ExpressionDecideRule - evaluate groovy template with variable "curi" bound

2026-09-15 02:06:03 +00:00 · 2014-03-16 18:13:12 -07:00
parent a36acbacac
commit fb2be86e43
1 changed files with 77 additions and 0 deletions
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+/*
+ *  This file is part of the Heritrix web crawler (crawler.archive.org).
+ *
+ *  Licensed to the Internet Archive (IA) by one or more individual 
+ *  contributors. 
+ *
+ *  The IA licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.archive.modules.deciderules;
+
+import groovy.text.SimpleTemplateEngine;
+import groovy.text.Template;
+
+import java.util.HashMap;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import org.archive.modules.CrawlURI;
+
+/**
+ * Example usage:
+ * <pre> &lt;bean class="org.archive.modules.deciderules.ExpressionDecideRule">
+ *     &lt;property name="groovyExpression" value='${curi.via == null &amp;&amp; curi ==~ "^https?://(?:www\\.)?(facebook|vimeo|flickr)\\.com/.*"}'/>
+ * &lt/bean></pre>
+ *
+ * @contributor nlevitt
+ */
+public class ExpressionDecideRule extends PredicatedDecideRule {
+	private static final long serialVersionUID = 1L;
+	
+	private static final Logger logger =
+            Logger.getLogger(ExpressionDecideRule.class.getName());
+
+    {
+        setGroovyExpression("");
+    }
+    public void setGroovyExpression(String groovyExpression) {
+        kp.put("groovyExpression", groovyExpression);
+    }
+    public String getGroovyExpression() {
+        return (String) kp.get("groovyExpression");
+    }
+
+	protected ConcurrentHashMap<String,Template> groovyTemplates = new ConcurrentHashMap<String, Template>();
+	protected Template groovyTemplate() {
+		Template groovyTemplate = groovyTemplates.get(getGroovyExpression());
+
+		if (groovyTemplate == null) {
+			try {
+				groovyTemplate = new SimpleTemplateEngine().createTemplate(getGroovyExpression());
+				groovyTemplates.put(getGroovyExpression(), groovyTemplate);
+			} catch (Exception e) {
+				logger.log(Level.SEVERE, "problem with groovy expression " + getGroovyExpression(), e);
+			}
+		}
+
+		return groovyTemplate;
+	}
+	
+	@Override
+	protected boolean evaluate(CrawlURI curi) {
+        HashMap<String, Object> binding = new HashMap<String, Object>();
+        binding.put("curi", curi);
+		return String.valueOf(true).equals(groovyTemplate().make(binding).toString());
+	}
+}