| /* |
| * Copyright (c) 2006, 2021 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 |
| // |
| package org.eclipse.persistence.jpa.jpql.parser; |
| |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.StringTokenizer; |
| |
| import org.eclipse.persistence.jpa.jpql.WordParser; |
| |
| /** |
| * A <b>JOIN</b> enables the fetching of an association as a side effect of the execution of a query. |
| * A <b>JOIN</b> is specified over an entity and its related entities. |
| * |
| * <div><b>BNF:</b> <code>join ::= join_spec join_association_path_expression [AS] identification_variable</code></div> |
| * <p> |
| * A <b>JOIN FETCH</b> enables the fetching of an association as a side effect of the execution of |
| * a query. A <b>JOIN FETCH</b> is specified over an entity and its related entities. |
| * |
| * <div><b>BNF:</b> <code>fetch_join ::= join_spec FETCH join_association_path_expression</code></div> |
| * <p> |
| * EclipseLink 2.4 |
| * |
| * <div><b>BNF:</b> <code>join_spec { abstract_schema_name | join_association_path_expression } [AS] identification_variable [join_condition]</code></div> |
| * |
| * @version 2.5 |
| * @since 2.3 |
| * @author Pascal Filion |
| */ |
| @SuppressWarnings("nls") |
| public final class Join extends AbstractExpression { |
| |
| /** |
| * The actual <b>AS</b> identifier found in the string representation of the JPQL query. |
| */ |
| private String asIdentifier; |
| |
| /** |
| * Determines whether a whitespace was parsed after <b>AS</b>. |
| */ |
| private boolean hasSpaceAfterAs; |
| |
| /** |
| * Determines whether a whitespace was parsed after the identification variable. |
| */ |
| private boolean hasSpaceAfterIdentificationVariable; |
| |
| /** |
| * Determines whether a whitespace was parsed after <b>JOIN</b>. |
| */ |
| private boolean hasSpaceAfterJoin; |
| |
| /** |
| * Determines whether a whitespace was parsed after the join association path expression. |
| */ |
| private boolean hasSpaceAfterJoinAssociation; |
| |
| /** |
| * The {@link Expression} representing the identification variable. |
| */ |
| private AbstractExpression identificationVariable; |
| |
| /** |
| * The {@link Expression} representing the join association path expression. |
| */ |
| private AbstractExpression joinAssociationPath; |
| |
| /** |
| * The actual <b>JOIN</b> identifier found in the string representation of the JPQL query. |
| */ |
| private String joinIdentifier; |
| |
| /** |
| * The {@link Expression} representing the join <b>ON</b> clause. |
| */ |
| private AbstractExpression onClause; |
| |
| /** |
| * Make sure when parsing the identification variable with tolerance turned on, a the join |
| * condition identifier <b>ON</b> is not parsed. |
| */ |
| private boolean parsingIdentificationVariable; |
| |
| /** |
| * Creates a new <code>Join</code>. |
| * |
| * @param parent The parent of this expression |
| * @param identifier The full <b>JOIN</b> identifier |
| */ |
| public Join(AbstractExpression parent, String identifier) { |
| super(parent, identifier); |
| } |
| |
| @Override |
| public void accept(ExpressionVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| public void acceptChildren(ExpressionVisitor visitor) { |
| getJoinAssociationPath().accept(visitor); |
| getIdentificationVariable().accept(visitor); |
| getOnClause().accept(visitor); |
| } |
| |
| @Override |
| protected void addChildrenTo(Collection<Expression> children) { |
| children.add(getJoinAssociationPath()); |
| children.add(getIdentificationVariable()); |
| children.add(getOnClause()); |
| } |
| |
| @Override |
| protected void addOrderedChildrenTo(List<Expression> children) { |
| |
| String join = getText(); |
| |
| // Break the identifier into multiple identifiers |
| if (join.indexOf(SPACE) != -1) { |
| StringTokenizer tokenizer = new StringTokenizer(join, " ", true); |
| |
| while (tokenizer.hasMoreTokens()) { |
| String token = tokenizer.nextToken(); |
| children.add(buildStringExpression(token)); |
| } |
| } |
| else { |
| children.add(buildStringExpression(join)); |
| } |
| |
| if (hasSpaceAfterJoin) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // Join association path |
| if (joinAssociationPath != null) { |
| children.add(joinAssociationPath); |
| } |
| |
| if (hasSpaceAfterJoinAssociation) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // 'AS' |
| if (asIdentifier != null) { |
| children.add(buildStringExpression(AS)); |
| |
| if (hasSpaceAfterAs) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| } |
| |
| // Identification variable |
| if (identificationVariable != null) { |
| children.add(identificationVariable); |
| } |
| |
| if (hasSpaceAfterIdentificationVariable) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // ON clause |
| if (onClause != null) { |
| children.add(onClause); |
| } |
| } |
| |
| @Override |
| public JPQLQueryBNF findQueryBNF(Expression expression) { |
| |
| if ((joinAssociationPath != null) && joinAssociationPath.isAncestor(expression)) { |
| return getQueryBNF(JoinAssociationPathExpressionBNF.ID); |
| } |
| |
| if ((identificationVariable != null) && identificationVariable.isAncestor(expression)) { |
| return getQueryBNF(IdentificationVariableBNF.ID); |
| } |
| |
| if ((onClause != null) && onClause.isAncestor(expression)) { |
| return getQueryBNF(OnClauseBNF.ID); |
| } |
| |
| return super.findQueryBNF(expression); |
| } |
| |
| /** |
| * Returns the actual <b>AS</b> found in the string representation of the JPQL query, which has |
| * the actual case that was used. |
| * |
| * @return The <b>AS</b> identifier that was actually parsed, or an empty string if it was not |
| * parsed |
| */ |
| public String getActualAsIdentifier() { |
| return asIdentifier; |
| } |
| |
| /** |
| * Returns the actual identifier found in the string representation of the JPQL query, which has |
| * the actual case that was used. |
| * |
| * @return The identifier identifier that was actually parsed |
| */ |
| public String getActualIdentifier() { |
| return joinIdentifier; |
| } |
| |
| /** |
| * Returns the {@link Expression} that represents the identification variable. |
| * |
| * @return The expression that was parsed representing the identification variable |
| */ |
| public Expression getIdentificationVariable() { |
| if (identificationVariable == null) { |
| identificationVariable = buildNullExpression(); |
| } |
| return identificationVariable; |
| } |
| |
| /** |
| * Returns the identifier this expression represents. |
| * |
| * @return Either <b>JOIN</b>, <b>INNER JOIN</b>, <b>LEFT JOIN</b> or <b>LEFT OUTER JOIN</b>. |
| * Although it's possible to have an incomplete identifier if the query is not complete |
| */ |
| public String getIdentifier() { |
| return getText(); |
| } |
| |
| /** |
| * Returns the {@link Expression} that represents the join association path expression. |
| * |
| * @return The expression that was parsed representing the join association path expression |
| */ |
| public Expression getJoinAssociationPath() { |
| if (joinAssociationPath == null) { |
| joinAssociationPath = buildNullExpression(); |
| } |
| return joinAssociationPath; |
| } |
| |
| /** |
| * Returns the {@link Expression} that represents the <b>ON</b> clause if present. |
| * |
| * @return The expression that was parsed representing the identification variable |
| */ |
| public Expression getOnClause() { |
| if (onClause == null) { |
| onClause = buildNullExpression(); |
| } |
| return onClause; |
| } |
| |
| @Override |
| public JPQLQueryBNF getQueryBNF() { |
| return getQueryBNF(JoinBNF.ID); |
| } |
| |
| /** |
| * Determines whether the identifier <b>AS</b> was parsed. |
| * |
| * @return <code>true</code> if the identifier <b>AS</b> was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasAs() { |
| return asIdentifier != null; |
| } |
| |
| /** |
| * Determines whether the identifier <b>FETCH</b> was parsed. |
| * |
| * @return <code>true</code> if the identifier <b>FETCH</b> was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasFetch() { |
| String identifier = getText(); |
| return identifier == JOIN_FETCH || |
| identifier == INNER_JOIN_FETCH || |
| identifier == LEFT_JOIN_FETCH || |
| identifier == LEFT_OUTER_JOIN_FETCH; |
| } |
| |
| /** |
| * Determines whether the identification variable was parsed. |
| * |
| * @return <code>true</code> if the identification variable was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasIdentificationVariable() { |
| return identificationVariable != null && |
| !identificationVariable.isNull() && |
| !identificationVariable.isVirtual(); |
| } |
| |
| /** |
| * Determines whether the join association path expression was parsed. |
| * |
| * @return <code>true</code> if the join association path expression was parsed; <code>false</code> |
| * otherwise |
| */ |
| public boolean hasJoinAssociationPath() { |
| return joinAssociationPath != null && |
| !joinAssociationPath.isNull(); |
| } |
| |
| /** |
| * Determines whether the <b>ON</b> clause was parsed. |
| * |
| * @return <code>true</code> if the <b>ON</b> clause was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasOnClause() { |
| return onClause != null && |
| !onClause.isNull(); |
| } |
| |
| /** |
| * Determines whether a whitespace was parsed after <b>AS</b>. |
| * |
| * @return <code>true</code> if there was a whitespace after <b>AS</b>; <code>false</code> |
| * otherwise |
| */ |
| public boolean hasSpaceAfterAs() { |
| return hasSpaceAfterAs; |
| } |
| |
| /** |
| * Determines whether a whitespace was parsed before <b>ON</b>. |
| * |
| * @return <code>true</code> if there was a whitespace before <b>ON</b>; <code>false</code> |
| * otherwise |
| */ |
| public boolean hasSpaceAfterIdentificationVariable() { |
| return hasSpaceAfterIdentificationVariable; |
| } |
| |
| /** |
| * Determines whether a whitespace was parsed after <b>JOIN</b>. |
| * |
| * @return <code>true</code> if there was a whitespace after <b>JOIN</b>; <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterJoin() { |
| return hasSpaceAfterJoin; |
| } |
| |
| /** |
| * Determines whether a whitespace was parsed after the join association path expression. |
| * |
| * @return <code>true</code> if there was a whitespace after join association path expression; |
| * <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterJoinAssociation() { |
| return hasSpaceAfterJoinAssociation; |
| } |
| |
| /** |
| * Determines whether this {@link Join} is a left join, i.e. {@link Expression#LEFT_JOIN}, |
| * {@link Expression#LEFT_JOIN_FETCH}, {@link Expression#LEFT_OUTER_JOIN}, {@link |
| * Expression#LEFT_OUTER_JOIN_FETCH}. |
| * |
| * @return <code>true</code> if this {@link Join} expression is a {@link Expression#LEFT_JOIN}, |
| * {@link Expression#LEFT_JOIN_FETCH}, {@link Expression#LEFT_OUTER_JOIN}, {@link |
| * Expression#LEFT_OUTER_JOIN_FETCH}; <code>false</code> otherwise |
| */ |
| public boolean isLeftJoin() { |
| String identifier = getIdentifier(); |
| return identifier == LEFT_JOIN || |
| identifier == LEFT_OUTER_JOIN || |
| identifier == LEFT_JOIN_FETCH || |
| identifier == LEFT_OUTER_JOIN_FETCH; |
| } |
| |
| @Override |
| protected boolean isParsingComplete(WordParser wordParser, String word, Expression expression) { |
| |
| // Make sure when parsing the identification variable with tolerance turned on, |
| // a the join condition identifier ON is not parsed |
| if (parsingIdentificationVariable && |
| word.equalsIgnoreCase(ON)) { |
| |
| return true; |
| } |
| |
| return word.equalsIgnoreCase(AS) || |
| word.equalsIgnoreCase(INNER) || |
| word.equalsIgnoreCase(JOIN) || |
| word.equalsIgnoreCase(LEFT) || |
| word.equalsIgnoreCase(OUTER) || |
| super.isParsingComplete(wordParser, word, expression); |
| } |
| |
| @Override |
| protected void parse(WordParser wordParser, boolean tolerant) { |
| |
| // Parse the JOIN identifier |
| joinIdentifier = wordParser.moveForward(getText()); |
| |
| hasSpaceAfterJoin = wordParser.skipLeadingWhitespace() > 0; |
| |
| // Parse the join association path expression |
| if (tolerant) { |
| joinAssociationPath = parse(wordParser, JoinAssociationPathExpressionBNF.ID, tolerant); |
| } |
| // TREAT expression |
| else if (wordParser.startsWithIdentifier(TREAT)) { |
| joinAssociationPath = new TreatExpression(this); |
| joinAssociationPath.parse(wordParser, tolerant); |
| } |
| // Abstract schema name, Collection-valued path expression or state field path expression |
| else { |
| String path = wordParser.word(); |
| |
| if (path.indexOf('.') == -1) { |
| joinAssociationPath = new AbstractSchemaName(this, path); |
| joinAssociationPath.parse(wordParser, tolerant); |
| } |
| else { |
| joinAssociationPath = new CollectionValuedPathExpression(this, path); |
| joinAssociationPath.parse(wordParser, tolerant); |
| } |
| } |
| |
| int count = wordParser.skipLeadingWhitespace(); |
| hasSpaceAfterJoinAssociation = count > 0; |
| |
| // Parse 'AS' |
| if (wordParser.startsWithIdentifier(AS)) { |
| asIdentifier = wordParser.moveForward(AS); |
| hasSpaceAfterAs = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Parse the identification variable |
| parsingIdentificationVariable = true; |
| |
| if (tolerant) { |
| identificationVariable = parse(wordParser, IdentificationVariableBNF.ID, tolerant); |
| } |
| else { |
| String word = wordParser.word(); |
| |
| if ((word.length() > 0) && !isParsingComplete(wordParser, word, null)) { |
| identificationVariable = new IdentificationVariable(this, word); |
| identificationVariable.parse(wordParser, tolerant); |
| } |
| } |
| |
| parsingIdentificationVariable = false; |
| |
| // A JOIN FETCH without '[AS] identification_variable' will not keep the |
| // whitespace after the join association for backward compatibility (for now) |
| if (asIdentifier == null && |
| hasSpaceAfterJoinAssociation && |
| identificationVariable == null && |
| hasFetch() && |
| !wordParser.startsWithIdentifier(ON)) { |
| |
| hasSpaceAfterJoinAssociation = false; |
| wordParser.moveBackward(count); |
| count = 0; |
| } |
| else { |
| count = wordParser.skipLeadingWhitespace(); |
| } |
| |
| // Parse the ON clause |
| if (tolerant) { |
| onClause = parse(wordParser, OnClauseBNF.ID, tolerant); |
| } |
| else if (wordParser.startsWithIdentifier(ON)) { |
| onClause = new OnClause(this); |
| onClause.parse(wordParser, tolerant); |
| } |
| |
| if (onClause != null) { |
| hasSpaceAfterIdentificationVariable = (count > 0); |
| } |
| else { |
| wordParser.moveBackward(count); |
| } |
| } |
| |
| @Override |
| protected void toParsedText(StringBuilder writer, boolean actual) { |
| |
| // Join identifier |
| writer.append(actual ? joinIdentifier : getText()); |
| |
| if (hasSpaceAfterJoin) { |
| writer.append(SPACE); |
| } |
| |
| // Join association path |
| if (joinAssociationPath != null) { |
| joinAssociationPath.toParsedText(writer, actual); |
| } |
| |
| if (hasSpaceAfterJoinAssociation) { |
| writer.append(SPACE); |
| } |
| |
| // 'AS' |
| if (asIdentifier != null) { |
| writer.append(actual ? asIdentifier : AS); |
| |
| if (hasSpaceAfterAs) { |
| writer.append(SPACE); |
| } |
| } |
| |
| // Identification variable |
| if (identificationVariable != null) { |
| identificationVariable.toParsedText(writer, actual); |
| } |
| |
| if (hasSpaceAfterIdentificationVariable) { |
| writer.append(SPACE); |
| } |
| |
| // ON clause |
| if (onClause != null) { |
| onClause.toParsedText(writer, actual); |
| } |
| } |
| } |