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 java.util.List; 020import java.util.concurrent.CopyOnWriteArrayList; 021 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.ObjectHelper; 026 027/** 028 * Tokenizer to create {@link SimpleToken} from the input. 029 */ 030public final class SimpleTokenizer { 031 032 // use CopyOnWriteArrayList so we can modify it in the for loop when changing function start/end tokens 033 private static final List<SimpleTokenType> KNOWN_TOKENS = new CopyOnWriteArrayList<SimpleTokenType>(); 034 035 static { 036 // add known tokens 037 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.whiteSpace, " ")); 038 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.whiteSpace, "\t")); 039 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.whiteSpace, "\n")); 040 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.whiteSpace, "\r")); 041 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.singleQuote, "'")); 042 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.doubleQuote, "\"")); 043 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.functionStart, "${")); 044 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.functionStart, "$simple{")); 045 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.functionEnd, "}")); 046 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.booleanValue, "true")); 047 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.booleanValue, "false")); 048 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.nullValue, "null")); 049 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.escape, "\\")); 050 051 // binary operators 052 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "==")); 053 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "=~")); 054 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, ">=")); 055 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "<=")); 056 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, ">")); 057 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "<")); 058 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "!=")); 059 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "not is")); 060 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "is")); 061 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "not contains")); 062 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "contains")); 063 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "not regex")); 064 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "regex")); 065 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "not in")); 066 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "in")); 067 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "range")); 068 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "not range")); 069 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.binaryOperator, "ends with")); 070 071 // unary operators 072 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.unaryOperator, "++")); 073 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.unaryOperator, "--")); 074 075 // logical operators 076 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.logicalOperator, "&&")); 077 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.logicalOperator, "||")); 078 // TODO: @deprecated logical operators, to be removed in Camel 3.0 079 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.logicalOperator, "and")); 080 KNOWN_TOKENS.add(new SimpleTokenType(TokenType.logicalOperator, "or")); 081 } 082 083 private SimpleTokenizer() { 084 // static methods 085 } 086 087 088 /** 089 * @see SimpleLanguage#changeFunctionStartToken(String...) 090 */ 091 public static void changeFunctionStartToken(String... startToken) { 092 for (SimpleTokenType type : KNOWN_TOKENS) { 093 if (type.getType() == TokenType.functionStart) { 094 KNOWN_TOKENS.remove(type); 095 } 096 } 097 098 // add in start of list as its a more common token to be used 099 for (String token : startToken) { 100 KNOWN_TOKENS.add(0, new SimpleTokenType(TokenType.functionStart, token)); 101 } 102 } 103 104 /** 105 * @see SimpleLanguage#changeFunctionEndToken(String...) 106 */ 107 public static void changeFunctionEndToken(String... endToken) { 108 for (SimpleTokenType type : KNOWN_TOKENS) { 109 if (type.getType() == TokenType.functionEnd) { 110 KNOWN_TOKENS.remove(type); 111 } 112 } 113 114 // add in start of list as its a more common token to be used 115 for (String token : endToken) { 116 KNOWN_TOKENS.add(0, new SimpleTokenType(TokenType.functionEnd, token)); 117 } 118 } 119 120 /** 121 * Create the next token 122 * 123 * @param expression the input expression 124 * @param index the current index 125 * @param allowEscape whether to allow escapes 126 * @param filter defines the accepted token types to be returned (character is always used as fallback) 127 * @return the created token, will always return a token 128 */ 129 public static SimpleToken nextToken(String expression, int index, boolean allowEscape, TokenType... filter) { 130 return doNextToken(expression, index, allowEscape, filter); 131 } 132 133 /** 134 * Create the next token 135 * 136 * @param expression the input expression 137 * @param index the current index 138 * @param allowEscape whether to allow escapes 139 * @return the created token, will always return a token 140 */ 141 public static SimpleToken nextToken(String expression, int index, boolean allowEscape) { 142 return doNextToken(expression, index, allowEscape); 143 } 144 145 private static SimpleToken doNextToken(String expression, int index, boolean allowEscape, TokenType... filters) { 146 147 boolean numericAllowed = acceptType(TokenType.numericValue, filters); 148 if (numericAllowed) { 149 // is it a numeric value 150 StringBuilder sb = new StringBuilder(); 151 boolean digit = true; 152 while (digit && index < expression.length()) { 153 digit = Character.isDigit(expression.charAt(index)); 154 if (digit) { 155 char ch = expression.charAt(index); 156 sb.append(ch); 157 index++; 158 continue; 159 } 160 // is it a dot or comma as part of a floating point number 161 boolean decimalSeparator = '.' == expression.charAt(index) || ',' == expression.charAt(index); 162 if (decimalSeparator && sb.length() > 0) { 163 char ch = expression.charAt(index); 164 sb.append(ch); 165 index++; 166 // assume its still a digit 167 digit = true; 168 continue; 169 } 170 } 171 if (sb.length() > 0) { 172 return new SimpleToken(new SimpleTokenType(TokenType.numericValue, sb.toString()), index); 173 } 174 } 175 176 boolean escapeAllowed = allowEscape && acceptType(TokenType.escape, filters); 177 if (escapeAllowed) { 178 StringBuilder sb = new StringBuilder(); 179 char ch = expression.charAt(index); 180 boolean escaped = '\\' == ch; 181 if (escaped && index < expression.length() - 1) { 182 // grab next character to escape 183 char next = expression.charAt(++index); 184 // special for new line, tabs and carriage return 185 boolean special = false; 186 if ('n' == next) { 187 sb.append("\n"); 188 special = true; 189 } else if ('t' == next) { 190 sb.append("\t"); 191 special = true; 192 } else if ('r' == next) { 193 sb.append("\r"); 194 special = true; 195 } else { 196 // not special just a regular character 197 sb.append(ch); 198 } 199 200 // force 2 as length if special 201 return new SimpleToken(new SimpleTokenType(TokenType.character, sb.toString()), index, special ? 2 : 1); 202 } 203 } 204 205 // it could be any of the known tokens 206 String text = expression.substring(index); 207 for (SimpleTokenType token : KNOWN_TOKENS) { 208 if (acceptType(token.getType(), filters)) { 209 if (acceptToken(token, text, expression, index)) { 210 return new SimpleToken(token, index); 211 } 212 } 213 } 214 215 // fallback and create a character token 216 char ch = expression.charAt(index); 217 SimpleToken token = new SimpleToken(new SimpleTokenType(TokenType.character, "" + ch), index); 218 return token; 219 } 220 221 private static boolean acceptType(TokenType type, TokenType... filters) { 222 if (filters == null || filters.length == 0) { 223 return true; 224 } 225 for (TokenType filter : filters) { 226 if (type == filter) { 227 return true; 228 } 229 } 230 return false; 231 } 232 233 private static boolean acceptToken(SimpleTokenType token, String text, String expression, int index) { 234 if (token.isUnary() && text.startsWith(token.getValue())) { 235 SimpleTokenType functionEndToken = getFunctionEndToken(); 236 if (functionEndToken != null) { 237 int endLen = functionEndToken.getValue().length(); 238 239 // special check for unary as the previous must be a function end, and the next a whitespace 240 // to ensure unary operators is only applied on functions as intended 241 int len = token.getValue().length(); 242 243 String previous = ""; 244 if (index - endLen >= 0) { 245 previous = expression.substring(index - endLen, index); 246 } 247 String after = text.substring(len); 248 boolean whiteSpace = ObjectHelper.isEmpty(after) || after.startsWith(" "); 249 boolean functionEnd = previous.equals(functionEndToken.getValue()); 250 return functionEnd && whiteSpace; 251 } 252 } 253 254 return text.startsWith(token.getValue()); 255 } 256 257 private static SimpleTokenType getFunctionEndToken() { 258 for (SimpleTokenType token : KNOWN_TOKENS) { 259 if (token.isFunctionEnd()) { 260 return token; 261 } 262 } 263 return null; 264 } 265 266}