Create a smoke test to check the connection to Solr.

webapp/src/edu/cornell/mannlib/vitro/webapp/servlet/setup/SolrSmokeTest.java

@@ -0,0 +1,132 @@
+/* $This file is distributed under the terms of the license in /doc/license.txt$ */
+
+package edu.cornell.mannlib.vitro.webapp.servlet.setup;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+
+import javax.servlet.ServletContextEvent;
+import javax.servlet.ServletContextListener;
+
+import org.apache.commons.httpclient.HttpClient;
+import org.apache.commons.httpclient.HttpException;
+import org.apache.commons.httpclient.HttpStatus;
+import org.apache.commons.httpclient.methods.GetMethod;
+
+import edu.cornell.mannlib.vitro.webapp.config.ConfigurationProperties;
+import edu.cornell.mannlib.vitro.webapp.startup.StartupStatus;
+import edu.cornell.mannlib.vitro.webapp.utils.threads.VitroBackgroundThread;
+
+/**
+ * Spin off a thread that will try to connect to Solr.
+ * 
+ * We need to do this in a separate thread because if Solr is in the same Tomcat
+ * instance as Vitro, it may not be initialized until after Vitro is
+ * initialized. Which is to say, after this Listener has run.
+ * 
+ * If we can't connect to Solr, add a Warning item to the StartupStatus.
+ */
+public class SolrSmokeTest implements ServletContextListener {
+
+	@Override
+	public void contextInitialized(ServletContextEvent sce) {
+		final StartupStatus ss = StartupStatus.getBean(sce.getServletContext());
+
+		String solrUrlString = ConfigurationProperties.getBean(sce)
+				.getProperty("vitro.local.solr.url", "");
+		if (solrUrlString.isEmpty()) {
+			ss.fatal(this, "Can't connect to Solr search engine. "
+					+ "deploy.properties must contain a value for "
+					+ "vitro.local.solr.url");
+			return;
+		}
+
+		URL solrUrl = null;
+
+		try {
+			solrUrl = new URL(solrUrlString);
+		} catch (MalformedURLException e) {
+			ss.fatal(this, "Can't connect to Solr search engine. "
+					+ "The value for vitro.local.solr.url "
+					+ "in deploy.properties is not a valid URL: '"
+					+ solrUrlString + "'", e);
+		}
+
+		ss.info(this, "Starting thread for Solr test.");
+		new SolrSmokeTestThread(this, solrUrl, ss).start();
+	}
+
+	@Override
+	public void contextDestroyed(ServletContextEvent sce) {
+		// nothing to tear down.
+	}
+
+	private static class SolrSmokeTestThread extends VitroBackgroundThread {
+		private final SolrSmokeTest listener;
+		private final URL solrUrl;
+		private final StartupStatus ss;
+
+		public SolrSmokeTestThread(SolrSmokeTest listener, URL solrUrl,
+				StartupStatus ss) {
+			super("SolrSmokeTest");
+			this.listener = listener;
+			this.solrUrl = solrUrl;
+			this.ss = ss;
+		}
+
+		@Override
+		public void run() {
+			HttpClient client = new HttpClient();
+			GetMethod method = new GetMethod(solrUrl.toExternalForm());
+			try {
+				int statusCode = client.executeMethod(method);
+				method.getResponseBody();
+
+				if (statusCode == HttpStatus.SC_OK) {
+					reportSuccess();
+				} else if (statusCode == HttpStatus.SC_FORBIDDEN) {
+					warnForbidden();
+				} else {
+					warnBadHttpStatus(statusCode);
+				}
+			} catch (HttpException e) {
+				warnProtocolViolation(e);
+			} catch (IOException e) {
+				warnTransportError(e);
+			} finally {
+				method.releaseConnection();
+			}
+		}
+
+		private void reportSuccess() {
+			ss.info(listener,
+					"Successfully connected to the Solr search engine.");
+		}
+
+		private void warnForbidden() {
+			ss.warning(listener, "Can't connect to the Solr search engine. "
+					+ "The server will not accept connections from this host. "
+					+ "Check the value of vitro.local.solr.ipaddress.mask "
+					+ "in deploy.properties");
+		}
+
+		private void warnBadHttpStatus(int status) {
+			ss.warning(listener, "Can't connect to the Solr search engine. "
+					+ "The server returned a status code of " + status
+					+ ". Check the value of vitro.local.solr.url in "
+					+ "deploy.properties.");
+		}
+
+		private void warnProtocolViolation(HttpException e) {
+			ss.warning(listener, "Can't connect to the Solr search engine. "
+					+ "Detected a protocol violation: " + e.getMessage(), e);
+		}
+
+		private void warnTransportError(IOException e) {
+			ss.warning(listener, "Can't connect to the Solr search engine. "
+					+ "Detected a transport error: " + e.getMessage(), e);
+		}
+
+	}
+}

webapp/web/WEB-INF/resources/startup_listeners.txt

@@ -58,3 +58,6 @@ edu.cornell.mannlib.vitro.webapp.controller.freemarker.FreemarkerSetup
 org.apache.commons.fileupload.servlet.FileCleanerCleanup
 
 edu.cornell.mannlib.vitro.webapp.dao.jena.VClassGroupCache$Setup
+
+# This should be near the end, because it will issue a warning if the connection to Solr times out.
+edu.cornell.mannlib.vitro.webapp.servlet.setup.SolrSmokeTest