Mapper (Morphia 1.2.1-SNAPSHOT API)

java.lang.Object
- org.mongodb.morphia.mapping.Mapper

```
public class Mapper
extends Object
```
This is the heart of Morphia and takes care of mapping from/to POJOs/DBObjects

This class is thread-safe and keeps various "cached" data which should speed up processing.

Author:

Olafur Gauti Gudmundsson, Scott Hernandez

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`CLASS_NAME_FIELDNAME` Special field used by morphia to support various possibly loading issues; will be replaced when discriminators are implemented to support polymorphism
`static String`	`ID_KEY` The @`Id` field name that is stored with mongodb.
`static String`	`IGNORED_FIELDNAME` Special name that can never be used.

Constructor Summary

Constructors
Constructor and Description
`Mapper()` Creates a Mapper with default options
`Mapper(MapperOptions opts)` Creates a Mapper with the given options.
`Mapper(MapperOptions options, Mapper mapper)` Creates a new Mapper with the given options and a Mapper to copy.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addInterceptor(EntityInterceptor ei)` Adds an `EntityInterceptor`
`MappedClass`	`addMappedClass(Class c)` Creates a MappedClass and validates it.
`EntityCache`	`createEntityCache()` Creates a cache for tracking entities seen during processing
`<T> T`	`fromDb(Datastore datastore, DBObject dbObject, T entity, EntityCache cache)` Converts a DBObject back to a type-safe java object (POJO)
`<T> T`	`fromDBObject(Datastore datastore, Class<T> entityClass, DBObject dbObject, EntityCache cache)` Converts a DBObject back to a type-safe java object (POJO)
`Class<?>`	`getClassFromCollection(String collection)` Looks up the class mapped to a named collection.
`String`	`getCollectionName(Object object)` Gets the mapped collection for an object instance or Class reference.
`Converters`	`getConverters()`
`Object`	`getId(Object entity)` Gets the ID value for an entity
`Map<Class,Object>`	`getInstanceCache()`
`Collection<EntityInterceptor>`	`getInterceptors()` Gets list of `EntityInterceptor`s
`<T> Key<T>`	`getKey(T entity)` Gets the Key for an entity
`<T> Key<T>`	`getKey(T entity, String collection)` Gets the Key for an entity and a specific collection
`<T> List<Key<T>>`	`getKeysByManualRefs(Class<T> clazz, List<Object> refs)` Gets the Keys for a list of objects
`<T> List<Key<T>>`	`getKeysByRefs(List<DBRef> refs)` Gets the Keys for a list of objects
`MappedClass`	`getMappedClass(Object obj)` Gets the `MappedClass` for the object (type).
`Collection<MappedClass>`	`getMappedClasses()`
`Map<String,MappedClass>`	`getMCMap()`
`MapperOptions`	`getOptions()`
`protected LazyProxyFactory`	`getProxyFactory()`
`boolean`	`isMapped(Class c)` Checks to see if a Class has been mapped.
`DBRef`	`keyToDBRef(Key key)` Converts a Key to a DBRef
`<T> Key<T>`	`manualRefToKey(Class<T> type, Object id)` Creates a Key for a type and an ID value
`<T> Key<T>`	`refToKey(DBRef ref)` Converts a DBRef to a Key
`void`	`setOptions(MapperOptions options)` Sets the options this Mapper should use
`DBObject`	`toDBObject(Object entity)` /** Converts an entity (POJO) to a DBObject.
`DBObject`	`toDBObject(Object entity, Map<Object,DBObject> involvedObjects)` Converts an entity (POJO) to a DBObject.
`Object`	`toMongoObject(MappedField mf, MappedClass mc, Object value)` Converts a java object to a mongo-compatible object (possibly a DBObject for complex mappings).
`String`	`updateCollection(Key key)` Updates the collection value on a Key with the mapped value on the Key's type Class
`void`	`updateKeyAndVersionInfo(Datastore datastore, DBObject dbObj, EntityCache cache, Object entity)` Updates the @`Id` and @`Version` fields.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - ID_KEY
```
public static final String ID_KEY
```
    The @Id field name that is stored with mongodb.
    
    See Also:
    
    Constant Field Values
  - IGNORED_FIELDNAME
```
public static final String IGNORED_FIELDNAME
```
    Special name that can never be used. Used as default for some fields to indicate default state.
    
    See Also:
    
    Constant Field Values
  - CLASS_NAME_FIELDNAME
```
public static final String CLASS_NAME_FIELDNAME
```
    Special field used by morphia to support various possibly loading issues; will be replaced when discriminators are implemented to support polymorphism
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - Mapper
```
public Mapper(MapperOptions opts)
```
    Creates a Mapper with the given options.
    
    Parameters:
    
    opts - the options to use
  - Mapper
```
public Mapper()
```
    Creates a Mapper with default options
    
    See Also:
    
    MapperOptions
  - Mapper
```
public Mapper(MapperOptions options,
              Mapper mapper)
```
    Creates a new Mapper with the given options and a Mapper to copy. This is effectively a copy constructor that allows a developer to override the options.
    
    Parameters:
    
    options - the options to use
    
    mapper - the collection of MappedClasses to add
- Method Detail
  - addInterceptor
```
public void addInterceptor(EntityInterceptor ei)
```
    Adds an EntityInterceptor
    
    Parameters:
    
    ei - the interceptor to add
  - addMappedClass
```
public MappedClass addMappedClass(Class c)
```
    Creates a MappedClass and validates it.
    
    Parameters:
    
    c - the Class to map
    
    Returns:
    
    the MappedClass for the given Class
  - createEntityCache
```
public EntityCache createEntityCache()
```
    Creates a cache for tracking entities seen during processing
    
    Returns:
    
    the cache
  - fromDBObject
```
public <T> T fromDBObject(Datastore datastore,
                          Class<T> entityClass,
                          DBObject dbObject,
                          EntityCache cache)
```
    Converts a DBObject back to a type-safe java object (POJO)
    
    Type Parameters:
    
    T - the type of the entity
    
    Parameters:
    
    datastore - the Datastore to use when fetching this reference
    
    entityClass - The type to return, or use; can be overridden by the @see Mapper.CLASS_NAME_FIELDNAME in the DBObject
    
    dbObject - the DBObject containing the document from mongodb
    
    cache - the EntityCache to use
    
    Returns:
    
    the new entity
    
    See Also:
    
    CLASS_NAME_FIELDNAME
  - fromDb
```
public <T> T fromDb(Datastore datastore,
                    DBObject dbObject,
                    T entity,
                    EntityCache cache)
```
    Converts a DBObject back to a type-safe java object (POJO)
    
    Type Parameters:
    
    T - the type of the entity
    
    Parameters:
    
    datastore - the Datastore to use when fetching this reference
    
    dbObject - the DBObject containing the document from mongodb
    
    entity - the instance to populate
    
    cache - the EntityCache to use
    
    Returns:
    
    the entity
  - getClassFromCollection
```
public Class<?> getClassFromCollection(String collection)
```
    Looks up the class mapped to a named collection.
    
    Parameters:
    
    collection - the collection name
    
    Returns:
    
    the Class mapped to this collection name
  - getCollectionName
```
public String getCollectionName(Object object)
```
    Gets the mapped collection for an object instance or Class reference.
    
    Parameters:
    
    object - the object to process
    
    Returns:
    
    the collection name
  - getConverters
```
public Converters getConverters()
```
    Returns:
    
    the Converters bundle this Mapper uses
  - getId
```
public Object getId(Object entity)
```
    Gets the ID value for an entity
    
    Parameters:
    
    entity - the entity to process
    
    Returns:
    
    the ID value
  - getInstanceCache
```
public Map<Class,Object> getInstanceCache()
```
    Returns:
    
    the cache of instances
  - getInterceptors
```
public Collection<EntityInterceptor> getInterceptors()
```
    Gets list of EntityInterceptors
    
    Returns:
    
    the Interceptors
  - getKey
```
public <T> Key<T> getKey(T entity)
```
    Gets the Key for an entity
    
    Type Parameters:
    
    T - the type of the entity
    
    Parameters:
    
    entity - the entity to process
    
    Returns:
    
    the Key
  - getKey
```
public <T> Key<T> getKey(T entity,
                         String collection)
```
    Gets the Key for an entity and a specific collection
    
    Type Parameters:
    
    T - the type of the entity
    
    Parameters:
    
    entity - the entity to process
    
    collection - the collection to use in the Key rather than the mapped collection as defined on the entity's class
    
    Returns:
    
    the Key
  - getKeysByManualRefs
```
public <T> List<Key<T>> getKeysByManualRefs(Class<T> clazz,
                                            List<Object> refs)
```
    Gets the Keys for a list of objects
    
    Type Parameters:
    
    T - the type of the entity
    
    Parameters:
    
    clazz - the Class of the objects
    
    refs - the objects to fetch the keys for
    
    Returns:
    
    the list of Keys
  - getKeysByRefs
```
public <T> List<Key<T>> getKeysByRefs(List<DBRef> refs)
```
    Gets the Keys for a list of objects
    
    Type Parameters:
    
    T - the type of the objects
    
    Parameters:
    
    refs - the objects to process
    
    Returns:
    
    the list of Keys
  - getMCMap
```
public Map<String,MappedClass> getMCMap()
```
    Returns:
    
    map of MappedClasses by class name
  - getMappedClass
```
public MappedClass getMappedClass(Object obj)
```
    Gets the MappedClass for the object (type). If it isn't mapped, create a new class and cache it (without validating).
    
    Parameters:
    
    obj - the object to process
    
    Returns:
    
    the MappedClass for the object given
  - getMappedClasses
```
public Collection<MappedClass> getMappedClasses()
```
    Returns:
    
    collection of MappedClasses
  - getOptions
```
public MapperOptions getOptions()
```
    Returns:
    
    the options used by this Mapper
  - setOptions
```
public void setOptions(MapperOptions options)
```
    Sets the options this Mapper should use
    
    Parameters:
    
    options - the options to use
  - isMapped
```
public boolean isMapped(Class c)
```
    Checks to see if a Class has been mapped.
    
    Parameters:
    
    c - the Class to check
    
    Returns:
    
    true if the Class has been mapped
  - keyToDBRef
```
public DBRef keyToDBRef(Key key)
```
    Converts a Key to a DBRef
    
    Parameters:
    
    key - the Key to convert
    
    Returns:
    
    the DBRef
  - manualRefToKey
```
public <T> Key<T> manualRefToKey(Class<T> type,
                                 Object id)
```
    Creates a Key for a type and an ID value
    
    Type Parameters:
    
    T - the type of the entity
    
    Parameters:
    
    type - the Class of the entity
    
    id - the ID value
    
    Returns:
    
    the Key
  - refToKey
```
public <T> Key<T> refToKey(DBRef ref)
```
    Converts a DBRef to a Key
    
    Type Parameters:
    
    T - the type of the referenced entity
    
    Parameters:
    
    ref - the DBRef to convert
    
    Returns:
    
    the Key
  - toDBObject
```
public DBObject toDBObject(Object entity)
```
    /** Converts an entity (POJO) to a DBObject. A special field will be added to keep track of the class type.
    
    Parameters:
    
    entity - The POJO
    
    Returns:
    
    the DBObject
    
    See Also:
    
    CLASS_NAME_FIELDNAME
  - toDBObject
```
public DBObject toDBObject(Object entity,
                           Map<Object,DBObject> involvedObjects)
```
    Converts an entity (POJO) to a DBObject. A special field will be added to keep track of the class type.
    
    Parameters:
    
    entity - The POJO
    
    involvedObjects - A Map of (already converted) POJOs
    
    Returns:
    
    the DBObject
    
    See Also:
    
    CLASS_NAME_FIELDNAME
  - toMongoObject
```
public Object toMongoObject(MappedField mf,
                            MappedClass mc,
                            Object value)
```
    Converts a java object to a mongo-compatible object (possibly a DBObject for complex mappings). Very similar to toDBObject(java.lang.Object). Used (mainly) by query/update operations.
    
    Parameters:
    
    mf - the MappedField for this value
    
    mc - the MappedClass for this value
    
    value - the value to convert
    
    Returns:
    
    the MongoDB compatible object
  - updateCollection
```
public String updateCollection(Key key)
```
    Updates the collection value on a Key with the mapped value on the Key's type Class
    
    Parameters:
    
    key - the Key to update
    
    Returns:
    
    the collection name on the Key
  - updateKeyAndVersionInfo
```
public void updateKeyAndVersionInfo(Datastore datastore,
                                    DBObject dbObj,
                                    EntityCache cache,
                                    Object entity)
```
    Updates the @Id and @Version fields.
    
    Parameters:
    
    datastore - the Datastore to use when fetching this reference
    
    dbObj - Value to update with; null means skip
    
    cache - the EntityCache
    
    entity - The object to update
  - getProxyFactory
```
protected LazyProxyFactory getProxyFactory()
```

Class Mapper

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ID_KEY

IGNORED_FIELDNAME

CLASS_NAME_FIELDNAME

Constructor Detail

Mapper

Mapper

Mapper

Method Detail

addInterceptor

addMappedClass

createEntityCache

fromDBObject

fromDb

getClassFromCollection

getCollectionName

getConverters

getId

getInstanceCache

getInterceptors

getKey

getKey

getKeysByManualRefs

getKeysByRefs

getMCMap

getMappedClass

getMappedClasses

getOptions

setOptions

isMapped

keyToDBRef

manualRefToKey

refToKey

toDBObject

toDBObject

toMongoObject

updateCollection

updateKeyAndVersionInfo

getProxyFactory