| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.olingo.server.core.uri.parser; |
| |
| import org.apache.olingo.server.api.uri.queryoption.SearchOption; |
| import org.apache.olingo.server.api.uri.queryoption.search.SearchBinaryOperatorKind; |
| import org.apache.olingo.server.api.uri.queryoption.search.SearchExpression; |
| import org.apache.olingo.server.api.uri.queryoption.search.SearchTerm; |
| import org.apache.olingo.server.core.uri.parser.UriTokenizer.TokenKind; |
| import org.apache.olingo.server.core.uri.parser.search.SearchBinaryImpl; |
| import org.apache.olingo.server.core.uri.parser.search.SearchParserException; |
| import org.apache.olingo.server.core.uri.parser.search.SearchTermImpl; |
| import org.apache.olingo.server.core.uri.parser.search.SearchUnaryImpl; |
| import org.apache.olingo.server.core.uri.queryoption.SearchOptionImpl; |
| |
| /** |
| * Parses search expressions according to the following (rewritten) grammar: |
| * <pre> |
| * SearchExpr ::= ExprOR |
| * ExprOR ::= ExprAnd ('OR' ExprAnd)* |
| * ExprAnd ::= Term ('AND'? Term)* |
| * Term ::= ('NOT'? (Word | Phrase)) | ('(' SearchExpr ')') |
| * </pre> |
| */ |
| public class SearchParser { |
| |
| public SearchOption parse(UriTokenizer tokenizer) throws SearchParserException { |
| SearchOptionImpl searchOption = new SearchOptionImpl(); |
| searchOption.setSearchExpression(processExprOr(tokenizer)); |
| return searchOption; |
| } |
| |
| private SearchExpression processExprOr(UriTokenizer tokenizer) throws SearchParserException { |
| SearchExpression left = processExprAnd(tokenizer); |
| |
| while (tokenizer.next(TokenKind.OrOperatorSearch)) { |
| final SearchExpression right = processExprAnd(tokenizer); |
| left = new SearchBinaryImpl(left, SearchBinaryOperatorKind.OR, right); |
| } |
| |
| return left; |
| } |
| |
| private SearchExpression processExprAnd(UriTokenizer tokenizer) throws SearchParserException { |
| SearchExpression left = processTerm(tokenizer); |
| |
| while (tokenizer.next(TokenKind.AndOperatorSearch)) { |
| // Could be whitespace or whitespace-surrounded 'AND'. |
| final SearchExpression right = processTerm(tokenizer); |
| left = new SearchBinaryImpl(left, SearchBinaryOperatorKind.AND, right); |
| } |
| |
| return left; |
| } |
| |
| private SearchExpression processTerm(UriTokenizer tokenizer) throws SearchParserException { |
| if (tokenizer.next(TokenKind.OPEN)) { |
| final SearchExpression expr = processExprOr(tokenizer); |
| if (!tokenizer.next(TokenKind.CLOSE)) { |
| throw new SearchParserException("Missing close parenthesis after open parenthesis.", |
| SearchParserException.MessageKeys.MISSING_CLOSE); |
| } |
| return expr; |
| } else if (tokenizer.next(TokenKind.NotOperatorSearch)) { |
| return processNot(tokenizer); |
| } else if (tokenizer.next(TokenKind.Word)) { |
| return new SearchTermImpl(tokenizer.getText()); |
| } else if (tokenizer.next(TokenKind.Phrase)) { |
| return processPhrase(tokenizer); |
| } else { |
| throw new SearchParserException("Expected PHRASE or WORD not found.", |
| SearchParserException.MessageKeys.EXPECTED_DIFFERENT_TOKEN, "PHRASE, WORD", ""); |
| } |
| } |
| |
| private SearchExpression processNot(UriTokenizer tokenizer) throws SearchParserException { |
| if (tokenizer.next(TokenKind.Word)) { |
| return new SearchUnaryImpl(new SearchTermImpl(tokenizer.getText())); |
| } else if (tokenizer.next(TokenKind.Phrase)) { |
| return new SearchUnaryImpl(processPhrase(tokenizer)); |
| } else { |
| throw new SearchParserException("NOT must be followed by a term.", |
| SearchParserException.MessageKeys.INVALID_NOT_OPERAND, ""); |
| } |
| } |
| |
| private SearchTerm processPhrase(UriTokenizer tokenizer) { |
| final String literal = tokenizer.getText(); |
| return new SearchTermImpl(literal.substring(1, literal.length() - 1) |
| .replace("\\\"", "\"") |
| .replace("\\\\", "\\")); |
| } |
| } |