/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.apache.ignite.startup.servlet;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import org.apache.ignite.Ignite;
import org.apache.ignite.IgniteCheckedException;
import org.apache.ignite.configuration.IgniteConfiguration;
import org.apache.ignite.internal.IgnitionEx;
import org.apache.ignite.internal.processors.resource.GridSpringResourceContext;
import org.apache.ignite.internal.util.typedef.G;
import org.apache.ignite.internal.util.typedef.internal.S;
import org.apache.ignite.internal.util.typedef.internal.U;
import org.apache.ignite.lang.IgniteBiTuple;
/**
* This class defines servlet-based Ignite startup. This startup can be used to start Ignite
* inside any web container as servlet.
* <p>
* This startup must be defined in {@code web.xml} file.
* <pre name="code" class="xml">
* <servlet>
* <servlet-name>Ignite</servlet-name>
* <servlet-class>org.apache.ignite.startup.servlet.ServletStartup</servlet-class>
* <init-param>
* <param-name>cfgFilePath</param-name>
* <param-value>config/default-config.xml</param-value>
* </init-param>
* <load-on-startup>1</load-on-startup>
* </servlet>
* </pre>
* <p>
* Servlet-based startup may be used in any web container like Tomcat, Jetty and etc.
* Depending on the way this startup is deployed the Ignite instance can be accessed
* by either all web applications or by only one. See web container class loading architecture:
* <ul>
* <li><a target=_blank href="http://tomcat.apache.org/tomcat-7.0-doc/class-loader-howto.html">http://tomcat.apache.org/tomcat-7.0-doc/class-loader-howto.html</a></li>
* <li><a target=_blank href="http://docs.codehaus.org/display/JETTY/Classloading">http://docs.codehaus.org/display/JETTY/Classloading</a></li>
* </ul>
* <p>
* <h2 class="header">Tomcat</h2>
* There are two ways to start Ignite on Tomcat.
* <ul>
* <li>Ignite started when web container starts and Ignite instance is accessible only to all web applications.
* <ol>
* <li>Add Ignite libraries in Tomcat common loader.
* Add in file {@code $TOMCAT_HOME/conf/catalina.properties} for property {@code shared.loader}
* the following {@code $IGNITE_HOME/ignite.jar,$IGNITE_HOME/libs/*.jar}
* (replace {@code $IGNITE_HOME} with absolute path).
* </li>
* <li>Configure startup in {@code $TOMCAT_HOME/conf/web.xml}
* <pre name="code" class="xml">
* <servlet>
* <servlet-name>Ignite</servlet-name>
* <servlet-class>org.apache.ignite.startup.servlet.ServletStartup</servlet-class>
* <init-param>
* <param-name>cfgFilePath</param-name>
* <param-value>config/default-config.xml</param-value>
* </init-param>
* <load-on-startup>1</load-on-startup>
* </servlet>
* </pre>
* </li>
* </ol>
* </li>
* <li>
* Ignite started from WAR-file and Ignite instance is accessible only to that web application.
* Difference with approach described above is that {@code web.xml} file and all libraries should
* be added in WAR file without changes in Tomcat configuration files.
* </li>
* </ul>
* <p>
* <h2 class="header">Jetty</h2>
* Below is Java code example with Jetty API:
* <pre name="code" class="java">
* Server service = new Server();
*
* service.addListener("localhost:8090");
*
* ServletHttpContext ctx = (ServletHttpContext)service.getContext("/");
*
* ServletHolder servlet = ctx.addServlet("Ignite", "/IgniteStartup",
* "org.apache.ignite.startup.servlet.ServletStartup");
*
* servlet.setInitParameter("cfgFilePath", "config/default-config.xml");
*
* servlet.setInitOrder(1);
*
* servlet.start();
*
* service.start();
* </pre>
*/
public class ServletStartup extends HttpServlet {
/** */
private static final long serialVersionUID = 0L;
/** Grid loaded flag. */
private static boolean loaded;
/** Configuration file path variable name. */
private static final String cfgFilePathParam = "cfgFilePath";
/** */
private Collection<String> igniteInstanceNames = new ArrayList<>();
/** {@inheritDoc} */
@SuppressWarnings({"unchecked"})
@Override public void init() throws ServletException {
// Avoid multiple servlet instances. Ignite should be loaded once.
if (loaded)
return;
String cfgFile = getServletConfig().getInitParameter(cfgFilePathParam);
if (cfgFile == null)
throw new ServletException("Failed to read property: " + cfgFilePathParam);
URL cfgUrl = U.resolveIgniteUrl(cfgFile);
if (cfgUrl == null)
throw new ServletException("Failed to find Spring configuration file (path provided should be " +
"either absolute, relative to IGNITE_HOME, or relative to META-INF folder): " + cfgFile);
try {
IgniteBiTuple<Collection<IgniteConfiguration>, ? extends GridSpringResourceContext> t =
IgnitionEx.loadConfigurations(cfgUrl);
Collection<IgniteConfiguration> cfgs = t.get1();
if (cfgs == null)
throw new ServletException("Failed to find a single grid factory configuration in: " + cfgUrl);
for (IgniteConfiguration cfg : cfgs) {
assert cfg != null;
IgniteConfiguration adapter = new IgniteConfiguration(cfg);
Ignite ignite = IgnitionEx.start(adapter, t.get2());
// Test if grid is not null - started properly.
if (ignite != null)
igniteInstanceNames.add(ignite.name());
}
}
catch (IgniteCheckedException e) {
// Stop started grids only.
for (String name: igniteInstanceNames)
G.stop(name, true);
throw new ServletException("Failed to start Ignite.", e);
}
loaded = true;
}
/** {@inheritDoc} */
@Override public void destroy() {
// Stop started grids only.
for (String name: igniteInstanceNames)
G.stop(name, true);
loaded = false;
}
/** {@inheritDoc} */
@Override public String toString() {
return S.toString(ServletStartup.class, this);
}
}