NSMutableData *)aBody dataString:(NSString *)aDataString
//{
//    [aBody appendData:[aDataString dataUsingEncoding:NSUTF8StringEncoding]];
//}
- (NSDictionary *)parseQueryString:(NSString *)query
{
    NSMutableDictionary *paramDict = [[NSMutableDictionary alloc] initWithDictionary:0];
    
    NSArray *paramArr = [query componentsSeparatedByString:@"&"];
    for (NSString *param in paramArr)
    {
        NSArray * elements = [param componentsSeparatedByString:@"="];
        if ([elements count] <= 1)
        {
            return nil;
        }
        
        NSString *key = [[elements objectAtIndex:0] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
        NSString *value = [[elements objectAtIndex:1] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
        
        [paramDict setObject:value forKey:key];
    }
    
    return paramDict;
}
- (NSString *)serializeURL:(NSString *)aBaseURL params:(NSDictionary *)aParams
{
	NSURL* parsedURL = [NSURL URLWithString:[aBaseURL stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
	NSMutableDictionary *paramsDic = [NSMutableDictionary dictionaryWithDictionary:[self parseQueryString:[parsedURL query]]];
	if (aParams) {
		[paramsDic setValuesForKeysWithDictionary:aParams];
	}
	
	NSMutableString *signString = [NSMutableString stringWithString:kDPAppKey];
	NSMutableString *paramsString = [NSMutableString stringWithFormat:@"appkey=%@", kDPAppKey];
	NSArray *sortedKeys = [[paramsDic allKeys] sortedArrayUsingSelector: @selector(compare:)];
	for (NSString *key in sortedKeys) {
		[signString appendFormat:@"%@%@", key, [paramsDic objectForKey:key]];
		[paramsString  appendFormat:@"&%@=%@", key, [paramsDic objectForKey:key]];
	}
    NSString *str = kDPAppSecret;
	[signString appendString:str];
	NSData *stringBytes = [signString dataUsingEncoding: NSUTF8StringEncoding];
    NSString *digestString = [SHA1 getSHAString:stringBytes];
    if (digestString)
    {
        [paramsString appendFormat:@"&sign=%@", [digestString uppercaseString]];
        NSLog(@"...%@...", [NSString stringWithFormat:@"%@://%@%@?%@", [parsedURL scheme], [parsedURL host], [parsedURL path], [paramsString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]);
		return [NSString stringWithFormat:@"%@://%@%@?%@", [parsedURL scheme], [parsedURL host], [parsedURL path], [paramsString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
    }
    else
    {
        return nil;
    }
}
- (void) cancel
{
    [_connection cancel];
}
+ (NSString *)getParamValueFromURL:(NSString *)aURl paramName:(NSString *)aParamName
{
    return nil;
}
#pragma mark - NSURLConnection Delegate Methods
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    _responseData = [[NSMutableData alloc] init];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    [_responseData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSError *error = nil;
    id result= [NSJSONSerialization JSONObjectWithData:_responseData options:NSJSONReadingAllowFragments error:&error];
    if (!result)
    {
        NSDictionary *userInfo = [NSDictionary dictionaryWithObjectsAndKeys:error,@"error", nil];
        NSError *err = [NSError errorWithDomain:@"domain is error" code:-1 userInfo:userInfo];
        if ([self.delegate respondsToSelector:@selector(request:didfailWithError:)])
        {
            [self.delegate request:self didfailWithError:err];
        }
    }
    else
    {
        NSString *status = 0;
        if ([result isKindOfClass:[NSDictionary class]])
        {
            status = [result objectForKey:@"status"];
        }
        
        if ([status isEqualToString:@"OK"])
        {
            if ([self.delegate respondsToSelector:@selector(request:didfinishloadingWithResult:)])
            {
                [self.delegate request:self didfinishloadingWithResult:result == nil ?
                                 _responseData : result];
            }
        }
        else
        {
            if ([status isEqualToString:@"ERROR"])
            {
                //TODO:错误处理代码。
            }
        }
    }
//    NSString *str = [[NSString alloc] initWithData:_responseData encoding:NSUTF8StringEncoding];
//    NSLog(@"_responseData:%@", str);
    
//    [self clearData];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    NSLog(@"ERROR!%@", error.description);
}
- (void)clearData
{
    _responseData = nil;
    [_connection cancel];
    _connection = nil;
}
@end
代码下载。下节详细介绍数据解析和网络编程,反射(运行时)