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:

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:

$Revision$ $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 Class<?>[]	EMPTY_ARGS Empty array of class types used for reflection.
protected static String	NAME Method name to get string value of a type-safe enumerations.
protected static Class<?>[]	STRING_ARG The string argument for the valueOf method, used for introspection when searching for type-safe enumeration style classes.
protected static String	VALUE_OF Factory method name for type-safe enumerations.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
protected void	checkFieldNameDuplicates(FieldDescriptor[] fields, Class<?> cls) Checks all given fields for name equality and throws a MappingException if at least two fields have the same name.
protected abstract ClassDescriptor	createClassDescriptor(ClassMapping clsMap)
protected void	createClassDescriptors(MappingRoot mapping)
protected FieldDescriptorImpl	createFieldDesc(Class<?> javaClass, FieldMapping fieldMap) Creates a single field descriptor.
protected FieldDescriptorImpl[]	createFieldDescriptors(ClassMapping clsMap, Class<?> javaClass) Create field descriptors.
protected FieldHandler	createFieldHandler(Class<?> javaClass, Class<?> fldType, FieldMapping fldMap, AbstractMappingLoader.TypeInfoReference typeInfoRef) Creates the FieldHandler for the given FieldMapping.
protected void	createFieldHandlers(MappingRoot mapping) Load field handler definitions, check for duplicate definitions and instantiate the appropriate FieldHandler implementations.
protected FieldDescriptor[]	divideFieldDescriptors(FieldDescriptor[] fields, String[] ids, FieldDescriptor[] identities)
static Method	findAccessor(Class<?> javaClass, String methodName, Class<?> fieldType, boolean getMethod) Returns the named accessor.
protected ClassDescriptor	getDepended(ClassMapping clsMap, Class<?> javaClass) Gets the ClassDescriptor the given classMapping depends on.
protected ClassDescriptor	getExtended(ClassMapping clsMap, Class<?> javaClass) Gets the ClassDescriptor the given classMapping extends.
protected int	getIdColumnIndex(FieldDescriptor field, String[] ids) Finds the index in the given idColumnNames that has the same name as the given field.
static String[]	getIdentityColumnNames(String[] ids, ClassMapping clsMap) Returns a list of column names that are part of the identity.
InternalContext	getInternalContext()
protected ClassMapping	getOrigin(ClassMapping clsMap) Gets the top-most (i.e.
String	getSourceType()
protected TypeInfo	getTypeInfo(Class fieldType, CollectionHandler colHandler, FieldMapping fieldMap)
protected static boolean	isPrimitive(Class<?> type) Returns true if the given class should be treated as a primitive type
abstract void	loadMapping(MappingRoot mapping, Object param) Loads the mapping from the specified mapping object if not loaded previously.
protected abstract void	resolveRelations(ClassDescriptor clsDesc)
protected Class<?>	resolveType(String typeName) Returns the Java class for the named type.
void	setInternalContext(InternalContext internalContext)

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

addDescriptor, clear, getClassLoader, getDescriptor, getDescriptors, 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 Class<?>[] EMPTY_ARGS

Empty array of class types used for reflection.

STRING_ARG

protected static final 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 String VALUE_OF

Factory method name for type-safe enumerations.

See Also:

Constant Field Values

NAME

protected static final String NAME

Method name to get string value of a type-safe enumerations.

See Also:

Constant Field Values

Constructor Detail

AbstractMappingLoader

protected AbstractMappingLoader(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 String getSourceType()

loadMapping

public abstract void loadMapping(MappingRoot mapping,
                                 Object param)
                          throws MappingException

Loads the mapping from the specified mapping object if not loaded previously.

Parameters:

mapping - The mapping information.

param - Arbitrary parameter that can be used by subclasses.

Throws:

MappingException - The mapping file is invalid.

createFieldHandlers

protected void createFieldHandlers(MappingRoot mapping)
                            throws MappingException

Load field handler definitions, check for duplicate definitions and instantiate the appropriate FieldHandler implementations.

Parameters:

mapping - Mapping to load field handler definitions from.

Throws:

MappingException - If mapping contains more then one field handler definition with same name.

createClassDescriptors

protected final void createClassDescriptors(MappingRoot mapping)
                                     throws MappingException

Throws:

MappingException

createClassDescriptor

protected abstract ClassDescriptor createClassDescriptor(ClassMapping clsMap)
                                                  throws MappingException

Throws:

MappingException

getExtended

protected final ClassDescriptor getExtended(ClassMapping clsMap,
                                            Class<?> javaClass)
                                     throws MappingException

Gets the ClassDescriptor the given classMapping extends.

Parameters:

clsMap - The ClassMapping to find the required descriptor for.

javaClass - The name of the class that is checked (this is used for generating the exception).

Returns:

The ClassDescriptor the given ClassMapping extends or null if the given ClassMapping does not extend any.

Throws:

MappingException - If the given ClassMapping extends another ClassMapping but its descriptor could not be found.

getDepended

protected final ClassDescriptor getDepended(ClassMapping clsMap,
                                            Class<?> javaClass)
                                     throws MappingException

Gets the ClassDescriptor the given classMapping depends on.

Parameters:

clsMap - The ClassMapping to find the required ClassDescriptor for.

javaClass - The name of the class that is checked (this is used for generating the exception).

Returns:

The ClassDescriptor the given ClassMapping depends on or null if the given ClassMapping does not depend on any.

Throws:

MappingException - If the given ClassMapping depends on another ClassMapping but its descriptor could not be found.

checkFieldNameDuplicates

protected final void checkFieldNameDuplicates(FieldDescriptor[] fields,
                                              Class<?> cls)
                                       throws MappingException

Checks all given fields for name equality and throws a MappingException if at least two fields have the same name.

Parameters:

fields - The fields to be checked.

cls - Class that is checked (this is used for generating the exception).

Throws:

MappingException - If at least two fields have the same name.

resolveRelations

protected abstract void resolveRelations(ClassDescriptor clsDesc)

resolveType

protected final Class<?> resolveType(String typeName)
                              throws MappingException

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:

MappingException

createFieldDescriptors

protected final FieldDescriptorImpl[] createFieldDescriptors(ClassMapping clsMap,
                                                             Class<?> javaClass)
                                                      throws MappingException

Create field descriptors. The class mapping information is used to create descriptors for all the fields in the class, except for container fields. Implementations may extend this method to create more suitable descriptors, or create descriptors only for a subset of the fields.

Parameters:

clsMap - The class to which the fields belong.

javaClass - The field mappings.

Throws:

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

getOrigin

protected final ClassMapping getOrigin(ClassMapping clsMap)

Gets the top-most (i.e. without any further 'extends') extends of the given classMapping.

Parameters:

clsMap - The ClassMapping to get the origin for.

Returns:

The top-most extends of the given ClassMapping or the ClassMapping itself if it does not extend any other ClassMapping.

divideFieldDescriptors

protected final FieldDescriptor[] divideFieldDescriptors(FieldDescriptor[] fields,
                                                         String[] ids,
                                                         FieldDescriptor[] identities)

getIdColumnIndex

protected int getIdColumnIndex(FieldDescriptor field,
                               String[] ids)

Finds the index in the given idColumnNames that has the same name as the given field.

Parameters:

field - The FieldDescriptor to find the column index for.

ids - The id columnNames available.

Returns:

The index of the id column name that matches the given field's name or -1 if no such id column name exists.

createFieldDesc

protected FieldDescriptorImpl createFieldDesc(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(Class<?> javaClass,
                                                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(Class fieldType,
                               CollectionHandler colHandler,
                               FieldMapping fieldMap)
                        throws MappingException

Throws:

MappingException

findAccessor

public static final Method findAccessor(Class<?> javaClass,
                                        String methodName,
                                        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 String[] getIdentityColumnNames(String[] ids,
                                                    ClassMapping clsMap)

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

Parameters:

ids - Known identity names.

clsMap - The class mapping.

Returns:

List of identity column names.

isPrimitive

protected static final boolean isPrimitive(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

setInternalContext

public void setInternalContext(InternalContext internalContext)

getInternalContext

public InternalContext getInternalContext()