Package org.alfresco.repo.domain.propval

Class DefaultPropertyTypeConverter

java.lang.Object

org.alfresco.repo.domain.propval.DefaultPropertyTypeConverter

All Implemented Interfaces:

PropertyTypeConverter

public class DefaultPropertyTypeConverter
extends Object
implements PropertyTypeConverter

Default converter for handling data going to and from the persistence layer.

Properties are stored as a set of well-defined types defined by the enumeration PropertyValueEntity.PersistedType. Ultimately, data can be persisted as BLOB data, but must be the last resort.

Since:

3.2

Author:

Derek Hulley

Field Summary

Fields

Modifier and Type	Field	Description
protected static final Map<Class<?>,PropertyValueEntity.PersistedType>	defaultPersistedTypesByClass	An unmodifiable map of types and how they should be persisted

Constructor Summary

Constructors

Constructor	Description
DefaultPropertyTypeConverter()	Default constructor

Method Summary

Modifier and Type	Method	Description
protected void	addTypeMapping(Class<?> clazz, PropertyValueEntity.PersistedType targetType)	Allow subclasses to add further type mappings specific to the implementation
Serializable	constructInstance(String clazzName)	Construct an instance of an object that was deemed to be PropertyValueEntity.PersistedType.CONSTRUCTABLE.
<T> T	convert(Class<T> targetClass, Serializable value)	Performs the conversion using DefaultTypeConverter but also adds special handling for enum types.
PropertyValueEntity.PersistedType	getPersistentType(Serializable value)	When external to persisted type mappings are not obvious, the persistence framework, before persisting as PropertyValueEntity.PersistedType.SERIALIZABLE, will give the converter a chance to choose how the value must be persisted: PropertyValueEntity.PersistedType.LONG PropertyValueEntity.PersistedType.DOUBLE PropertyValueEntity.PersistedType.STRING PropertyValueEntity.PersistedType.SERIALIZABLE PropertyValueEntity.PersistedType.CONSTRUCTABLE The converter should return PropertyValueEntity.PersistedType.SERIALIZABLE if no further conversions are possible.
protected boolean	isConstructable(Serializable value)	Determines if the value can be adequately recreated (to equality) by creating a new instance.

Methods inherited from class java.lang.Object

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

Field Details

defaultPersistedTypesByClass

protected static final Map<Class<?>,PropertyValueEntity.PersistedType> defaultPersistedTypesByClass

An unmodifiable map of types and how they should be persisted

Constructor Details

DefaultPropertyTypeConverter

public DefaultPropertyTypeConverter()

Default constructor

Method Details

addTypeMapping

protected void addTypeMapping(Class<?> clazz,
 PropertyValueEntity.PersistedType targetType)

Allow subclasses to add further type mappings specific to the implementation

Parameters:

clazz - the class to be converted

targetType - the target persisted type

isConstructable

protected boolean isConstructable(Serializable value)

Determines if the value can be adequately recreated (to equality) by creating a new instance. For example, a java.util.HashMap is constructable provided that the map is empty.

Subclasses can override this to handle any well-known types, and in conjunction with constructInstance(String), even choose to return true if it needs a non-default constructor.

Parameters:

value - the value to check

Returns:

Returns true if the value can be reconstructed by instantiation using a default constructor

constructInstance

public Serializable constructInstance(String clazzName)

Construct an instance of an object that was deemed to be PropertyValueEntity.PersistedType.CONSTRUCTABLE.

Specified by:

constructInstance in interface PropertyTypeConverter

Parameters:

clazzName - the name of the class

Returns:

Returns the new instance

getPersistentType

public PropertyValueEntity.PersistedType getPersistentType(Serializable value)

When external to persisted type mappings are not obvious, the persistence framework, before persisting as PropertyValueEntity.PersistedType.SERIALIZABLE, will give the converter a chance to choose how the value must be persisted:

• PropertyValueEntity.PersistedType.LONG
• PropertyValueEntity.PersistedType.DOUBLE
• PropertyValueEntity.PersistedType.STRING
• PropertyValueEntity.PersistedType.SERIALIZABLE
• PropertyValueEntity.PersistedType.CONSTRUCTABLE

The converter should return PropertyValueEntity.PersistedType.SERIALIZABLE if no further conversions are possible. Implicit in the return value is the converter's ability to do the conversion when required.

If the converter can fully reconstruct an equal instance using just the name of the value's class, then PropertyValueEntity.PersistedType.CONSTRUCTABLE can be used.

Specified by:

getPersistentType in interface PropertyTypeConverter

Parameters:

value - the value that does not have an obvious persistence slot

Returns:

Returns the type of persistence to use

convert

public <T> T convert(Class<T> targetClass,
 Serializable value)

Performs the conversion using DefaultTypeConverter but also adds special handling for enum types.

Specified by:

convert in interface PropertyTypeConverter

Parameters:

targetClass - the desired type to convert to

value - the value to convert

Returns:

Returns the persisted type and value to persist