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 */
017 package org.apache.camel.language.simple;
018
019 import org.apache.camel.Expression;
020 import org.apache.camel.ExpressionIllegalSyntaxException;
021 import org.apache.camel.builder.ExpressionBuilder;
022 import org.apache.camel.util.ObjectHelper;
023
024 /**
025 * A <a href="http://camel.apache.org/simple.html">simple language</a>
026 * which maps simple property style notations to access headers and bodies.
027 * Examples of supported expressions are:
028 * <ul>
029 * <li>id to access the inbound message id</li>
030 * <li>in.body or body to access the inbound body</li>
031 * <li>out.body to access the inbound body</li>
032 * <li>in.header.foo or header.foo to access an inbound header called 'foo'</li>
033 * <li>out.header.foo to access an outbound header called 'foo'</li>
034 * <li>property.foo to access the exchange property called 'foo'</li>
035 * <li>sys.foo to access the system property called 'foo'</li>
036 * <li>exception.messsage to access the exception message</li>
037 * <li>date:<command>:<pattern> for date formatting using the {@link java.text.SimpleDateFormat} patterns.
038 * Supported commands are: <tt>now</tt> for current timestamp,
039 * <tt>in.header.xxx</tt> or <tt>header.xxx</tt> to use the Date object in the in header.
040 * <tt>out.header.xxx</tt> to use the Date object in the out header.
041 * </li>
042 * <li>bean:<bean expression> to invoke a bean using the
043 * {@link org.apache.camel.language.bean.BeanLanguage BeanLanguage}</li>
044 * </ul>
045 * <p/>
046 * The simple language now also includes file language out of the box which means the following expression is also
047 * supported:
048 * <ul>
049 * <li><tt>file:name</tt> to access the file name (is relative, see note below))</li>
050 * <li><tt>file:name.noext</tt> to access the file name with no extension</li>
051 * <li><tt>file:ext</tt> to access the file extension</li>
052 * <li><tt>file:onlyname</tt> to access the file name (no paths)</li>
053 * <li><tt>file:onlyname.noext</tt> to access the file name (no paths) with no extension </li>
054 * <li><tt>file:parent</tt> to access the parent file name</li>
055 * <li><tt>file:path</tt> to access the file path name</li>
056 * <li><tt>file:absolute</tt> is the file regarded as absolute or relative</li>
057 * <li><tt>file:absolute.path</tt> to access the absolute file path name</li>
058 * <li><tt>file:length</tt> to access the file length as a Long type</li>
059 * <li><tt>file:modified</tt> to access the file last modified as a Date type</li>
060 * <li><tt>date:<command>:<pattern></tt> for date formatting using the {@link java.text.SimpleDateFormat} patterns.
061 * Additional Supported commands are: <tt>file</tt> for the last modified timestamp of the file.
062 * All the commands from {@link SimpleLanguage} is also available.
063 * </li>
064 * </ul>
065 * The <b>relative</b> file is the filename with the starting directory clipped, as opposed to <b>path</b> that will
066 * return the full path including the starting directory.
067 * <br/>
068 * The <b>only</b> file is the filename only with all paths clipped.
069 *
070 * @version $Revision: 898656 $
071 */
072 public class SimpleLanguage extends SimpleLanguageSupport {
073
074 private static final SimpleLanguage SIMPLE = new SimpleLanguage();
075
076 public static Expression simple(String expression) {
077 return SIMPLE.createExpression(expression);
078 }
079
080 protected Expression createSimpleExpression(String expression, boolean strict) {
081 if (ObjectHelper.isEqualToAny(expression, "body", "in.body")) {
082 return ExpressionBuilder.bodyExpression();
083 } else if (ObjectHelper.equal(expression, "out.body")) {
084 return ExpressionBuilder.outBodyExpression();
085 } else if (ObjectHelper.equal(expression, "id")) {
086 return ExpressionBuilder.messageIdExpression();
087 } else if (ObjectHelper.equal(expression, "exception.message")) {
088 return ExpressionBuilder.exchangeExceptionMessageExpression();
089 }
090
091 // in header expression
092 String remainder = ifStartsWithReturnRemainder("in.header.", expression);
093 if (remainder == null) {
094 remainder = ifStartsWithReturnRemainder("header.", expression);
095 }
096 if (remainder == null) {
097 remainder = ifStartsWithReturnRemainder("headers.", expression);
098 }
099 if (remainder == null) {
100 remainder = ifStartsWithReturnRemainder("in.headers.", expression);
101 }
102 if (remainder != null) {
103 return ExpressionBuilder.headerExpression(remainder);
104 }
105
106 // out header expression
107 remainder = ifStartsWithReturnRemainder("out.header.", expression);
108 if (remainder == null) {
109 remainder = ifStartsWithReturnRemainder("out.headers.", expression);
110 }
111 if (remainder != null) {
112 return ExpressionBuilder.outHeaderExpression(remainder);
113 }
114
115 // property
116 remainder = ifStartsWithReturnRemainder("property.", expression);
117 if (remainder != null) {
118 return ExpressionBuilder.propertyExpression(remainder);
119 }
120
121 // system property
122 remainder = ifStartsWithReturnRemainder("sys.", expression);
123 if (remainder != null) {
124 return ExpressionBuilder.systemPropertyExpression(remainder);
125 }
126
127 // file: prefix
128 remainder = ifStartsWithReturnRemainder("file:", expression);
129 if (remainder != null) {
130 Expression fileExpression = createSimpleFileExpression(remainder);
131 if (expression != null) {
132 return fileExpression;
133 }
134 }
135
136 // date: prefix
137 remainder = ifStartsWithReturnRemainder("date:", expression);
138 if (remainder != null) {
139 String[] parts = remainder.split(":");
140 if (parts.length < 2) {
141 throw new ExpressionIllegalSyntaxException("Valid syntax: ${date:command:pattern} was: " + expression);
142 }
143 String command = ObjectHelper.before(remainder, ":");
144 String pattern = ObjectHelper.after(remainder, ":");
145 return ExpressionBuilder.dateExpression(command, pattern);
146 }
147
148 // bean: prefix
149 remainder = ifStartsWithReturnRemainder("bean:", expression);
150 if (remainder != null) {
151 return ExpressionBuilder.beanExpression(remainder);
152 }
153
154 if (strict) {
155 throw new ExpressionIllegalSyntaxException(expression);
156 } else {
157 return ExpressionBuilder.constantExpression(expression);
158 }
159 }
160
161 public Expression createSimpleFileExpression(String remainder) {
162 if (ObjectHelper.equal(remainder, "name")) {
163 return ExpressionBuilder.fileNameExpression();
164 } else if (ObjectHelper.equal(remainder, "name.noext")) {
165 return ExpressionBuilder.fileNameNoExtensionExpression();
166 } else if (ObjectHelper.equal(remainder, "onlyname")) {
167 return ExpressionBuilder.fileOnlyNameExpression();
168 } else if (ObjectHelper.equal(remainder, "onlyname.noext")) {
169 return ExpressionBuilder.fileOnlyNameNoExtensionExpression();
170 } else if (ObjectHelper.equal(remainder, "ext")) {
171 return ExpressionBuilder.fileExtensionExpression();
172 } else if (ObjectHelper.equal(remainder, "parent")) {
173 return ExpressionBuilder.fileParentExpression();
174 } else if (ObjectHelper.equal(remainder, "path")) {
175 return ExpressionBuilder.filePathExpression();
176 } else if (ObjectHelper.equal(remainder, "absolute")) {
177 return ExpressionBuilder.fileAbsoluteExpression();
178 } else if (ObjectHelper.equal(remainder, "absolute.path")) {
179 return ExpressionBuilder.fileAbsolutePathExpression();
180 } else if (ObjectHelper.equal(remainder, "length")) {
181 return ExpressionBuilder.fileSizeExpression();
182 } else if (ObjectHelper.equal(remainder, "modified")) {
183 return ExpressionBuilder.fileLastModifiedExpression();
184 }
185 return null;
186 }
187
188 public boolean isSingleton() {
189 return true;
190 }
191 }