001 /*
002 $Id: GroovyEngine.java,v 1.10 2004/12/27 10:31:26 spullara Exp $
003
004 Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
005
006 Redistribution and use of this software and associated documentation
007 ("Software"), with or without modification, are permitted provided
008 that the following conditions are met:
009
010 1. Redistributions of source code must retain copyright
011 statements and notices. Redistributions must also contain a
012 copy of this document.
013
014 2. Redistributions in binary form must reproduce the
015 above copyright notice, this list of conditions and the
016 following disclaimer in the documentation and/or other
017 materials provided with the distribution.
018
019 3. The name "groovy" must not be used to endorse or promote
020 products derived from this Software without prior written
021 permission of The Codehaus. For written permission,
022 please contact info@codehaus.org.
023
024 4. Products derived from this Software may not be called "groovy"
025 nor may "groovy" appear in their names without prior written
026 permission of The Codehaus. "groovy" is a registered
027 trademark of The Codehaus.
028
029 5. Due credit should be given to The Codehaus -
030 http://groovy.codehaus.org/
031
032 THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
033 ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
034 NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
035 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
036 THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
037 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
038 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
039 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
040 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
041 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
042 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
043 OF THE POSSIBILITY OF SUCH DAMAGE.
044
045 */
046 package org.codehaus.groovy.bsf;
047
048 import groovy.lang.Closure;
049 import groovy.lang.GroovyShell;
050 import org.apache.bsf.BSFDeclaredBean;
051 import org.apache.bsf.BSFException;
052 import org.apache.bsf.BSFManager;
053 import org.apache.bsf.util.BSFEngineImpl;
054 import org.apache.bsf.util.BSFFunctions;
055 import org.codehaus.groovy.runtime.InvokerHelper;
056
057 import java.util.Vector;
058
059 /**
060 * A BSF Engine for the <a href="http://groovy.codehaus.org/">Groovy</a>
061 * scripting language.
062 * <p/>
063 * It's derived from the Jython / JPython engine
064 *
065 * @author James Strachan
066 */
067 public class GroovyEngine extends BSFEngineImpl {
068 private static final String[] EMPTY_ARGS = {
069 };
070
071 protected GroovyShell shell;
072
073 /**
074 * Convert a non java class name to a java classname
075 * This is used to convert a script name to a name
076 * that can be used as a classname with the script is
077 * loaded in GroovyClassloader#load()
078 * The method simply replaces any invalid characters
079 * with "_".
080 */
081 private String convertToValidJavaClassname(String inName) {
082 if (inName == null || inName.equals("")) {
083 return "_";
084 }
085 StringBuffer output = new StringBuffer(inName.length());
086 boolean firstChar = true;
087 for (int i = 0; i < inName.length(); ++i) {
088 char ch = inName.charAt(i);
089 if (firstChar && !Character.isJavaIdentifierStart(ch)) {
090 ch = '_';
091 } else if (!firstChar
092 && !(Character.isJavaIdentifierPart(ch) || ch == '.')) {
093 ch = '_';
094 }
095 firstChar = (ch == '.');
096 output.append(ch);
097 }
098 return output.toString();
099 }
100
101 /**
102 * Allow an anonymous function to be declared and invoked
103 */
104 public Object apply(java.lang.String source,
105 int lineNo,
106 int columnNo,
107 Object funcBody,
108 Vector paramNames,
109 Vector arguments)
110 throws BSFException {
111
112 Object object = eval(source, lineNo, columnNo, funcBody);
113 if (object instanceof Closure) {
114 // lets call the function
115
116 /** @todo we could turn the 2 vectors into a Map */
117 Closure closure = (Closure) object;
118 return closure.call(arguments.toArray());
119 }
120 return object;
121 }
122
123 /**
124 * Call the named method of the given object.
125 */
126 public Object call(Object object, String method, Object[] args) throws BSFException {
127 return InvokerHelper.invokeMethod(object, method, args);
128 }
129
130 /**
131 * Declare a bean
132 */
133 public void declareBean(BSFDeclaredBean bean) throws BSFException {
134 //System.out.println("Declaring bean: " + bean.name + " value: " + bean.bean);
135 shell.setVariable(bean.name, bean.bean);
136 }
137
138 /**
139 * Evaluate an expression.
140 */
141 public Object eval(String source, int lineNo, int columnNo, Object script) throws BSFException {
142 try {
143 source = convertToValidJavaClassname(source);
144 Object result = getEvalShell().evaluate(script.toString(), source);
145 return result;
146 } catch (Exception e) {
147 throw new BSFException(BSFException.REASON_EXECUTION_ERROR, "exception from Groovy: " + e, e);
148 }
149 }
150
151 /**
152 * Execute a script.
153 */
154 public void exec(String source, int lineNo, int columnNo, Object script) throws BSFException {
155 try {
156 // use evaluate to pass in the BSF variables
157 source = convertToValidJavaClassname(source);
158 getEvalShell().evaluate(script.toString(), source);
159 //getEvalShell().run(script.toString(), source, EMPTY_ARGS);
160 } catch (Exception e) {
161 throw new BSFException(BSFException.REASON_EXECUTION_ERROR, "exception from Groovy: " + e, e);
162 }
163 }
164
165 /**
166 * Initialize the engine.
167 */
168 public void initialize(BSFManager mgr, String lang, Vector declaredBeans) throws BSFException {
169 super.initialize(mgr, lang, declaredBeans);
170
171 // create a shell
172 shell = new GroovyShell(mgr.getClassLoader());
173
174 // register the mgr with object name "bsf"
175 shell.setVariable("bsf", new BSFFunctions(mgr, this));
176
177 int size = declaredBeans.size();
178 for (int i = 0; i < size; i++) {
179 declareBean((BSFDeclaredBean) declaredBeans.elementAt(i));
180 }
181 }
182
183 /**
184 * Undeclare a previously declared bean.
185 */
186 public void undeclareBean(BSFDeclaredBean bean) throws BSFException {
187 shell.setVariable(bean.name, null);
188 }
189
190 /**
191 * @return a newly created GroovyShell using the same variable scope but a new class loader
192 */
193 protected GroovyShell getEvalShell() {
194 return new GroovyShell(shell);
195 }
196 }