/*******************************************************************************
* Copyright (c) 1998, 2015 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 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
* 05/24/2011-2.3 Guy Pelletier
* - 345962: Join fetch query when using tenant discriminator column fails.
******************************************************************************/
package org.eclipse.persistence.internal.expressions;
import java.util.*;
import java.io.*;
import org.eclipse.persistence.exceptions.*;
import org.eclipse.persistence.mappings.*;
import org.eclipse.persistence.queries.DatabaseQuery;
import org.eclipse.persistence.internal.helper.*;
import org.eclipse.persistence.expressions.*;
import org.eclipse.persistence.internal.queries.ContainerPolicy;
import org.eclipse.persistence.internal.sessions.AbstractRecord;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.descriptors.ClassDescriptor;
/**
* Used for parameterized expressions, such as expression defined in mapping queries.
*/
public class ParameterExpression extends BaseExpression {
/** The parameter field or name. */
protected DatabaseField field;
/** The opposite side of the relation, this is used for conversion of the parameter using the others mapping. */
protected Expression localBase;
protected boolean isProperty = false;
/** The inferred type of the parameter.
* Please note that the type might not be always initialized to correct value.
* It might be null if not initialized correctly.
*/
Object type;
public ParameterExpression() {
super();
}
public ParameterExpression(String fieldName) {
this(new DatabaseField(fieldName));
}
public ParameterExpression(DatabaseField field) {
super();
this.field = field;
}
// For bug 3107049 ParameterExpression will now be built with a
// default localBase, same as with ConstantExpression.
public ParameterExpression(String fieldName, Expression localbaseExpression, Object type) {
this(new DatabaseField(fieldName), localbaseExpression);
this.type = type;
}
public ParameterExpression(DatabaseField field, Expression localbaseExpression) {
super();
this.field = field;
localBase = localbaseExpression;
}
/**
* INTERNAL:
* Return if the expression is equal to the other.
* This is used to allow dynamic expression's SQL to be cached.
*/
public boolean equals(Object object) {
if (this == object) {
return true;
}
if (!super.equals(object)) {
return false;
}
ParameterExpression expression = (ParameterExpression) object;
return ((getField() == expression.getField()) || ((getField() != null) && getField().equals(expression.getField())));
}
/**
* INTERNAL:
* Compute a consistent hash-code for the expression.
* This is used to allow dynamic expression's SQL to be cached.
*/
public int computeHashCode() {
int hashCode = super.computeHashCode();
if (getField() != null) {
hashCode = hashCode + getField().hashCode();
}
return hashCode;
}
/**
* Return description.
* Used for toString.
*/
public String basicDescription() {
return String.valueOf(getField());
}
/**
* INTERNAL:
* Used for debug printing.
*/
public String descriptionOfNodeType() {
return "Parameter";
}
/**
* This allows for nesting of parameterized expression.
* This is used for parameterizing object comparisons.
*/
public Expression get(String attributeOrQueryKey) {
ParameterExpression expression = new ParameterExpression(attributeOrQueryKey);
expression.setBaseExpression(this);
return expression;
}
/**
* Return the expression builder which is the ultimate base of this expression, or
* null if there isn't one (shouldn't happen if we start from a root)
*/
public ExpressionBuilder getBuilder() {
if (localBase == null) {
//Bug#5097278 Need to return the builder from the base expression if nested.
if (getBaseExpression() != null) {
return ((ParameterExpression)getBaseExpression()).getBuilder();
} else {
return null;
}
}
return localBase.getBuilder();
}
public DatabaseField getField() {
return field;
}
/**
* INTERNAL:
* Used to set the internal field value.
*/
public void setField(DatabaseField field) {
this.field = field;
}
/**
* This allows for nesting of parametrized expression.
* This is used for parameterizing object comparisons.
*/
public Expression getField(DatabaseField field) {
ParameterExpression expression = new ParameterExpression(field);
expression.setBaseExpression(this);
return expression;
}
/**
* The opposite side of the relation, this is used for conversion of the parameter using the others mapping.
*/
public Expression getLocalBase() {
return localBase;
}
/**
* The inferred type of this parameter.
* Please note that the type might not be always initialized to correct value.
* It might be null if not initialized correctly
*/
public Object getType() { return type; }
/**
* The inferred type of this parameter.
* Please note that the type might not be always initialized to correct value.
* It might be null if not initialized correctly
*/
public void setType(Object type) {
this.type = type;
}
/**
* Extract the value from the row.
* This may require recursion if it is a nested parameter.
*/
public Object getValue(AbstractRecord translationRow, AbstractSession session) {
return getValue(translationRow, null, session);
}
/**
* Extract the value from the row.
* This may require recursion if it is a nested parameter.
*/
public Object getValue(AbstractRecord translationRow, DatabaseQuery query, AbstractSession session) {
if (this.field == null) {
return null;
}
Object value = null;
// Check for nested parameters.
if (this.baseExpression != null) {
value = ((ParameterExpression)this.baseExpression).getValue(translationRow, query, session);
if (value == null) {
return null;
}
ClassDescriptor descriptor = session.getDescriptor(value);
//Bug4924639 Aggregate descriptors have to be acquired from their mapping as they are cloned and initialized by each mapping
if (descriptor != null && descriptor.isAggregateDescriptor() && ((ParameterExpression)getBaseExpression()).getLocalBase().isObjectExpression()) {
descriptor = ((ObjectExpression)((ParameterExpression)getBaseExpression()).getLocalBase()).getDescriptor();
}
if (descriptor == null) {
// Bug 245268 validate parameter type against mapping
validateParameterValueAgainstMapping(value, true);
} else {
// For bug 2990493 must unwrap for EJBQL "Select Person(p) where p = ?1"
//if we had to unwrap it make sure we replace the argument with this value
//incase it is needed again, say in conforming.
//bug 3750793
value = descriptor.getObjectBuilder().unwrapObject(value, session);
// Bug 245268 must unwrap before validating parameter type
validateParameterValueAgainstMapping(value, true);
translationRow.put(((ParameterExpression)this.baseExpression).getField(), value);
// The local parameter is either a field or attribute of the object.
DatabaseMapping mapping = descriptor.getObjectBuilder().getMappingForField(this.field);
if (mapping != null) {
value = mapping.valueFromObject(value, this.field, session);
} else {
mapping = descriptor.getObjectBuilder().getMappingForAttributeName(this.field.getName());
if (mapping != null) {
value = mapping.getRealAttributeValueFromObject(value, session);
} else {
DatabaseField queryKeyField = descriptor.getObjectBuilder().getFieldForQueryKeyName(this.field.getName());
if (queryKeyField != null) {
mapping = descriptor.getObjectBuilder().getMappingForField(this.field);
if (mapping != null) {
value = mapping.valueFromObject(value, this.field, session);
}
}
}
}
}
} else {
// Check for null translation row.
if (translationRow == null) {
value = AbstractRecord.noEntry;
} else {
value = translationRow.getIndicatingNoEntry(this.field);
}
// Throw an exception if the field is not mapped. Null may be
// returned if it is a property so check for null and isProperty
if ((value == AbstractRecord.noEntry) || ((value == null) && this.isProperty)) {
if (this.isProperty) {
if (query != null) {
value = query.getSession().getProperty(this.field.getName());
} else {
value = session.getProperty(this.field.getName());
}
if (value == null) {
throw QueryException.missingContextPropertyForPropertyParameterExpression(query, this.field.getName());
}
return value;
}
// Also check the same field, but a different table for table per class inheritance.
// TODO: JPA also allows for field to be renamed in subclasses, this needs to account for that (never has...).
if (translationRow != null) {
value = translationRow.getIndicatingNoEntry(new DatabaseField(this.field.getName()));
}
if ((value == AbstractRecord.noEntry) || (value == null)) {
throw QueryException.parameterNameMismatch(this.field.getName());
}
}
// validate parameter type against mapping
// validate against the localbase (false), since there are no nested params
validateParameterValueAgainstMapping(value, false);
}
// Convert the value to the correct type, i.e. object type mappings.
if (this.localBase != null) {
value = this.localBase.getFieldValue(value, session);
}
return value;
}
public boolean isParameterExpression() {
return true;
}
/**
* INTERNAL:
*/
public boolean isValueExpression() {
return true;
}
/**
* INTERNAL:
* Return true if this parameter expression maps to a property.
*/
public boolean isProperty() {
return isProperty;
}
/**
* INTERNAL:
* Used for cloning.
*/
protected void postCopyIn(Map alreadyDone) {
super.postCopyIn(alreadyDone);
if (getLocalBase() != null) {
setLocalBase(getLocalBase().copiedVersionFrom(alreadyDone));
}
}
/**
* INTERNAL:
* Print SQL onto the stream, using the ExpressionPrinter for context
*/
public void printSQL(ExpressionSQLPrinter printer) {
if (printer.shouldPrintParameterValues()) {
Object value = getValue(printer.getTranslationRow(), printer.getSession());
if (value instanceof Collection) {
printer.printValuelist((Collection)value);
}else{
if(getField() == null) {
printer.printPrimitive(value);
} else {
printer.printParameter(this);
}
}
} else {
if (getField() != null) {
printer.printParameter(this);
}
}
}
/**
* INTERNAL:
* Print java for project class generation
*/
public void printJava(ExpressionJavaPrinter printer) {
((DataExpression)getLocalBase()).getBaseExpression().printJava(printer);
printer.printString(".getParameter(\"" + getField().getQualifiedName() + "\")");
}
/**
* INTERNAL:
* This expression is built on a different base than the one we want. Rebuild it and
* return the root of the new tree
*/
public Expression rebuildOn(Expression newBase) {
ParameterExpression result = (ParameterExpression)clone();
result.setLocalBase(localBase.rebuildOn(newBase));
return result;
}
/**
* INTERNAL:
* Search the tree for any expressions (like SubSelectExpressions) that have been
* built using a builder that is not attached to the query. This happens in case of an Exists
* call using a new ExpressionBuilder(). This builder needs to be replaced with one from the query.
*/
public void resetPlaceHolderBuilder(ExpressionBuilder queryBuilder){
return;
}
/**
* INTERNAL:
* Set to true if this parameter expression maps to a property value.
*/
public void setIsProperty(boolean isProperty) {
this.isProperty = isProperty;
}
/**
* The opposite side of the relation, this is used for conversion of the parameter using the others mapping.
*/
public void setLocalBase(Expression localBase) {
this.localBase = localBase;
}
/**
* INTERNAL:
* Rebuild against the base, with the values of parameters supplied by the context
* expression. This is used for transforming a standalone expression (e.g. the join criteria of a mapping)
* into part of some larger expression. You normally would not call this directly, instead calling twist,
* (see the comment there for more details).
*/
@Override
public Expression twistedForBaseAndContext(Expression newBase, Expression context, Expression oldBase) {
if (isProperty()) {
return context.getProperty(getField());
} else if (newBase == oldBase) {
return this;
} else {
return context.getField(getField());
}
}
/**
* INTERNAL
* Validate the passed parameter against the local base mapping.
* Throw a QueryException if the parameter is of an incorrect class for object comparison.
* Added for Bug 245268
*/
protected void validateParameterValueAgainstMapping(Object value, boolean useBaseExpression) {
Expression queryKey = null;
if (useBaseExpression) {
// used to support validating against the base expression in the case of nesting
ParameterExpression baseExpression = (ParameterExpression)getBaseExpression();
queryKey = baseExpression.getLocalBase();
} else {
// used where we need to simply validate against the local base expression
queryKey = this.getLocalBase();
}
if ((value != null) && !(value instanceof Collection) && (queryKey != null) && queryKey.isObjectExpression()) {
DatabaseMapping mapping = ((ObjectExpression) queryKey).getMapping();
if (mapping != null) {
if (mapping.isCollectionMapping() && queryKey.isMapEntryExpression() && !((MapEntryExpression)queryKey).shouldReturnMapEntry()){
// this is a map key expression, operate on the key
ContainerPolicy cp = ((CollectionMapping)mapping).getContainerPolicy();
Object keyType = cp.getKeyType();
Class keyTypeClass = keyType instanceof Class ? (Class)keyType: ((ClassDescriptor)keyType).getJavaClass();
if (!keyTypeClass.isInstance(value)){
throw QueryException.incorrectClassForObjectComparison(baseExpression, value, mapping);
}
} else if (mapping.isDirectCollectionMapping()) {
// Do not validate direct collection, as type may be convertable.
} else if (mapping.isForeignReferenceMapping() && !mapping.getReferenceDescriptor().getJavaClass().isInstance(value)) {
throw QueryException.incorrectClassForObjectComparison(baseExpression, value, mapping);
}
}
}
}
/**
* INTERNAL:
* Return the value for in memory comparison.
* This is only valid for valueable expressions.
*/
public Object valueFromObject(Object object, AbstractSession session, AbstractRecord translationRow, int valueHolderPolicy, boolean isObjectUnregistered) {
// Run ourselves through the translation row to find the desired value
if (getField() != null) {
return getValue(translationRow, session);
}
throw QueryException.cannotConformExpression();
}
/**
* INTERNAL:
* Used to print a debug form of the expression tree.
*/
public void writeDescriptionOn(BufferedWriter writer) throws IOException {
writer.write(basicDescription());
}
/**
* INTERNAL:
* Append the parameter into the printer.
* "Normal" ReadQuery never has ParameterExpression in it's select clause hence for a "normal" ReadQuery this method is never called.
* The reason this method was added is that UpdateAllQuery (in case temporary storage is required)
* creates a "helper" ReportQuery with ReportItem corresponding to each update expression - and update expression
* may be a ParameterExpression. The call created by "helper" ReportQuery is never executed -
* it's used during construction of insert call into temporary storage.
*/
@Override
public void writeFields(ExpressionSQLPrinter printer, Vector newFields, SQLSelectStatement statement) {
if (printer.getPlatform().isDynamicSQLRequiredForFunctions()) {
printer.getCall().setUsesBinding(false);
}
//print ", " before each selected field except the first one
if (printer.isFirstElementPrinted()) {
printer.printString(", ");
} else {
printer.setIsFirstElementPrinted(true);
}
// This field is a parameter value, so any name can be used.
newFields.addElement(new DatabaseField("*"));
printSQL(printer);
}
/**
* Print the base for debuggin purposes.
*/
public void writeSubexpressionsTo(BufferedWriter writer, int indent) throws IOException {
if (getBaseExpression() != null) {
getBaseExpression().toString(writer, indent);
}
}
}