JSON序列化为实体对象

1、JSON 文本，文件名 applications.json

 [
  {
  "display_name": "500px",
  "developer_name": "500px",
  "identifier": "471965292"
  },
  {
  "display_name": "Airbnb",
  "developer_name": "Airbnb, Inc.",
  "identifier": "401626263"
  },
  {
  "display_name": "AppStore",
  "developer_name": "Apple, Inc.",
  "identifier": ""
  },
  {
  "display_name": "Camera",
  "developer_name": "Apple, Inc.",
  "identifier": ""
  },
  {
  "display_name": "Dropbox",
  "developer_name": "Dropbox, Inc.",
  "identifier": "327630330"
  },
  {
  "display_name": "Facebook",
  "developer_name": "Facebook, Inc.",
  "identifier": "284882215"
  },
  {
  "display_name": "WWDC",
  "developer_name": "Apple, Inc.",
  "identifier": "640199958"
  },
]

2、新建 Entity 对象类

#import <Foundation/Foundation.h>

//JSON 文件中去掉了一些类型
typedef NS_ENUM(NSUInteger, ApplicationType) {
    ApplicationType500px,
    ApplicationTypeAirbnb,
    ApplicationTypeAppstore,
    ApplicationTypeCamera,
    ApplicationTypeDropbox,
    ApplicationTypeFacebook,
    ApplicationTypeFancy,
    ApplicationTypeFoursquare,
    ApplicationTypeiCloud,
    ApplicationTypeInstagram,
    ApplicationTypeiTunesConnect,
    ApplicationTypeKickstarter,
    ApplicationTypePath,
    ApplicationTypePinterest,
    ApplicationTypePhotos,
    ApplicationTypePodcasts,
    ApplicationTypeRemote,
    ApplicationTypeSafari,
    ApplicationTypeSkype,
    ApplicationTypeSlack,
    ApplicationTypeTumblr,
    ApplicationTypeTwitter,
    ApplicationTypeVideos,
    ApplicationTypeVesper,
    ApplicationTypeVine,
    ApplicationTypeWhatsapp,
    ApplicationTypeWWDC
};

@interface Application : NSObject
@property (nonatomic, strong) NSString *displayName;
@property (nonatomic, strong) NSString *developerName;
@property (nonatomic, strong) NSString *identifier;
@property (nonatomic, strong) NSString *iconName;
@property (nonatomic) ApplicationType type;

- (instancetype)initWithDictionary:(NSDictionary *)dict;

@end

#import "Application.h"

@implementation Application

- (instancetype)initWithDictionary:(NSDictionary *)dict
{
    if (!dict) {
        return nil;
    }
    
    self = [super init];
    if (self) {
        self.displayName = [dict objectForKey:@"display_name"];
        self.developerName = [dict objectForKey:@"developer_name"];
        self.identifier = [dict objectForKey:@"identifier"];
    }
    return self;
}

- (void)setDisplayName:(NSString *)displayName
{
    _displayName = displayName;
    
    self.iconName = [[[NSString stringWithFormat:@"icon_%@", self.displayName] lowercaseString] stringByReplacingOccurrencesOfString:@" " withString:@"_"];
    
    self.type = applicationTypeFromString(self.displayName);
}

ApplicationType applicationTypeFromString(NSString *string)
{
    //JSON 文件中去掉了一些类型
    NSArray *arr = @[
                     @"500px",
                     @"Airbnb",
                     @"AppStore",
                     @"Camera",
                     @"Dropbox",
                     @"Facebook",
                     @"Fancy",
                     @"Foursquare",
                     @"iCloud",
                     @"Instagram",
                     @"iTunes Connect",
                     @"Kickstarter",
                     @"Path",
                     @"Pinterest",
                     @"Photos",
                     @"Podcasts",
                     @"Remote",
                     @"Safari",
                     @"Skype",
                     @"Slack",
                     @"Tumblr",
                     @"Twitter",
                     @"Videos",
                     @"Vesper",
                     @"Vine",
                     @"WhatsApp",
                     @"WWDC"
                     ];
    return (ApplicationType)[arr indexOfObject:string];
}

@end

3、读取并序列化 JSON ，把读取的信息，封装到 Entity 对象中

#pragma mark - Serialization
//序列化数据
- (void)serializeApplications
{
    NSString *path = [[NSBundle mainBundle] pathForResource:@"applications" ofType:@"json"];
    NSData *data = [NSData dataWithContentsOfFile:path];
    NSArray *objects = [[NSJSONSerialization JSONObjectWithData:data options:kNilOptions|NSJSONWritingPrettyPrinted error:nil] mutableCopy];
    
    self.applications = [NSMutableArray new];
    
    for (NSDictionary *dictionary in objects) {
        Application *app = [[Application alloc] initWithDictionary:dictionary];
        [self.applications addObject:app];
    }
}

4、调用序列化方法

@interface MainViewController () 

//保存 JSON 数据的 数组
@property (nonatomic, strong) NSMutableArray *applications;

@end

@implementation MainViewController

- (void)awakeFromNib
{
    [super awakeFromNib];
    
    //序列化数据
    [self serializeApplications];
}