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package oracle.toplink.essentials.internal.expressions;
import java.util.*;
import java.io.*;
import oracle.toplink.essentials.exceptions.*;
import oracle.toplink.essentials.mappings.*;
import oracle.toplink.essentials.queryframework.*;
import oracle.toplink.essentials.internal.helper.*;
import oracle.toplink.essentials.expressions.*;
import oracle.toplink.essentials.internal.sessions.AbstractRecord;
import oracle.toplink.essentials.internal.sessions.AbstractSession;
import oracle.toplink.essentials.descriptors.ClassDescriptor;
/**
* Used for parameterized expressions, such as expression defined in mapping queries.
*/
public class ParameterExpression extends Expression {
/** 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;
/** The base expression is what the parameter was derived from, used for nested parameters. */
protected Expression baseExpression;
/** The infered 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 baseExpression, Object type) {
this(new DatabaseField(fieldName), baseExpression);
this.type = type;
}
public ParameterExpression(DatabaseField field, Expression baseExpression) {
super();
this.field = field;
localBase = baseExpression;
}
/**
* 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 parametrized expression.
* This is used for parameterizing object comparisons.
*/
public Expression get(String attributeOrQueryKey) {
ParameterExpression expression = new ParameterExpression(attributeOrQueryKey);
expression.setBaseExpression(this);
return expression;
}
/**
* The base expression is what the parameter was derived from.
* This is used for nested parameters.
*/
public Expression getBaseExpression() {
return baseExpression;
}
/**
* 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;
}
/**
* 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 infered 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; }
/**
* Extract the value from the row.
* This may require recusion if it is a nested parameter.
*/
public Object getValue(AbstractRecord translationRow, AbstractSession session) {
if (getField() == null) {
return null;
}
Object value = null;
// Check for nested parameters.
if (getBaseExpression() != null) {
value = ((ParameterExpression)getBaseExpression()).getValue(translationRow, 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.isAggregateDescriptor() && ((ParameterExpression)getBaseExpression()).getLocalBase().isObjectExpression()) {
descriptor = ((ObjectExpression)((ParameterExpression)getBaseExpression()).getLocalBase()).getDescriptor();
}
if (descriptor != null) {
// 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);
translationRow.put(((ParameterExpression)getBaseExpression()).getField(), value);
// The local parameter is either a field or attribute of the object.
DatabaseMapping mapping = descriptor.getObjectBuilder().getMappingForField(getField());
if (mapping != null) {
value = mapping.valueFromObject(value, getField(), session);
} else {
mapping = descriptor.getObjectBuilder().getMappingForAttributeName(getField().getName());
if (mapping != null) {
value = mapping.getRealAttributeValueFromObject(value, session);
} else {
DatabaseField queryKeyField = descriptor.getObjectBuilder().getFieldForQueryKeyName(getField().getName());
if (queryKeyField != null) {
mapping = descriptor.getObjectBuilder().getMappingForField(getField());
if (mapping != null) {
value = mapping.valueFromObject(value, getField(), session);
}
}
}
}
}
} else {
value = translationRow.getIndicatingNoEntry(getField());
//Throw an exception if the field is not mapped
if (value == oracle.toplink.essentials.internal.sessions.AbstractRecord.noEntry) {
throw QueryException.parameterNameMismatch(getField().getName());
}
}
// Convert the value to the correct type, i.e. object type mappings.
if (getLocalBase() != null) {
value = getLocalBase().getFieldValue(value);
}
return value;
}
public boolean isParameterExpression() {
return true;
}
/**
* INTERNAL:
*/
public boolean isValueExpression() {
return true;
}
/**
* INTERNAL:
* Used for cloning.
*/
protected void postCopyIn(Dictionary alreadyDone) {
super.postCopyIn(alreadyDone);
if (getLocalBase() != null) {
setLocalBase(getLocalBase().copiedVersionFrom(alreadyDone));
}
if (getBaseExpression() != null) {
setBaseExpression(getBaseExpression().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(getField() == null) {
printer.printPrimitive(value);
} else {
if (value instanceof Vector) {
printer.printValuelist((Vector)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;
}
/**
* The base expression is what the parameter was derived from.
* This is used for nested parameters.
*/
protected void setBaseExpression(Expression baseExpression) {
this.baseExpression = baseExpression;
}
/**
* 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).
*/
public Expression twistedForBaseAndContext(Expression newBase, Expression context) {
return context.getField(getField());
}
/**
* INTERNAL:
* Return the value for in memory comparison.
* This is only valid for valueable expressions.
*/
public Object valueFromObject(Object object, AbstractSession session, AbstractRecord translationRow, InMemoryQueryIndirectionPolicy 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.
*/
public void writeFields(ExpressionSQLPrinter printer, Vector newFields, SQLSelectStatement statement) {
//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);
}
}
}
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