org.eclipse.persistence.sdo.helper.XPathEngine Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of eclipselink Show documentation
Show all versions of eclipselink Show documentation
EclipseLink build based upon Git transaction f2b9fc5
/*
* Copyright (c) 1998, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.sdo.helper;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import org.eclipse.persistence.oxm.XMLConstants;
import org.eclipse.persistence.sdo.SDOConstants;
import org.eclipse.persistence.sdo.SDODataObject;
import org.eclipse.persistence.exceptions.ConversionException;
import org.eclipse.persistence.exceptions.SDOException;
import org.eclipse.persistence.internal.oxm.XMLConversionManager;
import commonj.sdo.DataObject;
import commonj.sdo.Property;
import commonj.sdo.Sequence;
import commonj.sdo.helper.DataHelper;
import commonj.sdo.impl.HelperProvider;
/**
* Purpose: Perform operations based on SDO XPath against DataObjects.
*
*/
public class XPathEngine {
private static final int SET = 1;
private static final int ISSET = 2;
private static final int UNSET = 3;
protected static XPathEngine defaultXPathEngine;
private XPathEngine() {
}
public static XPathEngine getInstance() {
if (defaultXPathEngine == null) {
defaultXPathEngine = new XPathEngine();
}
return defaultXPathEngine;
}
/**Handle queries about setting status of a property through path base access.
*
* @param path the String representation of path based access
* @param caller the DataObject that pass path information in
* @return true if queried property is set, otherwise false
*/
public boolean isSet(String path, DataObject caller) {
try {
return processPath(path, null, caller, false, ISSET);
// return lastDataObject.isSet(lastProperty);// spec. did not mention exception
} catch (Exception e) {
return false;// spec. did not mention exception
}
}
/**Unset the value of a property through the path base access.
*
* @param path the String representation of path based access
* @param caller the DataObject that pass path information in
*/
public void unset(String path, DataObject caller) {
processPath(path, null, caller, false, UNSET);
}
/**Set a property's value through the path base access.
*
* @param path the String representation of path based access
* @param value the value to be set as the target property's value
* @param caller the DataObject that pass path information in
* @param convertValue boolean used for set if we should convert the value
*/
public void set(String path, Object value, DataObject caller, boolean convertValue) {
processPath(path, value, caller, convertValue, SET);
}
/**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.
*
* @param path the String representation of path based access
* @param caller the DataObject that pass path information in
* @return the value gotten by accessing through path
*/
public Object get(String path, DataObject caller) {// path like "a/b/c"
if ((path == null) || path.equals(SDOConstants.EMPTY_STRING)) {
return null;
}
if (path.equals("..")) {
return caller.getContainer();
}
if (path.equals(SDOConstants.SDO_XPATH_TO_ROOT)) {
return ((SDODataObject)caller).getRootObject();
}
path = getLocalName(path);
int index = path.indexOf('/');
if (index > -1) {
int openBracketIndex = path.indexOf('[');
int closeBracketIndex = path.indexOf(']');
if(index > openBracketIndex && index < closeBracketIndex) {
return getValueForFragment(path, caller);
}
if (index == (path.length() - 1)) {
return getValueForFragment(path.substring(0, index), caller);
} else {
Object value = getValueForFragment(path.substring(0, index), caller);
DataObject currentDataObject = (DataObject) value;
return get(path.substring(index + 1, path.length()), currentDataObject);
}
}
return getValueForFragment(path, caller);
}
/**extract wanted fragment from the string representation of path and pass processed result to
* method setIsSetUnSet for further operation.
*
* @param path the String representation of path based access
* @param value the value to be set as the target property's value
* @param caller the DataObject that pass path information in
* @param convertValue boolean used for set if we should convert the value
* @param _case an int value indicating what kind of operation to use: set, isset or unset.
* @return true if operation is isset and property's value is set, otherwise false.
*/
private boolean processPath(String path, Object value, DataObject caller, boolean convertValue, int _case) {
path = getLocalName(path);
int lastSlashIndex = path.lastIndexOf('/');
String frag;
if (-1 < lastSlashIndex) {// case 1: a/b/c
frag = path.substring(lastSlashIndex + 1);
return setIsSetUnSet(frag, path, caller, value, lastSlashIndex, convertValue, _case);
} else {// case 2 : "a"
frag = path;
return setIsSetUnSet(frag, path, caller, value, lastSlashIndex, convertValue, _case);
}
}
/**According to the requirement, correspondingly perform isset, unset or set function.
*
* @param frag one string fragment in the path
* @param path the String representation of path based access
* @param caller the DataObject that pass path information in
* @param value the value to be set as the target property's value
* @param lastSlashIndex the last index of '/' in the path string
* @param convertValue boolean used for set if we should convert the value
* @param _case an int value indicating what kind of operation to use: set, isset or unset.
* @return true if operation is isset and property's value is set, otherwise false.
*/
private boolean setIsSetUnSet(String frag, String path, DataObject caller, Object value, int lastSlashIndex, boolean convertValue, int _case) {
int indexOfDot = frag.lastIndexOf('.');
int indexOfOpenBracket = frag.lastIndexOf('[');
int indexOfCloseBracket = frag.lastIndexOf(']');
int numInLastProperty = getNumberInFrag(frag, indexOfDot, indexOfOpenBracket, indexOfCloseBracket);
String lastPropertyName = getPropertyNameInFrag(frag, numInLastProperty, indexOfDot, indexOfOpenBracket);// get last property name on path for case 1
DataObject lastDataObject;
if (-1 < lastSlashIndex) {
Object lastObject = get(path.substring(0, lastSlashIndex), caller);// get last dataobject on path
// If trying to access a list element from a null list, this object will be
// an instance of ListWrapper, not DataObject, but the error message is the same
// as if it was a null DataObject
if (lastObject == null || lastObject instanceof ListWrapper) {
throw SDOException.cannotPerformOperationOnProperty(lastPropertyName, path);
}
lastDataObject = (SDODataObject) lastObject;
} else {
lastDataObject = caller;
}
Property lastProperty = lastDataObject.getInstanceProperty(lastPropertyName);// get property of this dataobject
switch (_case) {
case SET:
if (lastProperty == null) {
lastProperty = ((SDODataObject)lastDataObject).defineOpenContentProperty(lastPropertyName, value);
}if(lastProperty != null){
set(lastProperty, lastDataObject, numInLastProperty, value,convertValue);
}
return false;
case ISSET:
if(lastProperty == null){
return false;
}
return isSet(lastProperty, lastDataObject);
case UNSET:
if(lastProperty == null){
return false;
}
unSet(lastProperty, lastDataObject, numInLastProperty);
return false;
default:
return false;
}
}
/** Method that returns whether a property is set.
*
* @param lastProperty the property to queries.
* @param lastDataObject the DataObject, owner of the queried property
* @return return true, if property's value is set, otherwise false.
*/
private boolean isSet(Property lastProperty, DataObject lastDataObject) {
return lastDataObject.isSet(lastProperty);
}
/** Method that unset a certain property's value.
*
* @param lastProperty the property to queries.
* @param lastDataObject the DataObject, owner of the queried property
*/
private void unSet(Property lastProperty, DataObject lastDataObject, int numInLastProperty) {
if (numInLastProperty == -1) {
lastDataObject.unset(lastProperty);
} else {
List objects = lastDataObject.getList(lastProperty);
if (numInLastProperty <= objects.size()) {
objects.remove(numInLastProperty);
}
}
}
/** Set a property's value.
*
* @param lastProperty the property to queries.
* @param lastDataObject the DataObject, owner of the queried property
* @param numInLastProperty the index number in the value list of the above property
* @param value the value to be set as the target property's value
* @param convertValue boolean used for set if we should convert the value
*/
private void set(Property lastProperty, DataObject lastDataObject, int numInLastProperty, Object value, boolean convertValue) {
if (numInLastProperty == -1) {
if (lastDataObject != null) {
if(convertValue){
DataHelper dataHelper = ((SDODataObject)lastDataObject).getType().getHelperContext().getDataHelper();
value = dataHelper.convert(lastProperty, value);
}
lastDataObject.set(lastProperty, value);
} else {
throw new IllegalArgumentException("lastDataObject is null");
}
} else {// case like set("a/b.1", List) will cause a list be added into a existed list
List objects = lastDataObject.getList(lastProperty);
if (convertValue) {
DataHelper dataHelper = ((SDODataObject)lastDataObject).getType().getHelperContext().getDataHelper();
value = dataHelper.convert(lastProperty.getType(), value);
}
Sequence seq = lastDataObject.getSequence();
if (seq != null) {
seq.setValue(numInLastProperty, value);
} else {
objects.set(numInLastProperty, value);
}
}
}
private String getLocalName(String qualifiedName) {
int index = qualifiedName.indexOf(':');
if (index > -1) {
int bracketIndex = qualifiedName.indexOf('[');
if(bracketIndex > -1 && bracketIndex < index) {
return qualifiedName;
}
String local = qualifiedName.substring(index + 1, qualifiedName.length());
return local;
} else {
return qualifiedName;
}
}
/** Process the passed in fragment, extract the position information if available,
* acquire the property name hidden in this fragment and check if this fragment is
* actually query base. Then perform corresponding actions to access values.
*
* @param frag one string fragment in the path
* @param caller a DataObject that originally took the path information
* @return values to be accessed
*/
private Object getValueForFragment(String frag, DataObject caller) {
int indexOfDot = frag.lastIndexOf('.');
int indexOfOpenBracket = frag.indexOf('[');
int indexOfCloseBracket = frag.lastIndexOf(']');
int position = getNumberInFrag(frag, indexOfDot, indexOfOpenBracket, indexOfCloseBracket);
String propertyName = getPropertyNameInFrag(frag, position, indexOfDot, indexOfOpenBracket);
int equalSignIndex = isQueryPath(frag, indexOfOpenBracket, indexOfCloseBracket);
if (equalSignIndex == -1) {// not query path, note:
return getObjectByFragment(propertyName, position, caller);
}
return getDataObjectFromQuery(frag, indexOfOpenBracket, indexOfCloseBracket, equalSignIndex, caller, propertyName);
}
/** Extract the property name hidden in a fragment of path
*
* @param frag one string fragment in the path
* @param position the index of values to be accessed
* @param indexOfDot the index of . in the fragment
* @param indexOfOpenBracket the indexof [ in the fragment
* @return the property name hidden in this fragment
*/
private String getPropertyNameInFrag(String frag, int position, int indexOfDot, int indexOfOpenBracket) {
int startIndex = 0;
int atIndex = frag.indexOf('@');
if (atIndex != -1 && (indexOfOpenBracket == -1 || atIndex < indexOfOpenBracket)) {
startIndex += 1;
}
if (indexOfOpenBracket != -1) {
return frag.substring(startIndex, indexOfOpenBracket);
}
if ((indexOfDot != -1) && (position != -1)) {
return frag.substring(startIndex, indexOfDot);
}
return frag.substring(startIndex);
}
/** Judge if positional path belongs to bracket case or dot case, then perform
* different actions.
*
* @param frag one string fragment in the path
* @param indexOfDot the index of . in the fragment
* @param indexOfOpenBracket the index of [ in the fragment
* @param indexOfCloseBracket the index of ] in the fragment
* @return the position hidden in fragment
*/
private int getNumberInFrag(String frag, int indexOfDot, int indexOfOpenBracket, int indexOfCloseBracket) {
if ((indexOfOpenBracket != -1) && (indexOfCloseBracket != -1) && (indexOfOpenBracket < indexOfCloseBracket)) {
return acquireNumberInBrackets(frag, indexOfOpenBracket, indexOfCloseBracket);
}
if (indexOfDot != -1) {
return acquireNumberAtDot(frag, indexOfDot);
}
return -1;
}
/**check if information in brackets is qury or not.
*
* @param frag a fragment in path
* @param openBracketIndex index of open bracket in fragment
* @param closeBracketIndex index of close bracket in fragment
* @return
*/
private int isQueryPath(String frag, int openBracketIndex, int closeBracketIndex) {
if ((openBracketIndex != -1) && (closeBracketIndex != -1) && (openBracketIndex < closeBracketIndex)) {
return frag.substring(openBracketIndex, closeBracketIndex).indexOf('=');
}
return -1;
}
// extract value from query and acquire dataobject that meets this requirement
/**Access the DataObject value by using the fragment containing query informations.
*
* @param frag one string fragment in the path
* @param openBracketIndex the index of open bracket in a fragment
* @param closeBracketIndex the index of close bracket in a fragment
* @param equalsignIndex the index of equalsign in string fragment quoted by brackets
* @param caller the DataObject that passes the path information in
* @param callerProperty the name of the property
* @return the DataObject as value of the property having name as the above callerProperty
*/
private DataObject getDataObjectFromQuery(String frag, int openBracketIndex, int closeBracketIndex, int equalsignIndex, DataObject caller, String callerProperty) {
try {
// trim off any whitespace for property names
String propertyNameOfQryDataObject = frag.substring(openBracketIndex + 1, equalsignIndex + openBracketIndex).trim();
List objects = caller.getList(caller.getInstanceProperty(callerProperty));
String query = frag.substring(equalsignIndex + openBracketIndex + 1, closeBracketIndex);
String value = null;
int firstQuoteIndex = query.indexOf('\'');
int lastQuoteIndex = query.lastIndexOf('\'');
if ((firstQuoteIndex == -1) && (lastQuoteIndex == -1)) {// !! note: case: [number=1'23'] is assume not to happen !!
firstQuoteIndex = query.indexOf("\"");
lastQuoteIndex = query.lastIndexOf("\"");
}
if ((firstQuoteIndex != -1) && (lastQuoteIndex != -1) && (firstQuoteIndex < lastQuoteIndex)) {// quoted string existed
value = query.substring(firstQuoteIndex + 1, lastQuoteIndex);
} else {
// if the value is not enclosed on quotes, trim off any whitespace
value = query.trim();
}
Iterator iterObjects = objects.iterator();
Object queryValue = value;
Object actualValue = null;
while (iterObjects.hasNext()) {
DataObject cur = (DataObject)iterObjects.next();
Property p = cur.getInstanceProperty(propertyNameOfQryDataObject);
if(p != null){
try {
queryValue = XMLConversionManager.getDefaultXMLManager().convertObject(queryValue, p.getType().getInstanceClass());
} catch (ConversionException e) {
//do nothing, skip
}
if (!p.isMany()) {
actualValue = cur.get(p);
if (actualValue.equals(queryValue)) {
return cur;
}
} else {// case p is many type
List values = cur.getList(p);
Iterator iterValues = values.iterator();
while (iterValues.hasNext()) {
actualValue = iterValues.next();
if (actualValue.equals(queryValue)) {
return cur;
}
}
}
}
}
return null;
} catch (IllegalArgumentException e) {
return null;
}
}
// process a portion of path, find out if it is positional or not.
// if it is, then check it is using '.' or '[ ]' and perform corresponding
// process.
/** Check if position exists, then either acquire value through position or directly.
*
* @param propertyName the name of property of the caller
* @param position the index of values to be accessed
* @param caller the DataObject containing property with the passed in property name
* @return the values to be accessed
*/
private Object getObjectByFragment(String propertyName, int position, DataObject caller) {
Property prop = caller.getInstanceProperty(propertyName);
if (prop == null){
return null;
}
if (prop.isMany() && position > -1) {
return caller.getList(prop).get(position);
} else {
return caller.get(prop);
}
}
/** Extract position (index) from a bracket fragment of path
*
* @param frag a fragment of path
* @param openBracketIndex the index of [ in path
* @param closeBracketIndex the index of ] in path
* @return the index hidden in fragment
*/
private int acquireNumberInBrackets(String frag, int openBracketIndex, int closeBracketIndex) {
String number = frag.substring(openBracketIndex + 1, closeBracketIndex);
if (number.matches("[1-9][0-9]*")) {
return Integer.parseInt(number) - 1;
//value = number;
}
return -1;// throw Illegal path?
}
/**Extract the position (index) from a dot fragment of path
*
* @param frag a fragment of path
* @param dotIndex the index of . in path
* @return the index hidden in the fragment
*/
private int acquireNumberAtDot(String frag, int dotIndex) {
int value = -1;
String position = frag.substring(dotIndex + 1);
if (position.matches("[0-9]+")) {
value = Integer.parseInt(position);
//value = position;
}
return value;
}
// dataobject a's property a has value dataobject b, dataobject b's property b has value dataobject c,
//dataobject c's property c has value boolean,
/** access the wanted values through path and convert it into required java class.
* If conversion is not supported, exception is thrown.
*
* @param path string representation of accessing path
* @param cls the java class that accessed value is to be converted to
* @param caller the DataObject that pass the path in
* @return values to be accessed
* @throws ClassCastException
*/
public Object convertObjectToValueByPath(String path, Class cls, DataObject caller) throws ClassCastException {
if (null == path || XMLConstants.EMPTY_STRING.equals(path)) {
throw new ClassCastException("Attempting null value conversion.");
}
try {
int lastSlashIndex = path.lastIndexOf('/');
SDODataObject lastDataObject;
String lastPropertyName;
Property lastProperty;
int numInLastProperty = -1;
// to do: if "/" or ".." lastDataObject = container or root
if (-1 < lastSlashIndex) {// case 1 "a/b/c"
String frag = path.substring(lastSlashIndex + 1);
int indexOfDot = frag.lastIndexOf('.');
int indexOfOpenBracket = frag.lastIndexOf('[');
int indexOfCloseBracket = frag.lastIndexOf(']');
numInLastProperty = getNumberInFrag(frag, indexOfDot, indexOfOpenBracket, indexOfCloseBracket);
lastPropertyName = getPropertyNameInFrag(frag, numInLastProperty, indexOfDot, indexOfOpenBracket);//getPropertyNameFromFragment(path.substring(lastSlashIndex + 1));// get last property name on path for case 1
lastDataObject = (SDODataObject)caller.getDataObject(path.substring(0, lastSlashIndex));// get last dataobject on path
if(lastDataObject == null){
return null;
}
lastProperty = lastDataObject.getInstanceProperty(lastPropertyName);// get property of this dataobject
} else {// case 2 "a"
//to do: call eextractPositionAndPropertyName() here
String frag = path;
int indexOfDot = frag.lastIndexOf('.');
int indexOfOpenBracket = frag.lastIndexOf('[');
int indexOfCloseBracket = frag.lastIndexOf(']');
numInLastProperty = getNumberInFrag(frag, indexOfDot, indexOfOpenBracket, indexOfCloseBracket);
lastPropertyName = getPropertyNameInFrag(frag, numInLastProperty, indexOfDot, indexOfOpenBracket);//getPropertyNameFromFragment(path);// get last property name on path for case 1
lastDataObject = (SDODataObject)caller;
if(lastDataObject == null){
return null;
}
lastProperty = caller.getInstanceProperty(lastPropertyName);// get property of this dataobject
}
if ((lastProperty != null) && (cls == Date.class) && lastProperty.getType().equals(SDOConstants.SDO_STRING)) {// in case getDate, for string property, use DataHelper
DataHelper dHelper = HelperProvider.getDefaultContext().getDataHelper();
String dateString;
if (numInLastProperty == -1) {
dateString = (String)lastDataObject.get(lastProperty);
} else {
dateString = (String)(lastDataObject.getList(lastProperty)).get(numInLastProperty);
}
return dHelper.toDate(dateString);
}
return lastDataObject.convertObjectToValue(lastProperty, numInLastProperty, cls);
} catch (IllegalArgumentException e) {// according to exception table 1st row, when get(Property) and get(Index) throw IllegalArgument, get(String) return null
throw new ClassCastException("Conversion is not supported.");
//return null;
}
}
}