轉至http://blog.csdn.net/enuola/article/details/7903632
作為一種輕量級的數據交換格式,json正在逐步取代xml,成為網絡數據的通用格式。
有的json代碼格式比較混亂,可以使用此“http://www.bejson.com/”網站來進行JSON格式化校驗(點擊打開鏈接)。此網站不僅可以檢測Json代碼中的錯誤,而且可以以視圖形式顯示json中的數據內容,很是方便。
從IOS5開始,APPLE提供了對json的原生支持(NSJSONSerialization),但是為了兼容以前的ios版本,可以使用第三方庫來解析Json。
本文將介紹TouchJson、 SBJson 、JSONKit 和 iOS5所支持的原生的json方法,解析國家氣象局API,TouchJson和SBJson需要下載他們的庫
TouchJson包下載:http://download.csdn.net/detail/enuola/4523169
SBJson 包下載: http://download.csdn.net/detail/enuola/4523177
JSONKit包下載:http://download.csdn.net/detail/enuola/4523160
下面的完整程序源碼包下載:http://download.csdn.net/detail/enuola/4523223
PS:
國家氣象局提供的天氣預報接口
接口地址有三個:
http://www.weather.com.cn/data/sk/101010100.html
http://www.weather.com.cn/data/cityinfo/101010100.html
http://m.weather.com.cn/data/101010100.html
第三接口信息較為詳細,提供的是6天的天氣,關于API所返回的信息請見開源免費天氣預報接口API以及全國所有地區代碼!!(國家氣象局提供),全國各城市對應這一個id號,根據改變id好我們就可以解析出來各個城市對應天氣;
下面介紹四種方法解析JSON:
首先建立一個新的工程,(注意不要選擇ARC機制)添加如下控件:
如上圖所示。下面展出程序代碼:
文件 ViewController.h 中:
[cpp] view plaincopyprint?
#import <UIKit/UIKit.h>? ? @interface ViewController : UIViewController? ? @property (retain, nonatomic) IBOutlet UITextView *txtView;? ? - (IBAction)btnPressTouchJson:(id)sender;? - (IBAction)btnPressSBJson:(id)sender;? - (IBAction)btnPressIOS5Json:(id)sender;? - (IBAction)btnPressJsonKit:(id)sender;? ? @end? #import <UIKit/UIKit.h>@interface ViewController : UIViewController@property (retain, nonatomic) IBOutlet UITextView *txtView;- (IBAction)btnPressTouchJson:(id)sender;
- (IBAction)btnPressSBJson:(id)sender;
- (IBAction)btnPressIOS5Json:(id)sender;
- (IBAction)btnPressJsonKit:(id)sender;@end
文件ViewController.m中主要代碼:
(1)使用TouchJSon解析方法:(需導入包:#import "TouchJson/JSON/CJSONDeserializer.h")
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[cpp] view plaincopyprint?
? - (IBAction)btnPressTouchJson:(id)sender {? ??? ? ??? NSURL *url = [NSURL URLWithString:@"http://m.weather.com.cn/data/101010100.html"];? ??? ? ??? NSError *error;? ??? NSString *jsonString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];? ??? NSLog(@"jsonString--->%@",jsonString);? ??? ? ??? NSDictionary *rootDic = [[CJSONDeserializer deserializer] deserialize:[jsonString dataUsingEncoding:NSUTF8StringEncoding] error:&error];? ??? ? ??? NSDictionary *weatherInfo = [rootDic objectForKey:@"weatherinfo"];? ??? NSLog(@"weatherInfo--->%@",weatherInfo);? ??? ? ??? txtView.text = [NSString stringWithFormat:@"今天是 %@? %@? %@? 的天氣狀況是:%@? %@ ",[weatherInfo objectForKey:@"date_y"],[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"], [weatherInfo objectForKey:@"weather1"], [weatherInfo objectForKey:@"temp1"]];? ????? }? //使用TouchJson來解析北京的天氣
- (IBAction)btnPressTouchJson:(id)sender {//獲取API接口NSURL *url = [NSURL URLWithString:@"http://m.weather.com.cn/data/101010100.html"];//定義一個NSError對象,用于捕獲錯誤信息NSError *error;NSString *jsonString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];NSLog(@"jsonString--->%@",jsonString);//將解析得到的內容存放字典中,編碼格式為UTF8,防止取值的時候發生亂碼NSDictionary *rootDic = [[CJSONDeserializer deserializer] deserialize:[jsonString dataUsingEncoding:NSUTF8StringEncoding] error:&error];//因為返回的Json文件有兩層,去第二層內容放到字典中去NSDictionary *weatherInfo = [rootDic objectForKey:@"weatherinfo"];NSLog(@"weatherInfo--->%@",weatherInfo);//取值打印txtView.text = [NSString stringWithFormat:@"今天是 %@ %@ %@ 的天氣狀況是:%@ %@ ",[weatherInfo objectForKey:@"date_y"],[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"], [weatherInfo objectForKey:@"weather1"], [weatherInfo objectForKey:@"temp1"]];}
(2)使用SBJson解析方法:(需導入包:#import "SBJson/SBJson.h")
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[cpp] view plaincopyprint?
? - (IBAction)btnPressSBJson:(id)sender {? ??? NSURL *url = [NSURL URLWithString:@"http://m.weather.com.cn/data/101180701.html"];? ??? NSError *error = nil;? ??? NSString *jsonString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];? ??? SBJsonParser *parser = [[SBJsonParser alloc] init];? ????? ??? NSDictionary *rootDic = [parser objectWithString:jsonString error:&error];? ??? NSDictionary *weatherInfo = [rootDic objectForKey:@"weatherinfo"];? ??? txtView.text = [NSString stringWithFormat:@"今天是 %@? %@? %@? 的天氣狀況是:%@? %@ ",[weatherInfo objectForKey:@"date_y"],[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"], [weatherInfo objectForKey:@"weather1"], [weatherInfo objectForKey:@"temp1"]];? }? //使用SBJson解析南陽的天氣
- (IBAction)btnPressSBJson:(id)sender {NSURL *url = [NSURL URLWithString:@"http://m.weather.com.cn/data/101180701.html"];NSError *error = nil;NSString *jsonString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];SBJsonParser *parser = [[SBJsonParser alloc] init];NSDictionary *rootDic = [parser objectWithString:jsonString error:&error];NSDictionary *weatherInfo = [rootDic objectForKey:@"weatherinfo"];txtView.text = [NSString stringWithFormat:@"今天是 %@ %@ %@ 的天氣狀況是:%@ %@ ",[weatherInfo objectForKey:@"date_y"],[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"], [weatherInfo objectForKey:@"weather1"], [weatherInfo objectForKey:@"temp1"]];
}
(3)使用IOS5自帶解析類NSJSONSerialization方法解析:(無需導入包,IOS5支持,低版本IOS不支持)
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[cpp] view plaincopyprint?
- (IBAction)btnPressIOS5Json:(id)sender {? ????? ??? NSError *error;? ??? ? ??? NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://m.weather.com.cn/data/101180601.html"]];? ??? ? ??? NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];? ??? ? ??? NSDictionary *weatherDic = [NSJSONSerialization JSONObjectWithData:response options:NSJSONReadingMutableLeaves error:&error];? ??? NSDictionary *weatherInfo = [weatherDic objectForKey:@"weatherinfo"];? ??? txtView.text = [NSString stringWithFormat:@"今天是 %@? %@? %@? 的天氣狀況是:%@? %@ ",[weatherInfo objectForKey:@"date_y"],[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"], [weatherInfo objectForKey:@"weather1"], [weatherInfo objectForKey:@"temp1"]];? ??? NSLog(@"weatherInfo字典里面的內容為--》%@", weatherDic );? }? - (IBAction)btnPressIOS5Json:(id)sender {NSError *error;//加載一個NSURL對象NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://m.weather.com.cn/data/101180601.html"]];//將請求的url數據放到NSData對象中NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];//IOS5自帶解析類NSJSONSerialization從response中解析出數據放到字典中NSDictionary *weatherDic = [NSJSONSerialization JSONObjectWithData:response options:NSJSONReadingMutableLeaves error:&error];NSDictionary *weatherInfo = [weatherDic objectForKey:@"weatherinfo"];txtView.text = [NSString stringWithFormat:@"今天是 %@ %@ %@ 的天氣狀況是:%@ %@ ",[weatherInfo objectForKey:@"date_y"],[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"], [weatherInfo objectForKey:@"weather1"], [weatherInfo objectForKey:@"temp1"]];NSLog(@"weatherInfo字典里面的內容為--》%@", weatherDic );
}
(4)使用JSONKit的解析方法:(需導入包:#import "JSONKit/JSONKit.h")
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[cpp] view plaincopyprint?
- (IBAction)btnPressJsonKit:(id)sender {? ????? ??? ? ??? NSString *json1 = @"{\"a\":123, \"b\":\"abc\"}";? ??? NSLog(@"json1:%@",json1);? ??? NSDictionary *data1 = [json1 objectFromJSONString];? ??? NSLog(@"json1.a:%@",[data1 objectForKey:@"a"]);? ??? NSLog(@"json1.b:%@",[data1 objectForKey:@"b"]);? ??? [json1 release];? ????? ??? ? ??? NSString *json2 = @"{\"a\":123, \"b\":\"abc\", \"c\":[456, \"hello\"], \"d\":{\"name\":\"張三\", \"age\":\"32\"}}";? ??? NSLog(@"json2:%@", json2);? ??? NSDictionary *data2 = [json2 objectFromJSONStringWithParseOptions:JKParseOptionLooseUnicode];? ??? NSLog(@"json2.c:%@", [data2 objectForKey:@"c"]);? ??? NSLog(@"json2.d:%@", [data2 objectForKey:@"d"]);? ??? [json2 release];? }? - (IBAction)btnPressJsonKit:(id)sender {//如果json是“單層”的,即value都是字符串、數字,可以使用objectFromJSONStringNSString *json1 = @"{\"a\":123, \"b\":\"abc\"}";NSLog(@"json1:%@",json1);NSDictionary *data1 = [json1 objectFromJSONString];NSLog(@"json1.a:%@",[data1 objectForKey:@"a"]);NSLog(@"json1.b:%@",[data1 objectForKey:@"b"]);[json1 release];//如果json有嵌套,即value里有array、object,如果再使用objectFromJSONString,程序可能會報錯(測試結果表明:使用由網絡或得到的php/json_encode生成的json時會報錯,但使用NSString定義的json字符串時,解析成功),最好使用objectFromJSONStringWithParseOptions:NSString *json2 = @"{\"a\":123, \"b\":\"abc\", \"c\":[456, \"hello\"], \"d\":{\"name\":\"張三\", \"age\":\"32\"}}";NSLog(@"json2:%@", json2);NSDictionary *data2 = [json2 objectFromJSONStringWithParseOptions:JKParseOptionLooseUnicode];NSLog(@"json2.c:%@", [data2 objectForKey:@"c"]);NSLog(@"json2.d:%@", [data2 objectForKey:@"d"]);[json2 release];
}
另外,由于iOS5新增了JSON解析的API,我們將其和其他五個開源的JSON解析庫進行了解析速度的測試,下面是測試的結果。
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我們選擇的測試對象包含下面的這幾個框架,其中NSJSONSerialization是iOS5系統新增的JSON解析的API,需要iOS5的環境,如果您在更低的版本進行測試,應該屏蔽相應的代碼調用。
- [SBJSON (json-framework)](http://code.google.com/p/json-framework/)
- [TouchJSON (from touchcode)](http://code.google.com/p/touchcode/)
- [YAJL (objective-C bindings)](http://github.com/gabriel/yajl-objc)
- [JSONKit](https://github.com/johnezang/JSONKit)
- [NextiveJson](https://github.com/nextive/NextiveJson)
-[NSJSONSerialization](http://developer.apple.com/library/ios/#documentation/Foundation/Reference/NSJSONSerialization_Class/Reference/Reference.html#//apple_ref/doc/uid/TP40010946)
我們選擇了四個包含json格式的數據的文件進行測試。每一個文件進行100的解析動作,對解析的時間進行比較。
.....
測試的結果顯示,系統的API的解析速度最快,我們在工程項目中選擇使用,也是應用較為廣泛的SBJSON的解析速度為倒數第二差,令我大跌眼鏡。
與系統API較為接近的應該是JSONKit。
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這里沒有對API的開放接口和使用方式進行比較,若單純基于以上解析速度的測試:
1:iOS5應該選擇系統的API進行
2:不能使用系統API的應該選擇JSONKit
轉載于:https://www.cnblogs.com/haibosoft/p/3740504.html
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