001/** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.camel.language.simple; 018 019import org.apache.camel.Expression; 020import org.apache.camel.Predicate; 021import org.apache.camel.language.simple.ast.SimpleFunctionExpression; 022import org.apache.camel.language.simple.types.SimpleToken; 023import org.apache.camel.language.simple.types.SimpleTokenType; 024import org.apache.camel.language.simple.types.TokenType; 025import org.apache.camel.util.ExpressionToPredicateAdapter; 026 027/** 028 * A backwards compatible parser, which supports the old simple language 029 * syntax by which simple functions can be given without using start and 030 * end tokens. 031 * <p/> 032 * For example "body" would be parsed as the body function, where as the 033 * new parser would require that to be entered as "${body}". 034 * <p/> 035 * This parser is to be removed when the old syntax is no longer supported. 036 * 037 * @deprecated will be removed in Camel 3.0 038 */ 039@Deprecated 040public final class SimpleBackwardsCompatibleParser { 041 042 private SimpleBackwardsCompatibleParser() { 043 // static methods 044 } 045 046 public static Expression parseExpression(String expression, boolean allowEscape) { 047 return doParseExpression(expression, allowEscape); 048 } 049 050 public static Predicate parsePredicate(String expression, boolean allowEscape) { 051 Expression answer = doParseExpression(expression, allowEscape); 052 if (answer != null) { 053 return ExpressionToPredicateAdapter.toPredicate(answer); 054 } else { 055 return null; 056 } 057 } 058 059 private static Expression doParseExpression(String expression, boolean allowEscape) { 060 // should have no function tokens 061 for (int i = 0; i < expression.length(); i++) { 062 SimpleToken token = SimpleTokenizer.nextToken(expression, i, allowEscape, TokenType.functionStart, TokenType.functionEnd); 063 if (token.getType().getType() == TokenType.functionStart || token.getType().getType() == TokenType.functionEnd) { 064 return null; 065 } 066 } 067 068 // okay there is no function tokens, then try to parse it as a simple function expression 069 SimpleToken token = new SimpleToken(new SimpleTokenType(TokenType.functionStart, expression), 0); 070 SimpleFunctionExpression function = new SimpleFunctionExpression(token); 071 function.addText(expression); 072 return function.createExpression(expression, false); 073 } 074 075}