| /* |
| * 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.List; |
| import org.eclipse.persistence.jpa.jpql.ExpressionTools; |
| import org.eclipse.persistence.jpa.jpql.WordParser; |
| |
| /** |
| * The <b>TRIM</b> function trims the specified character from a string. If the character to be |
| * trimmed is not specified, it is assumed to be space (or blank). The optional <code>trim_character</code> |
| * is a single-character string literal or a character-valued input parameter (i.e., char or |
| * Character). If a trim specification is not provided, <b>BOTH</b> is assumed. The <b>TRIM</b> |
| * function returns the trimmed string. |
| * <p> |
| * JPA 1.0, 2.0: |
| * <div><b>BNF:</b> <code>expression ::= TRIM([[trim_specification] [trim_character] FROM] string_primary)</code></div> |
| * |
| * <div><b>BNF:</b> <code>trim_character ::= string_literal | input_parameter</code></div> |
| * <br> |
| * JPA 2.1: |
| * <div><b>BNF:</b> <code>expression ::= TRIM([[trim_specification] [trim_character] FROM] string_expression)</code></div> |
| * |
| * <div><b>BNF:</b> <code>trim_character ::= string_literal | input_parameter</code></div> |
| * |
| * <div>Example: <code><b>UPDATE</b> Student st <b>SET</b> st.sname=TRIM(st.sname)</code></div> |
| * |
| * @version 2.5 |
| * @since 2.3 |
| * @author Pascal Filion |
| */ |
| public final class TrimExpression extends AbstractSingleEncapsulatedExpression { |
| |
| /** |
| * The actual <b>FROM</b> identifier found in the string representation of the JPQL query. |
| */ |
| private String fromIdentifier; |
| |
| /** |
| * Determines whether the identifier <b>FROM</b> was part of the query. |
| */ |
| private boolean hasFrom; |
| |
| /** |
| * Determines whether a space was parsed after the identifier <b>FROM</b>. |
| */ |
| private boolean hasSpaceAfterFrom; |
| |
| /** |
| * Determines whether a space was parsed after the trim specification. |
| */ |
| private boolean hasSpaceAfterSpecification; |
| |
| /** |
| * Determines whether a space was parsed after the trim character. |
| */ |
| private boolean hasSpaceAfterTrimCharacter; |
| |
| /** |
| * The specification specifies how to trim the string. |
| */ |
| private Specification specification; |
| |
| /** |
| * The actual trim specification identifier found in the string representation of the JPQL query. |
| */ |
| private String specificationIdentifier; |
| |
| /** |
| * The character used for trimming the string. |
| */ |
| private AbstractExpression trimCharacter; |
| |
| /** |
| * Creates a new <code>TrimExpression</code>. |
| * |
| * @param parent The parent of this expression |
| */ |
| public TrimExpression(AbstractExpression parent) { |
| super(parent, TRIM); |
| } |
| |
| @Override |
| public void accept(ExpressionVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| public void acceptChildren(ExpressionVisitor visitor) { |
| getTrimCharacter().accept(visitor); |
| super.acceptChildren(visitor); |
| } |
| |
| @Override |
| protected void addOrderedEncapsulatedExpressionTo(List<Expression> children) { |
| |
| // Trim specification |
| if (hasSpecification()) { |
| children.add(buildStringExpression(specification.name())); |
| } |
| |
| if (hasSpaceAfterSpecification) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // Trim character |
| if (hasTrimCharacter()) { |
| children.add(trimCharacter); |
| } |
| |
| if (hasSpaceAfterTrimCharacter) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // 'FROM' |
| if (hasFrom) { |
| children.add(buildStringExpression(FROM)); |
| } |
| |
| if (hasSpaceAfterFrom) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // String primary |
| super.addOrderedEncapsulatedExpressionTo(children); |
| } |
| |
| @Override |
| public String getEncapsulatedExpressionQueryBNFId() { |
| return StringPrimaryBNF.ID; |
| } |
| |
| /** |
| * Returns the actual <b>FROM</b> identifier found in the string representation of the JPQL |
| * query, which has the actual case that was used. |
| * |
| * @return The <b>FROM</b> identifier that was actually parsed, or an empty string if it was not |
| * parsed |
| */ |
| public String getActualFromIdentifier() { |
| return (fromIdentifier != null) ? fromIdentifier : ExpressionTools.EMPTY_STRING; |
| } |
| |
| /** |
| * Returns the actual specification identifier found in the string representation of the JPQL |
| * query, which has the actual case that was used. |
| * |
| * @return The specification identifier that was actually parsed, or an empty string if it was |
| * not parsed |
| */ |
| public String getActualSpecificationIdentifier() { |
| return (specificationIdentifier != null) ? specificationIdentifier : ExpressionTools.EMPTY_STRING; |
| } |
| |
| @Override |
| public JPQLQueryBNF getQueryBNF() { |
| return getQueryBNF(FunctionsReturningStringsBNF.ID); |
| } |
| |
| /** |
| * Returns the specification which specifies how to trim the string. |
| * |
| * @return One of the available choices for trimming the string |
| */ |
| public Specification getSpecification() { |
| return specification; |
| } |
| |
| /** |
| * Returns the character used for trimming the string. |
| * |
| * @return The character, if one was parsed, that will be used to trim the string. If the |
| * character was not specified, then '\0' is the character |
| */ |
| public Expression getTrimCharacter() { |
| if (trimCharacter == null) { |
| trimCharacter = buildNullExpression(); |
| } |
| return trimCharacter; |
| } |
| |
| @Override |
| public boolean hasEncapsulatedExpression() { |
| return hasSpecification() || hasTrimCharacter() || hasFrom || hasExpression(); |
| } |
| |
| /** |
| * Determines whether the identifier <b>FROM</b> was part of the query. |
| * |
| * @return <code>true</code> if the identifier <b>FROM</b> was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasFrom() { |
| return hasFrom; |
| } |
| |
| /** |
| * Determines whether a whitespace was found after <b>FROM</b>. |
| * |
| * @return <code>true</code> if there was a whitespace after <b>FROM</b>; <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterFrom() { |
| return hasSpaceAfterFrom; |
| } |
| |
| /** |
| * Determines whether a whitespace was found after the way the string is trimmed. |
| * |
| * @return <code>true</code> if there was a whitespace after the trim specification; |
| * <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterSpecification() { |
| return hasSpaceAfterSpecification; |
| } |
| |
| /** |
| * Determines whether a whitespace was found after the character used to trim the string. |
| * |
| * @return <code>true</code> if there was a whitespace after the trim character; |
| * <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterTrimCharacter() { |
| return hasSpaceAfterTrimCharacter; |
| } |
| |
| /** |
| * Determines whether the way the trim is trimmed was parsed. |
| * |
| * @return <code>true</code> if the query contained the way the trim needs to |
| * be trimmed; <code>false</code> otherwise |
| */ |
| public boolean hasSpecification() { |
| return (specification != Specification.DEFAULT); |
| } |
| |
| /** |
| * Determines whether the character used to trim the string was specified. |
| * |
| * @return <code>true</code> if the character used for trimming was specified; <code>false</code> |
| * otherwise |
| */ |
| public boolean hasTrimCharacter() { |
| return trimCharacter != null && |
| !trimCharacter.isNull(); |
| } |
| |
| @Override |
| protected void parseEncapsulatedExpression(WordParser wordParser, |
| int whitespaceCount, |
| boolean tolerant) { |
| |
| // Parse the trim specification |
| specification = parseTrimSpecification(wordParser); |
| |
| if (specification != Specification.DEFAULT) { |
| specificationIdentifier = wordParser.moveForward(specification.name().length()); |
| hasSpaceAfterSpecification = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Parse the trim character |
| if (!wordParser.startsWithIdentifier(FROM)) { |
| // Make sure to parse with the encapsulated expression because if it is not |
| // the trim character but the string primary, then it has to be parsed correctly |
| trimCharacter = parse(wordParser, getEncapsulatedExpressionQueryBNFId(), tolerant); |
| } |
| |
| if (hasTrimCharacter()) { |
| hasSpaceAfterTrimCharacter = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Parse 'FROM' |
| hasFrom = wordParser.startsWithIdentifier(FROM); |
| |
| if (hasFrom) { |
| fromIdentifier = wordParser.moveForward(FROM); |
| hasSpaceAfterFrom = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Parse the string primary |
| super.parseEncapsulatedExpression(wordParser, whitespaceCount, tolerant); |
| |
| // The trim character is actually the string primary |
| if (!hasFrom && |
| !hasExpression() && |
| hasTrimCharacter()) { |
| |
| setExpression(trimCharacter); |
| trimCharacter = null; |
| |
| if (hasSpaceAfterTrimCharacter) { |
| hasSpaceAfterTrimCharacter = false; |
| wordParser.moveBackward(1); |
| } |
| } |
| } |
| |
| private Specification parseTrimSpecification(WordParser wordParser) { |
| |
| if (wordParser.startsWithIdentifier(BOTH)) { |
| return Specification.BOTH; |
| } |
| |
| if (wordParser.startsWithIdentifier(LEADING)) { |
| return Specification.LEADING; |
| } |
| |
| if (wordParser.startsWithIdentifier(TRAILING)) { |
| return Specification.TRAILING; |
| } |
| |
| return Specification.DEFAULT; |
| } |
| |
| @Override |
| protected void toParsedTextEncapsulatedExpression(StringBuilder writer, boolean actual) { |
| |
| // Trim specification |
| if (hasSpecification()) { |
| writer.append(specification); |
| } |
| |
| if (hasSpaceAfterSpecification) { |
| writer.append(SPACE); |
| } |
| |
| // Trim character |
| if (hasTrimCharacter()) { |
| trimCharacter.toParsedText(writer, actual); |
| } |
| |
| if (hasSpaceAfterTrimCharacter) { |
| writer.append(SPACE); |
| } |
| |
| // 'FROM' |
| if (hasFrom) { |
| writer.append(actual ? fromIdentifier : FROM); |
| } |
| |
| if (hasSpaceAfterFrom) { |
| writer.append(SPACE); |
| } |
| |
| // String primary |
| super.toParsedTextEncapsulatedExpression(writer, actual); |
| } |
| |
| /** |
| * The possible ways to trim the string. |
| */ |
| public enum Specification { |
| |
| /** |
| * The leading and trailing parts of the string will be trimmed. |
| */ |
| BOTH(Expression.BOTH), |
| |
| /** |
| * Used when the trim specification is not specified, by default it means the leading and |
| * trailing parts of the string will be trimmed. |
| */ |
| DEFAULT(ExpressionTools.EMPTY_STRING), |
| |
| /** |
| * Only the leading part of the string will be trimmed. |
| */ |
| LEADING(Expression.LEADING), |
| |
| /** |
| * Only the trailing part of the string will be trimmed. |
| */ |
| TRAILING(Expression.TRAILING); |
| |
| /** |
| * The actual constant associated with the constant. |
| */ |
| private String value; |
| |
| private Specification(String value) { |
| this.value = value; |
| } |
| |
| /** |
| * Returns the actual identifier associated with the constant. |
| * |
| * @return The identifier associated with the constant or an empty string for {@link #DEFAULT} |
| */ |
| public String getValue() { |
| return value; |
| } |
| } |
| } |