org.exolab.castor.mapping.loader

Class AbstractMappingLoader

java.lang.Object

org.exolab.castor.mapping.loader.AbstractMappingLoader2

org.exolab.castor.mapping.loader.AbstractMappingLoader

All Implemented Interfaces:

MappingLoader

Direct Known Subclasses:

JDOMappingLoader, MappingToolMappingLoader, XMLMappingLoader

public abstract class AbstractMappingLoader
extends AbstractMappingLoader2

Assists in the construction of descriptors. Can be used as a mapping resolver to the engine. Engines will implement their own mapping scheme typically by extending this class.

Version:

$Revision: 6385 $ $Date: 2006-04-10 16:39:24 -0600 (Mon, 10 Apr 2006) $

Author:

Assaf Arkin, Keith Visco

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	AbstractMappingLoader.TypeInfoReference A class used to by the createFieldHandler method in order to save the reference of the TypeInfo that was used.

Field Summary

Fields

Modifier and Type	Field and Description
protected static java.lang.Class[]	EMPTY_ARGS Empty array of class types used for reflection.
protected static ClassDescriptor	NO_DESCRIPTOR
protected static java.lang.Class[]	STRING_ARG The string argument for the valueOf method, used for introspection when searching for type-safe enumeration style classes.
protected static java.lang.String	VALUE_OF Factory method name for type-safe enumerations.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractMappingLoader(java.lang.ClassLoader loader) Constructs a new mapping helper.

Method Summary

Modifier and Type	Method and Description
protected ClassDescriptor	createDescriptor(ClassMapping clsMap) Creates a new descriptor.
protected FieldDescriptor	createFieldDesc(java.lang.Class javaClass, FieldMapping fieldMap) Creates a single field descriptor.
protected FieldHandler	createFieldHandler(java.lang.Class javaClass, java.lang.Class fldType, FieldMapping fldMap, AbstractMappingLoader.TypeInfoReference typeInfoRef) Creates the FieldHandler for the given FieldMapping.
protected static java.lang.reflect.Method	findAccessor(java.lang.Class javaClass, java.lang.String methodName, java.lang.Class fieldType, boolean getMethod) Returns the named accessor.
static java.lang.String[]	getIdentityColumnNames(java.lang.String[] ids, ClassMapping clsMap) Returns a list of column names that are part of the identity.
java.lang.String	getSourceType()
protected TypeInfo	getTypeInfo(java.lang.Class fieldType, CollectionHandler colHandler, FieldMapping fieldMap)
protected static boolean	isPrimitive(java.lang.Class type) Returns true if the given class should be treated as a primitive type
protected void	loadMappingInternal(MappingRoot mapping, java.lang.Object param) Loads the mapping from the specified mapping object.
protected void	resolveRelations(ClassDescriptor clsDesc)
protected java.lang.Class	resolveType(java.lang.String typeName) Returns the Java class for the named type.

Methods inherited from class org.exolab.castor.mapping.loader.AbstractMappingLoader2

addDescriptor, clear, descriptorIterator, getClassLoader, getDescriptor, isAllowRedefinition, loadMapping, setAllowRedefinitions, setClassLoader

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.exolab.castor.mapping.MappingLoader

getBindingType

Field Detail

EMPTY_ARGS

protected static final java.lang.Class[] EMPTY_ARGS

Empty array of class types used for reflection.

STRING_ARG

protected static final java.lang.Class[] STRING_ARG

The string argument for the valueOf method, used for introspection when searching for type-safe enumeration style classes.

VALUE_OF

protected static final java.lang.String VALUE_OF

Factory method name for type-safe enumerations.

See Also:

Constant Field Values

NO_DESCRIPTOR

protected static final ClassDescriptor NO_DESCRIPTOR

Constructor Detail

AbstractMappingLoader

protected AbstractMappingLoader(java.lang.ClassLoader loader)

Constructs a new mapping helper. This constructor is used by a derived class.

Parameters:

loader - The class loader to use, null for the default

Method Detail

getSourceType

public final java.lang.String getSourceType()

resolveType

protected final java.lang.Class resolveType(java.lang.String typeName)
                                     throws java.lang.ClassNotFoundException

Returns the Java class for the named type. The type name can be one of the accepted short names (e.g. integer) or the full Java class name (e.g. java.lang.Integer). If the short name is used, the primitive type might be returned.

Throws:

java.lang.ClassNotFoundException

loadMappingInternal

protected void loadMappingInternal(MappingRoot mapping,
                                   java.lang.Object param)
                            throws MappingException

Loads the mapping from the specified mapping object. Calls #createDescriptor to create each descriptor and AbstractMappingLoader2.addDescriptor(org.exolab.castor.mapping.ClassDescriptor) to store it. Also loads all the included mapping files.

Specified by:

loadMappingInternal in class AbstractMappingLoader2

Parameters:

mapping - The mapping information.

param - Arbitrary parameter that can be used by subclasses.

Throws:

MappingException - The mapping file is invalid.

resolveRelations

protected void resolveRelations(ClassDescriptor clsDesc)

createDescriptor

protected ClassDescriptor createDescriptor(ClassMapping clsMap)
                                    throws MappingException

Creates a new descriptor. The class mapping information is used to create a new stock ClassDescriptor. Implementations may extend this class to create a more suitable descriptor.

Parameters:

clsMap - The class mapping information.

Throws:

MappingException - An exception indicating why mapping for the class cannot be created.

createFieldDesc

protected FieldDescriptor createFieldDesc(java.lang.Class javaClass,
                                          FieldMapping fieldMap)
                                   throws MappingException

Creates a single field descriptor. The field mapping is used to create a new stock FieldDescriptor. Implementations may extend this class to create a more suitable descriptor.

Parameters:

javaClass - The class to which the field belongs.

fieldMap - The field mapping information.

Returns:

The field descriptor.

Throws:

MappingException - The field or its accessor methods are not found, not accessible, not of the specified type, etc.

createFieldHandler

protected final FieldHandler createFieldHandler(java.lang.Class javaClass,
                                                java.lang.Class fldType,
                                                FieldMapping fldMap,
                                                AbstractMappingLoader.TypeInfoReference typeInfoRef)
                                         throws MappingException

Creates the FieldHandler for the given FieldMapping.

Parameters:

javaClass - the class type of the parent of the field.

fldType - the Java class type for the field.

fldMap - the field mapping.

Returns:

the newly created FieldHandler.

Throws:

MappingException

getTypeInfo

protected TypeInfo getTypeInfo(java.lang.Class fieldType,
                               CollectionHandler colHandler,
                               FieldMapping fieldMap)
                        throws MappingException

Throws:

MappingException

findAccessor

protected static final java.lang.reflect.Method findAccessor(java.lang.Class javaClass,
                                                             java.lang.String methodName,
                                                             java.lang.Class fieldType,
                                                             boolean getMethod)
                                                      throws MappingException

Returns the named accessor. Uses reflection to return the named accessor and check the return value or parameter type, if specified.

Parameters:

javaClass - The class to which the field belongs.

methodName - The name of the accessor method.

fieldType - The type of the field if known, or null.

getMethod - True if get method, false if set method.

Returns:

The method, null if not found.

Throws:

MappingException - The method is not accessible or is not of the specified type.

getIdentityColumnNames

public static final java.lang.String[] getIdentityColumnNames(java.lang.String[] ids,
                                                              ClassMapping clsMap)

Returns a list of column names that are part of the identity.

Parameters:

ids - Known identity names.

clsMap - Class mapping.

Returns:

List of identity column names.

isPrimitive

protected static final boolean isPrimitive(java.lang.Class type)

Returns true if the given class should be treated as a primitive type

Returns:

true if the given class should be treated as a primitive type