我想将RestKit用于Restful Webservice，以便在LAMP环境和iOS-App之间进行通信。 因此，我进行了第一次测试，以检查是否一切都像可用的教程和RestKit页面中描述的那样。
现在代码看起来像这样：
RKObjectManager* objectManager = [RKObjectManager managerWithBaseURLString:@"http://localhost/resttest"];
objectManager.client.requestQueue.showsNetworkActivityIndicatorWhenBusy = YES;
#ifdef RESTKIT_GENERATE_SEED_DB
NSString *seedDatabaseName = nil;
NSString *databaseName = RKDefaultSeedDatabaseFileName;
#else
NSString *seedDatabaseName = RKDefaultSeedDatabaseFileName;
NSString *databaseName = @"CoreData.sqlite";
#endif
objectManager.objectStore = [RKManagedObjectStore objectStoreWithStoreFilename:databaseName usingSeedDatabaseName:seedDatabaseName managedObjectModel:nil delegate:self];
// Map Person Object
RKManagedObjectMapping *personMapping = [RKManagedObjectMapping mappingForClass:[Person class] inManagedObjectStore:objectManager.objectStore];
//RKManagedObjectMapping *personMapping = [RKManagedObjectMapping mappingForEntityWithName:@"Person" inManagedObjectStore:[RKObjectManager sharedManager].objectStore];
[personMapping mapKeyPath:@"id" toAttribute:@"person_id"];
[personMapping mapKeyPath:@"firstname" toAttribute:@"person_firstname"];
[personMapping mapKeyPath:@"lastname" toAttribute:@"person_lastname"];
[personMapping mapKeyPath:@"gender" toAttribute:@"person_gender"];
personMapping.primaryKeyAttribute = @"id";
// Register our mappings with the provider;
[objectManager.mappingProvider setMapping:personMapping forKeyPath:@"/person"];
objectManager.acceptMIMEType = RKMIMETypeJSON;
#ifdef RESTKIT_GENERATE_SEED_DB
RKLogConfigureByName("RestKit/ObjectMapping", RKLogLevelInfo);
RKLogConfigureByName("RestKit/CoreData", RKLogLevelTrace);
#endif
[objectManager loadObjectsAtResourcePath:@"/person" delegate:self];
这就是我的托管对象的样子：
@interface Person : NSManagedObject
@property (nonatomic, retain) NSString * person_firstname;
@property (nonatomic, retain) NSString * person_lastname;
@property (nonatomic, retain) NSString * person_gender;
@property (nonatomic, retain) NSNumber * person_id;
@end
这是服务器端的虚拟代码，只返回一些json示例字符串：
<?php
header('Content-type: application/json');
if($_SERVER['REQUEST_METHOD'] == 'GET')
{
$json_string = '{ "persons": [
{ "id": "1",
"firstname": "hans",
"lastname": "maier",
"genre": "m"
},
{ "id": "2",
"firstname": "michael",
"lastname": "schmidt",
"genre": "w"
}]
}';
echo $json_string;
}
?>
获取返回的json-String的URI是http://localhost/resttest/person(/index.php）。
我的问题是：
当我没有为''：
定义资源路径时，我总是会收到此错误E restkit.network:RKObjectLoader.m:216映射期间遇到的错误：无法找到keyPath的对象映射：''
我不知道为什么会这样。我试过的其他例子都没有这个问题，但我不知道我做错了什么。
我很感激有关这个主题的任何帮助，因为现在我不知道我做错了什么。
谢谢！
编辑03.05.2012：
以下是我在日志中的内容：
2012-05-03 12:52:05.067 RESTKitCoreDataTest[5139:13807] D restkit.object_mapping:RKObjectMapper.m:320 Performing object mapping sourceObject: {
persons = (
{
firstname = hans;
gender = m;
id = 1;
lastname = maier;
},
{
firstname = michael;
gender = w;
id = 2;
lastname = schmidt;
}
);
}
and targetObject: (null)
2012-05-03 12:52:05.067 RESTKitCoreDataTest[5139:13807] T restkit.object_mapping:RKObjectMapper.m:278 Examining keyPath '' for mappable content...
2012-05-03 12:52:05.067 RESTKitCoreDataTest[5139:13807] D restkit.object_mapping:RKObjectMapper.m:264 Found mappable data at keyPath '': {
persons = (
{
firstname = hans;
gender = m;
id = 1;
lastname = maier;
},
{
firstname = michael;
gender = w;
id = 2;
lastname = schmidt;
}
);
}
2012-05-03 12:52:05.073 RESTKitCoreDataTest[5139:13807] D restkit.object_mapping:RKObjectMapper.m:210 Asked to map source object {
persons = (
{
firstname = hans;
gender = m;
id = 1;
lastname = maier;
},
{
firstname = michael;
gender = w;
id = 2;
lastname = schmidt;
}
);
} with mapping <RKManagedObjectMapping:0x811eb60 objectClass=Person keyPath mappings => (
"RKObjectKeyPathMapping: id => person_id",
"RKObjectKeyPathMapping: firstname => person_firstname",
"RKObjectKeyPathMapping: lastname => person_lastname",
"RKObjectKeyPathMapping: gender => person_gender"
)>
2012-05-03 12:52:05.074 RESTKitCoreDataTest[5139:13807] D restkit.object_mapping:RKObjectMappingOperation.m:617 Starting mapping operation...
2012-05-03 12:52:05.074 RESTKitCoreDataTest[5139:13807] T restkit.object_mapping:RKObjectMappingOperation.m:618 Performing mapping operation: RKObjectMappingOperation for 'Person' object. Mapping values from object {
persons = (
{
firstname = hans;
gender = m;
id = 1;
lastname = maier;
},
{
firstname = michael;
gender = w;
id = 2;
lastname = schmidt;
}
);
} to object <Person: 0x6e295d0> (entity: Person; id: 0x6e29610 <x-coredata:///Person/t99EFF6DC-EBDA-405C-8AFF-D082E4A8542F2> ; data: {
"person_firstname" = nil;
"person_gender" = nil;
"person_id" = 0;
"person_lastname" = nil;
}) with object mapping <RKManagedObjectMapping:0x811eb60 objectClass=Person keyPath mappings => (
"RKObjectKeyPathMapping: id => person_id",
"RKObjectKeyPathMapping: firstname => person_firstname",
"RKObjectKeyPathMapping: lastname => person_lastname",
"RKObjectKeyPathMapping: gender => person_gender"
)>
2012-05-03 12:52:05.074 RESTKitCoreDataTest[5139:13807] T restkit.object_mapping:RKObjectMappingOperation.m:388 Did not find mappable attribute value keyPath 'id'
2012-05-03 12:52:05.074 RESTKitCoreDataTest[5139:13807] T restkit.object_mapping:RKObjectMappingOperation.m:388 Did not find mappable attribute value keyPath 'firstname'
2012-05-03 12:52:05.075 RESTKitCoreDataTest[5139:13807] T restkit.object_mapping:RKObjectMappingOperation.m:388 Did not find mappable attribute value keyPath 'lastname'
2012-05-03 12:52:05.075 RESTKitCoreDataTest[5139:13807] T restkit.object_mapping:RKObjectMappingOperation.m:388 Did not find mappable attribute value keyPath 'gender'
2012-05-03 12:52:05.075 RESTKitCoreDataTest[5139:13807] D restkit.object_mapping:RKObjectMappingOperation.m:638 Mapping operation did not find any mappable content
2012-05-03 12:52:05.075 RESTKitCoreDataTest[5139:13807] T restkit.core_data:RKManagedObjectMappingOperation.m:98 relationshipsAndPrimaryKeyAttributes: {
}
2012-05-03 12:52:05.075 RESTKitCoreDataTest[5139:13807] D restkit.object_mapping:RKObjectMapper.m:351 The following operations are in the queue: (
)
2012-05-03 12:52:05.075 RESTKitCoreDataTest[5139:13807] D restkit.object_mapping:RKObjectMapper.m:366 Finished performing object mapping. Results: {
}
2012-05-03 12:52:05.080 RESTKitCoreDataTest[5139:fb03] Loaded persons: (
)
答案 0 :(得分：1)
可能性1：
您似乎将映射设置为错误的keypath。
尝试
// Register our mappings with the provider;
[objectManager.mappingProvider setMapping:personMapping forKeyPath:@"persons"];
并检查它是否有效。
可能性2：
在映射中指定JSON的根路径。
尝试
// Map Person Object
RKManagedObjectMapping *personMapping = [RKManagedObjectMapping mappingForClass:[Person class] inManagedObjectStore:objectManager.objectStore];
[personMapping mapKeyPath:@"id" toAttribute:@"person_id"];
[personMapping mapKeyPath:@"firstname" toAttribute:@"person_firstname"];
[personMapping mapKeyPath:@"lastname" toAttribute:@"person_lastname"];
[personMapping mapKeyPath:@"gender" toAttribute:@"person_gender"];
personMapping.rootKeyPath = @"persons";
personMapping.primaryKeyAttribute = @"id";
并检查它是否有效。