001 /*
002 $Id: Script.java 4262 2006-11-25 13:27:06Z blackdrag $
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 groovy.lang;
047
048 import org.codehaus.groovy.ast.expr.ArgumentListExpression;
049 import org.codehaus.groovy.control.CompilationFailedException;
050 import org.codehaus.groovy.runtime.DefaultGroovyMethods;
051 import org.codehaus.groovy.runtime.InvokerHelper;
052
053 import java.io.File;
054 import java.io.IOException;
055
056 /**
057 * This object represents a Groovy script
058 *
059 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
060 * @author Guillaume Laforge
061 * @version $Revision: 4262 $
062 */
063 public abstract class Script extends GroovyObjectSupport {
064 private Binding binding = new Binding();
065
066 protected Script() {
067 }
068
069 protected Script(Binding binding) {
070 this.binding = binding;
071 }
072
073 public Binding getBinding() {
074 return binding;
075 }
076
077 public void setBinding(Binding binding) {
078 this.binding = binding;
079 }
080
081 public Object getProperty(String property) {
082 try {
083 return binding.getVariable(property);
084 } catch (MissingPropertyException e) {
085 return super.getProperty(property);
086 }
087 }
088
089 public void setProperty(String property, Object newValue) {
090 if ("binding".equals(property))
091 setBinding((Binding) newValue);
092 else
093 binding.setVariable(property, newValue);
094 }
095
096 /**
097 * Invoke a method (or closure in the binding) defined.
098 *
099 * @param name method to call
100 * @param args arguments to pass to the method
101 * @return value
102 */
103 public Object invokeMethod(String name, Object args) {
104 try {
105 return super.invokeMethod(name, args);
106 }
107 // if the method was not found in the current scope (the script's methods)
108 // let's try to see if there's a method closure with the same name in the binding
109 catch (MissingMethodException mme) {
110 try {
111 if (name.equals(mme.getMethod())) {
112 Object boundClosure = binding.getVariable(name);
113 if (boundClosure != null && boundClosure instanceof Closure) {
114 return ((Closure) boundClosure).call((Object[])args);
115 } else {
116 throw mme;
117 }
118 } else {
119 throw mme;
120 }
121 } catch (MissingPropertyException mpe) {
122 throw mme;
123 }
124 }
125 }
126
127 /**
128 * The main instance method of a script which has variables in scope
129 * as defined by the current {@link Binding} instance.
130 */
131 public abstract Object run();
132
133 // println helper methods
134
135 /**
136 * Prints a newline to the current 'out' variable which should be a PrintWriter
137 * or at least have a println() method defined on it.
138 * If there is no 'out' property then print to standard out.
139 */
140 public void println() {
141 Object object;
142
143 try {
144 object = getProperty("out");
145 } catch (MissingPropertyException e) {
146 System.out.println();
147 return;
148 }
149
150 InvokerHelper.invokeMethod(object, "println", ArgumentListExpression.EMPTY_ARRAY);
151 }
152
153 /**
154 * Prints the value to the current 'out' variable which should be a PrintWriter
155 * or at least have a print() method defined on it.
156 * If there is no 'out' property then print to standard out.
157 */
158 public void print(Object value) {
159 Object object;
160
161 try {
162 object = getProperty("out");
163 } catch (MissingPropertyException e) {
164 DefaultGroovyMethods.print(System.out,value);
165 return;
166 }
167
168 InvokerHelper.invokeMethod(object, "print", new Object[]{value});
169 }
170
171 /**
172 * Prints the value and a newline to the current 'out' variable which should be a PrintWriter
173 * or at least have a println() method defined on it.
174 * If there is no 'out' property then print to standard out.
175 */
176 public void println(Object value) {
177 Object object;
178
179 try {
180 object = getProperty("out");
181 } catch (MissingPropertyException e) {
182 DefaultGroovyMethods.println(System.out,value);
183 return;
184 }
185
186 InvokerHelper.invokeMethod(object, "println", new Object[]{value});
187 }
188
189 /**
190 * A helper method to allow the dynamic evaluation of groovy expressions using this
191 * scripts binding as the variable scope
192 *
193 * @param expression is the Groovy script expression to evaluate
194 */
195 public Object evaluate(String expression) throws CompilationFailedException, IOException {
196 GroovyShell shell = new GroovyShell(binding);
197 return shell.evaluate(expression);
198 }
199
200 /**
201 * A helper method to allow the dynamic evaluation of groovy expressions using this
202 * scripts binding as the variable scope
203 *
204 * @param file is the Groovy script to evaluate
205 */
206 public Object evaluate(File file) throws CompilationFailedException, IOException {
207 GroovyShell shell = new GroovyShell(binding);
208 return shell.evaluate(file);
209 }
210
211 /**
212 * A helper method to allow scripts to be run taking command line arguments
213 */
214 public void run(File file, String[] arguments) throws CompilationFailedException, IOException {
215 GroovyShell shell = new GroovyShell(binding);
216 shell.run(file, arguments);
217 }
218 }