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17 package org.apache.commons.scxml.test;
18
19 import java.io.BufferedReader;
20 import java.io.File;
21 import java.io.IOException;
22 import java.io.InputStreamReader;
23 import java.net.URL;
24 import java.util.StringTokenizer;
25
26 import org.apache.commons.scxml.Context;
27 import org.apache.commons.scxml.Evaluator;
28 import org.apache.commons.scxml.EventDispatcher;
29 import org.apache.commons.scxml.SCXMLExecutor;
30 import org.apache.commons.scxml.SCXMLHelper;
31 import org.apache.commons.scxml.TriggerEvent;
32 import org.apache.commons.scxml.env.SimpleScheduler;
33 import org.apache.commons.scxml.env.Tracer;
34 import org.apache.commons.scxml.invoke.SimpleSCXMLInvoker;
35 import org.apache.commons.scxml.io.SCXMLDigester;
36 import org.apache.commons.scxml.io.SCXMLSerializer;
37 import org.apache.commons.scxml.model.ModelException;
38 import org.apache.commons.scxml.model.SCXML;
39 import org.xml.sax.SAXException;
40
41 /***
42 * Utility methods used by command line SCXML execution, useful for
43 * debugging.
44 *
45 * The following expression languages are supported in SCXML documents:
46 * <ol>
47 * <li>JEXL - Using Commons JEXL</li>
48 * <li>EL - Using Commons EL</li>
49 * </ol>
50 *
51 * @see org.apache.commons.scxml.env.jexl
52 * @see org.apache.commons.scxml.env.jsp
53 */
54 public final class StandaloneUtils {
55
56 /***
57 * Command line utility method for executing the state machine defined
58 * using the SCXML document described by the specified URI and using
59 * the specified expression evaluator.
60 *
61 * @param uri The URI or filename of the SCXML document
62 * @param evaluator The expression evaluator for the expression language
63 * used in the specified SCXML document
64 *
65 * <p>RUNNING:</p>
66 * <ul>
67 * <li>Enter a space-separated list of "events"</li>
68 * <li>To quit, enter "quit"</li>
69 * <li>To populate a variable in the current context,
70 * type "name=value"</li>
71 * <li>To reset state machine, enter "reset"</li>
72 * </ul>
73 */
74 public static void execute(final String uri, final Evaluator evaluator) {
75 try {
76 String documentURI = getCanonicalURI(uri);
77 Context rootCtx = evaluator.newContext(null);
78 Tracer trc = new Tracer();
79 SCXML doc = SCXMLDigester.digest(new URL(documentURI), trc);
80 if (doc == null) {
81 System.err.println("The SCXML document " + uri
82 + " can not be parsed!");
83 System.exit(-1);
84 }
85 System.out.println(SCXMLSerializer.serialize(doc));
86 SCXMLExecutor exec = new SCXMLExecutor(evaluator, null, trc);
87 EventDispatcher ed = new SimpleScheduler(exec);
88 exec.setEventdispatcher(ed);
89 exec.setStateMachine(doc);
90 exec.addListener(doc, trc);
91 exec.registerInvokerClass("scxml", SimpleSCXMLInvoker.class);
92 exec.setRootContext(rootCtx);
93 exec.go();
94 BufferedReader br = new BufferedReader(new
95 InputStreamReader(System.in));
96 String event = null;
97 while ((event = br.readLine()) != null) {
98 event = event.trim();
99 if (event.equalsIgnoreCase("help") || event.equals("?")) {
100 System.out.println("Enter a space-separated list of "
101 + "events");
102 System.out.println("To populate a variable in the "
103 + "current context, type \"name=value\"");
104 System.out.println("To quit, enter \"quit\"");
105 System.out.println("To reset state machine, enter "
106 + "\"reset\"");
107 } else if (event.equalsIgnoreCase("quit")) {
108 break;
109 } else if (event.equalsIgnoreCase("reset")) {
110 exec.reset();
111 } else if (event.indexOf('=') != -1) {
112 int marker = event.indexOf('=');
113 String name = event.substring(0, marker);
114 String value = event.substring(marker + 1);
115 rootCtx.setLocal(name, value);
116 System.out.println("Set variable " + name + " to "
117 + value);
118 } else if (SCXMLHelper.isStringEmpty(event)
119 || event.equalsIgnoreCase("null")) {
120 TriggerEvent[] evts = {new TriggerEvent(null,
121 TriggerEvent.SIGNAL_EVENT, null)};
122 exec.triggerEvents(evts);
123 if (exec.getCurrentStatus().isFinal()) {
124 System.out.println("A final configuration reached.");
125 }
126 } else {
127 StringTokenizer st = new StringTokenizer(event);
128 int tkns = st.countTokens();
129 TriggerEvent[] evts = new TriggerEvent[tkns];
130 for (int i = 0; i < tkns; i++) {
131 evts[i] = new TriggerEvent(st.nextToken(),
132 TriggerEvent.SIGNAL_EVENT, null);
133 }
134 exec.triggerEvents(evts);
135 if (exec.getCurrentStatus().isFinal()) {
136 System.out.println("A final configuration reached.");
137 }
138 }
139 }
140 } catch (IOException e) {
141 e.printStackTrace();
142 } catch (ModelException e) {
143 e.printStackTrace();
144 } catch (SAXException e) {
145 e.printStackTrace();
146 }
147 }
148
149 /***
150 * @param uri an absolute or relative URL
151 * @return java.lang.String canonical URL (absolute)
152 * @throws java.io.IOException if a relative URL can not be resolved
153 * to a local file
154 */
155 private static String getCanonicalURI(final String uri)
156 throws IOException {
157 if (uri.toLowerCase().startsWith("http://")
158 || uri.toLowerCase().startsWith("file://")) {
159 return uri;
160 }
161 File in = new File(uri);
162 return "file:///" + in.getCanonicalPath();
163 }
164
165 /***
166 * Discourage instantiation since this is a utility class.
167 */
168 private StandaloneUtils() {
169 super();
170 }
171
172 }
173