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17 package org.apache.commons.jelly.avalon;
18
19 import java.util.Map;
20 import java.util.HashMap;
21 import java.util.Iterator;
22 import java.net.URL;
23 import java.net.MalformedURLException;
24 import java.io.File;
25 import java.io.InputStream;
26 import java.io.OutputStream;
27
28
29 import org.apache.avalon.framework.configuration.Configurable;
30 import org.apache.avalon.framework.configuration.Configuration;
31 import org.apache.avalon.framework.configuration.ConfigurationException;
32
33
34 import org.apache.commons.jelly.Jelly;
35 import org.apache.commons.jelly.JellyContext;
36 import org.apache.commons.jelly.JellyException;
37 import org.apache.commons.jelly.Script;
38 import org.apache.commons.jelly.XMLOutput;
39
40 /***
41 * An Avalon based service for executing Jelly scripts. The
42 * service allows executing a script based on a name as well
43 * as by a URL.
44 *
45 * @author <a href="mailto:robert@bull-enterprises.com">Robert McIntosh</a>
46 * @version $Revision: 1.4 $
47 */
48 public class JellyServiceImpl implements JellyService, Configurable {
49
50 private boolean m_configured = false;
51 private Map m_scripts = new HashMap();
52
53 /***
54 * Constructor for JellyService.
55 */
56 public JellyServiceImpl() {
57 super();
58 }
59
60 /***
61 * @see org.apache.commons.jelly.avalon.JellyService.runNamedScript(String, Map)
62 */
63 public Map runNamedScript( String name, Map params ) throws Exception {
64 return runNamedScript(name, params, createXMLOutput());
65 }
66
67 /***
68 * @see org.apache.commons.jelly.avalon.JellyService.runNamedScript(String, Map, XMLOutput)
69 */
70 public Map runNamedScript( String name, Map params, XMLOutput output ) throws Exception {
71 if( !m_scripts.containsKey( name ) )
72 throw new JellyException( "No script exists for script name [" + name + "]" );
73
74 Script script = (Script)m_scripts.get( name );
75 JellyContext context = createJellyContext();
76
77 context.setVariables( params );
78
79 script.run( context, output );
80 return context.getVariables();
81 }
82
83 /***
84 * @see org.apache.commons.jelly.avalon.JellyService.runNamedScript(String, Map, OutputStream)
85 */
86 public Map runNamedScript( String name, Map params, OutputStream out ) throws Exception {
87 XMLOutput xmlOutput = XMLOutput.createXMLOutput( out );
88 Map answer = runNamedScript(name, params, xmlOutput);
89 xmlOutput.flush();
90 return answer;
91 }
92
93 /***
94 * @see org.apache.commons.jelly.avalon.JellyService.runScript(String, Map, XMLOutput)
95 */
96 public Map runScript( String url, Map params, XMLOutput output ) throws Exception {
97 URL actualUrl = null;
98 try {
99 actualUrl = new URL( url );
100 }
101 catch( MalformedURLException x ) {
102 throw new JellyException( "Could not find script at URL [" + url + "]: " +
103 x.getMessage(), x );
104 }
105
106
107 JellyContext context = createJellyContext();
108 context.setVariables( params );
109
110
111 context.runScript(url, output);
112 return context.getVariables();
113 }
114
115 /***
116 * @see org.apache.commons.jelly.avalon.JellyService.runScript(String, Map, OutputStream)
117 */
118 public Map runScript( String url, Map params, OutputStream out ) throws Exception {
119 XMLOutput xmlOutput = XMLOutput.createXMLOutput( out );
120 Map answer = runScript(url, params, xmlOutput);
121 xmlOutput.flush();
122 return answer;
123 }
124
125 /***
126 * @see org.apache.commons.jelly.avalon.JellyService.runScript(String, Map)
127 */
128 public Map runScript( String url, Map params ) throws Exception {
129 return runScript(url, params, createXMLOutput());
130 }
131
132
133
134
135
136
137 /***
138 * <p>Configures the Jelly Service with named scripts.</p>
139 *
140 * <p>
141 * The configuration looks like:
142 * </p>
143 * <p>
144 * <jelly><br />
145 * <script><br />
146 * <name>script name</name><br />
147 * <url validate="false">url to script file</url><br />
148 * </script><br />
149 * </jelly><br />
150 * </p>
151 * <p>
152 * Where each <script> element defines a seperate script. The validate attribute
153 * on the url tag is optional and defaults to false.
154 * </p>
155 *
156 * @param config The configuration
157 * @exception ConfigurationException
158 */
159 public void configure( Configuration config ) throws ConfigurationException {
160 if( m_configured )
161 throw new ConfigurationException( "configure may only be executed once" );
162
163 if( !"jelly".equals( config.getName() ) )
164 throw new ConfigurationException( "Expected <jelly> but got " + config.getName() );
165
166
167 Configuration[] scripts = config.getChildren( "scripts" );
168 for (int i = 0; i < scripts.length; i++) {
169 String name = config.getChild( "name" ).getValue();
170
171
172 try {
173 String scriptName = config.getChild( "url" ).getValue();
174
175 URL url = null;
176 File file = new File( scriptName );
177 if( file.exists() ) {
178 url = file.toURL();
179 }
180 else {
181 try {
182 url = new URL( scriptName );
183 }
184 catch( MalformedURLException mfue ) {
185
186 url = getClass().getResource( scriptName );
187 }
188 }
189
190
191 if( url == null )
192 throw new ConfigurationException( "Could not find script [" + scriptName + "]" );
193
194
195 Jelly jelly = new Jelly();
196 jelly.setUrl( url );
197 boolean validate = config.getChild( "url" ).getAttributeAsBoolean( "validate", false );
198 jelly.setValidateXML( validate );
199 Script script = jelly.compileScript();
200
201 m_scripts.put( name, script );
202 }
203 catch( Throwable t ) {
204 throw new ConfigurationException( "Could not load script [" + name + "]: " + t.getMessage() );
205 }
206 }
207 }
208
209
210
211
212
213 /***
214 * Factory method to create a new JellyContext instance. Derived classes
215 * could overload this method to provide a custom JellyContext instance.
216 */
217 protected JellyContext createJellyContext() {
218 return new JellyContext();
219 }
220
221 /***
222 * Factory method to create a new XMLOutput to give to scripts as they run.
223 * Derived classes could overload this method, such as to pipe output to
224 * some log file etc.
225 */
226 protected XMLOutput createXMLOutput() {
227
228 return new XMLOutput();
229 }
230
231 }
232