Module org.eclipse.persistence.sdo

Package org.eclipse.persistence.sdo.helper

Class XPathEngine

java.lang.Object

org.eclipse.persistence.sdo.helper.XPathEngine

public class XPathEngine
extends Object

Purpose: Perform operations based on SDO XPath against DataObjects.

Field Summary

Fields

Modifier and Type	Field	Description
protected static XPathEngine	defaultXPathEngine

Method Summary

Modifier and Type	Method	Description
Object	convertObjectToValueByPath(String path, Class<?> cls, DataObject caller)	access the wanted values through path and convert it into required java class.
Object	get(String path, DataObject caller)	When accessing values corresponding to properties of DataObject by path base accessors, the accessed getters will pass informations to this method to process information and acquire wanted values.
static XPathEngine	getInstance()
boolean	isSet(String path, DataObject caller)	Handle queries about setting status of a property through path base access.
void	set(String path, Object value, DataObject caller, boolean convertValue)	Set a property's value through the path base access.
void	unset(String path, DataObject caller)	Unset the value of a property through the path base access.

Methods inherited from class java.lang.Object

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

Field Detail

defaultXPathEngine

protected static XPathEngine defaultXPathEngine

Method Detail

getInstance

public static XPathEngine getInstance()

isSet

public boolean isSet(String path,
                     DataObject caller)

Handle queries about setting status of a property through path base access.

Parameters:

path - the String representation of path based access

caller - the DataObject that pass path information in

Returns:

true if queried property is set, otherwise false

unset

public void unset(String path,
                  DataObject caller)

Unset the value of a property through the path base access.

Parameters:

path - the String representation of path based access

caller - the DataObject that pass path information in

set

public void set(String path,
                Object value,
                DataObject caller,
                boolean convertValue)

Set a property's value through the path base access.

Parameters:

path - the String representation of path based access

value - the value to be set as the target property's value

caller - the DataObject that pass path information in

convertValue - boolean used for set if we should convert the value

get

public Object get(String path,
                  DataObject caller)

When accessing values corresponding to properties of DataObject by path base accessors, the accessed getters will pass informations to this method to process information and acquire wanted values.

Parameters:

path - the String representation of path based access

caller - the DataObject that pass path information in

Returns:

the value gotten by accessing through path

convertObjectToValueByPath

public Object convertObjectToValueByPath(String path,
                                         Class<?> cls,
                                         DataObject caller)
                                  throws ClassCastException

access the wanted values through path and convert it into required java class. If conversion is not supported, exception is thrown.

Parameters:

path - string representation of accessing path

cls - the java class that accessed value is to be converted to

caller - the DataObject that pass the path in

Returns:

values to be accessed

Throws:

ClassCastException