/*******************************************************************************
* Copyright (c) 1998, 2008 Oracle. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.oxm.mappings;
import org.eclipse.persistence.exceptions.ConversionException;
import org.eclipse.persistence.exceptions.DescriptorException;
import org.eclipse.persistence.internal.helper.DatabaseField;
import org.eclipse.persistence.internal.queries.JoinedAttributeManager;
import org.eclipse.persistence.internal.sessions.AbstractRecord;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.oxm.XMLField;
import org.eclipse.persistence.mappings.foundation.AbstractDirectMapping;
import org.eclipse.persistence.oxm.mappings.converters.XMLConverter;
import org.eclipse.persistence.oxm.mappings.nullpolicy.AbstractNullPolicy;
import org.eclipse.persistence.oxm.mappings.nullpolicy.NullPolicy;
import org.eclipse.persistence.oxm.record.XMLRecord;
import org.eclipse.persistence.queries.ObjectBuildingQuery;
/**
* <p>XML Direct Mappings map a Java attribute directly to XML attribute or text node.
*
* <p><b>XML Direct Mappings can be used in the following scenarios</b>:<ul>
* <li>Mapping to a Text Node</li>
* <li>Mapping to an Attribute</li>
* <li>Mapping to a Specified Schema Type</li>
* <li>Mapping to a List Field</li>
* <li>Mapping to a Union Field</li>
* <li>Mapping to a Union of Lists</li>
* <li>Mapping to a Union of Unions</li>
* <li>Mapping with a Simple Type Translator</li>
* </ul>
*
* <p><b>Setting the XPath</b>: TopLink XML mappings make use of XPath statements to find the relevant
* data in an XML document. The XPath statement is relative to the context node specified in the descriptor.
* The XPath may contain node type, path, and positional information. The XPath is specified on the
* mapping using the <code>setXPath</code> method.
*
* <p>The following XPath statements may be used to specify the location of XML data relating to an object's
* name attribute:
*
* <p><table border="1">
* <tr>
* <th id="c1" align="left">XPath</th>
* <th id="c2" align="left">Description</th>
* </tr>
* <tr>
* <td headers="c1">@name</td>
* <td headers="c2">The "@" character indicates that the node is an attribute.</td>
* </tr>
* <tr>
* <td headers="c1">text()</td>
* <td headers="c2">"text()" indicates that the node is a text node. In this case the name value in the
* text node belongs to the context node.</td>
* </tr>
* <tr>
* <td headers="c1">full-name/text()</td>
* <td headers="c2">The name information is stored in the text node of the full-name element.</td>
* </tr>
* <tr>
* <td headers="c1" nowrap="true">personal-info/name/text()</td>
* <td headers="c2">The XPath statement may be used to specify any valid path.</td>
* </tr>
* <tr>
* <td headers="c1">name[2]/text()</td>
* <td headers="c2">The XPath statement may contain positional information. In this case the name
* information is stored in the text node of the second occurrence of the name element.</td>
* </tr>
* </table>
*
* <p><b>Mapping to a Specific Schema Type</b>: In most cases TopLink can determine the target format in the
* XML document. However, there are cases where you must specify which one of a number of possible targets
* TopLink should use. For example, a java.util.Calendar could be marshalled to a schema date, time, or dateTime,
* or a byte[] could be marshalled to a schema hexBinary or base64Binary node.
*
* <!--
* <?xml version="1.0" encoding="UTF-8"?>
* <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
* <xsd:element name="customer" type="customer-type"/>
* <xsd:complexType name="customer-type">
* <xsd:sequence>
* <xsd:element name="picture" type="xsd:hexBinary"/>
* <xsd:element name="resume" type="xsd:base64Binary"/>
* </xsd:sequence>
* </xsd:complexType>
* </xsd:schema>
* -->
*
* <p><em>XML Schema</em><br>
* <code>
* <?xml version="1.0" encoding="UTF-8"?><br>
* <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"><br>
* <xsd:element name="customer" type="customer-type"/><br>
* <xsd:complexType name="customer-type"><br>
* <xsd:sequence><br>
* <xsd:element name="picture" type="xsd:hexBinary"/><br>
* <xsd:element name="resume" type="xsd:base64Binary"/><br>
* </xsd:sequence><br>
* </xsd:complexType><br>
* </xsd:schema><br>
* </code>
*
* <p><em>Code Sample</em><br>
* <code>
* XMLDirectMapping pictureMapping = new XMLDirectMapping();<br>
* pictureMapping.setAttributeName("picture");<br>
* pictureMapping.setXPath("picture/text()");<br>
* XMLField pictureField = (XMLField) pictureMapping.getField();<br>
* pictureField.setSchemaType(XMLConstants.HEX_BINARY_QNAME);<br>
* </code>
*
* <p><b>Mapping to a Union Field</b>:
*
* <!--
* <?xml version="1.0" encoding="UTF-8"?>
* <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
* <xsd:element name="customer" type="customer-type"/>
* <xsd:complexType name="customer-type">
* <xsd:sequence>
* <xsd:element name="shoe-size" type="size-type"/>
* </xsd:sequence>
* </xsd:complexType>
* <xsd:simpleType name="size-type">
* <xsd:union memberTypes="xsd:decimal xsd:string"/>
* </xsd:simpleType>
* </xsd:schema>
* -->
*
* <p><em>XML Schema</em><br>
* <code>
* <?xml version="1.0" encoding="UTF-8"?><br>
* <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"><br>
* <xsd:element name="customer" type="customer-type"/><br>
* <xsd:complexType name="customer-type"><br>
* <xsd:sequence><br>
* <xsd:element name="shoe-size" type="size-type"/><br>
* </xsd:sequence><br>
* </xsd:complexType><br>
* <xsd:simpleType name="size-type"><br>
* <xsd:union memberTypes="xsd:decimal xsd:string"/><br>
* </xsd:simpleType><br>
* </xsd:schema><br>
* </code>
*
* <p><em>Code Sample</em><br>
* <code>
* XMLDirectMapping shoeSizeMapping = new XMLDirectMapping();<br>
* shoeSizeMapping.setAttributeName("shoeSize");<br>
* XMLUnionField shoeSizeField = new XMLUnionField();<br>
* shoeSizeField.setXPath("shoe-size/text()");<br>
* shoeSizeField.addSchemaType(XMLConstants.DECIMAL_QNAME);<br>
* shoeSizeField.addSchemaType(XMLConstants.STRING_QNAME);<br>
* shoeSizeMapping.setField(shoeSizeField);<br>
* </code>
*
* <p><b>Preserving the Node Type</b>: If the type of a node is not defined in your XML schema,
* you can configure an XML Direct Mapping to use the xsi:type attribute to provide type information.
*
* <p><em>Code Sample</em><br>
* <code>
* XMLDirectMapping numberMapping = new XMLDirectMapping();<br>
* numberMapping.setAttributeName("number");<br>
* numberMapping.setXPath("number/text()");<br>
* XMLField numberField = (XMLField) numberMapping.getField();<br>
* numberField.setIsTypedTextField(true);<br>
* </code>
*
* <p><b>More Information</b>: For more information about using the XML Direct Mapping, see the
* "Understanding XML Mappings" chapter of the Oracle TopLink Developer's Guide.
*
* @since Oracle TopLink 10<i>g</i> Release 2 (10.1.3)
*/
public class XMLDirectMapping extends AbstractDirectMapping implements XMLMapping, XMLNillableMapping {
/** Empty String identifier */
protected static final String EMPTY_STRING = "";
AbstractNullPolicy nullPolicy;
public boolean isCDATA;
public XMLDirectMapping() {
super();
// The default policy is NullPolicy
nullPolicy = new NullPolicy();
isCDATA = false;
}
/**
* Set the AbstractNullPolicy on the mapping<br>
* The default policy is NullPolicy.<br>
*
* @param aNullPolicy
*/
public void setNullPolicy(AbstractNullPolicy aNullPolicy) {
nullPolicy = aNullPolicy;
}
/**
* INTERNAL:
* Get the AbstractNullPolicy from the Mapping.<br>
* The default policy is NullPolicy.<br>
* @return
*/
public AbstractNullPolicy getNullPolicy() {
return nullPolicy;
}
/**
* INTERNAL:
*/
public boolean isXMLMapping() {
return true;
}
/**
* Set the Mapping field name attribute to the given XPath String
* @param xpathString String
*/
public void setXPath(String xpathString) {
if ((xpathString.indexOf("@") == -1) && (!xpathString.endsWith("text()"))) {
xpathString += "/text()";
}
setField(new XMLField(xpathString));
}
public void initialize(AbstractSession session) throws DescriptorException {
super.initialize(session);
((XMLField)getField()).setIsCDATA(this.isCDATA());
}
/**
* INTERNAL:
* Allows for subclasses to convert the attribute value.
*/
public Object getAttributeValue(Object fieldValue, AbstractSession session, XMLRecord record) {
// Unmarshal DOM
// If attribute is empty string representing (null) then return the nullValue
if (EMPTY_STRING.equals(fieldValue)) {
fieldValue = null;
}
// PERF: Direct variable access.
Object attributeValue = fieldValue;
// If attribute is absent check the policy
if(attributeValue == XMLRecord.noEntry) {
if(!getNullPolicy().getIsSetPerformedForAbsentNode()) {
return attributeValue;
} else {
fieldValue = null;
attributeValue = null;
}
}
// Allow for user defined conversion to the object value.
if (hasConverter()) {
if (getConverter() instanceof XMLConverter) {
attributeValue = ((XMLConverter)getConverter()).convertDataValueToObjectValue(attributeValue, session, record.getUnmarshaller());
} else {
attributeValue = getConverter().convertDataValueToObjectValue(attributeValue, session);
}
} else {
// PERF: Avoid conversion check when not required.
if ((attributeValue == null) || (attributeValue.getClass() != this.attributeObjectClassification)) {
try {
attributeValue = session.getDatasourcePlatform().convertObject(attributeValue, this.attributeClassification);
} catch (ConversionException e) {
throw ConversionException.couldNotBeConverted(this, getDescriptor(), e);
}
}
}
if (attributeValue == null) {// Translate default null value, conversion may have produced null.
attributeValue = this.nullValue;
}
return attributeValue;
}
/**
* INTERNAL:
* Convert the attribute value to a field value.
* Process any converter if defined, and check for null values.
*/
public Object getFieldValue(Object attributeValue, AbstractSession session, XMLRecord record) {
// Marshal
// PERF: This method is a major performance code point,
// so has been micro optimized and uses direct variable access.
Object fieldValue = attributeValue;
if ((this.nullValue != null) && (this.nullValue.equals(fieldValue))) {
return null;
}
// Allow for user defined conversion to the object value.
if (hasConverter()) {
if (getConverter() instanceof XMLConverter) {
fieldValue = ((XMLConverter)getConverter()).convertObjectValueToDataValue(fieldValue, session, record.getMarshaller());
} else {
fieldValue = getConverter().convertObjectValueToDataValue(fieldValue, session);
}
}
Class fieldClassification = getFieldClassification(getField());
// PERF: Avoid conversion if not required.
if ((fieldValue != null) && (fieldClassification != fieldValue.getClass())) {
try {
fieldValue = session.getPlatform(descriptor.getJavaClass()).convertObject(fieldValue, fieldClassification);
} catch (ConversionException exception) {
throw ConversionException.couldNotBeConverted(this, descriptor, exception);
}
}
return fieldValue;
}
/**
* Get the XPath String
* @return String the XPath String associated with this Mapping
*/
public String getXPath() {
return getFieldName();
}
/**
* INTERNAL:
* Return the mapping's attribute value from the row.
* The execution session is passed for the case of building a UnitOfWork clone
* directly from a row, the session set in the query will not know which platform to use
* for converting the value. Allows the correct session to be passed in.
*/
public Object valueFromRow(AbstractRecord row, JoinedAttributeManager joinManager, ObjectBuildingQuery query, AbstractSession executionSession) {
// PERF: Direct variable access.
return getAttributeValue(row.getIndicatingNoEntry(this.field), executionSession, (XMLRecord)row);
}
/**
* INTERNAL:
* Get a value from the object and set that in the respective field of the row.
*/
public void writeFromObjectIntoRow(Object object, AbstractRecord row, AbstractSession session) {
if (isReadOnly()) {
return;
}
writeSingleValue(getAttributeValueFromObject(object), object, (XMLRecord)row, session);
}
protected void writeValueIntoRow(AbstractRecord row, DatabaseField aField, Object fieldValue) {
row.put(getField(), fieldValue);
}
public void writeSingleValue(Object value, Object parent, XMLRecord row, AbstractSession session) {
Object fieldValue = getFieldValue(value, session, row);
writeValueIntoRow(row, getField(), fieldValue);
}
public void setAttributeValueInObject(Object object, Object value) throws DescriptorException {
// PERF: Direct variable access.
try {
if(value == XMLRecord.noEntry) {
return;
}
this.attributeAccessor.setAttributeValueInObject(object, value);
} catch (DescriptorException exception) {
exception.setMapping(this);
throw exception;
}
}
public void setIsCDATA(boolean CDATA) {
isCDATA = CDATA;
}
public boolean isCDATA() {
return isCDATA;
}
}