JSON处理

在进行JSON处理的时候，按照其数据结构的定义，对其对应的字典进行操作取值即可，

对于嵌套的结构，数组等，抽象出相应的方法，一层层的去处理（责任链模式）就可以，这样很清晰

以下是一个factory, 根据给定的对象生产出对应的JSON字符串

 

采用递归的方法访问一个对象，讲其内容写到一个字典中支持的成员变量类型：1，NSString *2，NSArray *3，由1，2，构成的自定义类+ (NSMutableDictionary *) getDicFromObject: (id) theObject{if ([theObjectisKindOfClass:[NSStringclass]]){return theObject;}NSMutableDictionary * tmpDic = [[[NSMutableDictionaryalloc] init] autorelease];if (theObject ==nil){return tmpDic;}//get all the property fields namesNSString *className =NSStringFromClass([theObject class]);    const char *cClassName = [className UTF8String];    id theClass = objc_getClass(cClassName);unsignedint outCount, i;    objc_property_t *properties = class_copyPropertyList(theClass, &outCount);    NSMutableArray *propertyNames = [[NSMutableArrayalloc] initWithCapacity:1];    for (i = 0; i < outCount; i++) {        objc_property_t property = properties[i];        NSString *propertyNameString = [[NSStringalloc] initWithCString:property_getName(property) encoding:NSUTF8StringEncoding];         [propertyNamesaddObject:propertyNameString];        [propertyNameStringrelease];       NSLog(@"%s %s\n",property_getName(property), property_getAttributes(property));    }for (NSString *keyin propertyNames)    {        SEL selector = NSSelectorFromString(key);        id value = [theObject performSelector:selector];        if (value == nil)        {            value = [NSNullnull];[tmpDicsetObject:value forKey:key];continue;        }       //[finalDict setObject:value forKey:key];if ([valueisKindOfClass:[NSStringclass]]){[tmpDicsetObject:value forKey:key];}elseif ([value isKindOfClass:[NSArrayclass]]){NSMutableArray * valueArray = [[[NSMutableArrayalloc] init]autorelease];NSArray * aArray = (NSArray *)value;for (int i =0; i < [aArray count]; i++){[valueArrayaddObject:[NetRequestManagergetDicFromObject:[aArray objectAtIndex:i]]];//[tmpDic setObject:[NetRequestManager getDicFromObject:[aArray objectAtIndex:i]]//  forKey:key];}[tmpDicsetObject:valueArray forKey:key];}else {[tmpDicsetObject:[NetRequestManagergetDicFromObject:value] forKey:key];}    }return tmpDic;}

 

"PageSize":2  ,使用NSNumber类型来处理

NSNumber * 

{"RstMode":"1","AddrBookVersion":"5154812","PageStartIndex":"3","PageSize":2}

2012-06-27 09:57:59.364 appTest[20741:10a03] primaryEmail T@"NSString",&,N,VprimaryEmail

2012-06-27 09:57:59.365 appTest[20741:10a03] primaryMobile T@"NSString",&,N,VprimaryMobile

2012-06-27 09:57:59.365 appTest[20741:10a03] name T@"NameObj",&,N,Vname

2012-06-27 09:57:59.366 appTest[20741:10a03] lastName T@"NSString",&,N,VlastName

2012-06-27 09:57:59.367 appTest[20741:10a03] middleName T@"NSString",&,N,VmiddleName

2012-06-27 09:57:59.367 appTest[20741:10a03] firstName T@"NSString",&,N,VfirstName

2012-06-27 09:57:59.368 appTest[20741:10a03] {"primaryEmail":"America","primaryMobile":null,"name":{"firstName":null,"middleName":null,"lastName":null}}

2012-06-27 09:57:59.369 appTest[20741:10a03] contactListIDs T@"NSMutableArray",&,N,VcontactListIDs

2012-06-27 09:57:59.369 appTest[20741:10a03] contactID T@"NSString",&,N,VcontactID

2012-06-27 09:57:59.370 appTest[20741:10a03] contactBaseInfo T@"ContactBaseInfoObj",&,N,VcontactBaseInfo

2012-06-27 09:57:59.370 appTest[20741:10a03] primaryEmail T@"NSString",&,N,VprimaryEmail

2012-06-27 09:57:59.371 appTest[20741:10a03] primaryMobile T@"NSString",&,N,VprimaryMobile

2012-06-27 09:57:59.371 appTest[20741:10a03] name T@"NameObj",&,N,Vname

2012-06-27 09:57:59.372 appTest[20741:10a03] lastName T@"NSString",&,N,VlastName

2012-06-27 09:57:59.372 appTest[20741:10a03] middleName T@"NSString",&,N,VmiddleName

2012-06-27 09:57:59.373 appTest[20741:10a03] firstName T@"NSString",&,N,VfirstName

2012-06-27 09:57:59.373 appTest[20741:10a03] {"contactID":"123456","contactBaseInfo":{"primaryEmail":"America","primaryMobile":null,"name":{"firstName":null,"middleName":null,"lastName":null}},"contactListIDs":[]}

2012-06-27 09:57:59.374 appTest[20741:10a03] test ={"RstMode":1,"AddrBookVersion":"test","PageStartIndex":3,"PageSize":2}

2012-06-27 09:57:59.375 appTest[20741:10a03] the class is [NSDecimalNumber]

2012-06-27 09:57:59.375 appTest[20741:10a03] the int value is 2

2012-06-27 09:57:59.375 appTest[20741:10a03] tv is NSNumber class

{"RstMode":"1","AddrBookVersion":"5154812","PageStartIndex":"3","PageSize":2} 

通过解析得到的dic中，PageSize是NSDecimalNumber  NSNumber类型的，处理的时候需要注意

2012-06-27 13:36:51.393 appTest[23182:10a03] {"primaryEmail":"America","primaryMobile":null,"name":{"firstName":null,"middleName":null,"lastName":null}}

(gdb)po aDic

{

    name =     {

        firstName = "<null>";

        lastName = "<null>";

        middleName = "<null>";

    };

    primaryEmail = America;

    primaryMobile = "<null>";

}

(gdb) n

(gdb)po tnull

<null>

(gdb)po [tnull class]

NSNull

可以使用[NSNull null]来处理空值