org.metis.MetisServlet.java Source code

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Here is the source code for org.metis.MetisServlet.java

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/*
 * Copyright 2014 Joe Fernandez 
 *
 * Licensed 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.metis;

import java.util.Map;
import java.util.Iterator;

import javax.servlet.ServletException;

import org.springframework.web.servlet.DispatcherServlet;
import org.springframework.context.ApplicationContext;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.Log;
import org.metis.pull.WdsResourceBean;
import org.metis.push.PusherBean;

/**
 * This is the main dispatcher Servlet for Metis. It will dispatch http requests
 * on to the mapper, which maps the requests to resource or pusher beans.
 * 
 */
public class MetisServlet extends DispatcherServlet {

    private static final long serialVersionUID = -2808801234972854107L;

    private static final Log LOG = LogFactory.getLog(MetisServlet.class);

    private Map<String, WdsResourceBean> rdbs = null;
    private Map<String, PusherBean> pdbs = null;

    public MetisServlet() {
        super();
    }

    /**
     * This method will be invoked after all bean properties have been set and
     * the WebApplicationContext has been loaded.
     * 
     * @throws ServletException
     *             in case of an initialization exception
     */
    @Override
    protected void initFrameworkServlet() throws ServletException {
        super.initFrameworkServlet();

        if ((rdbs == null || rdbs.isEmpty()) && (pdbs == null || pdbs.isEmpty())) {
            throw new ServletException(getServletConfig().getServletName()
                    + ": There are neither resource nor pusher" + "beans defined for this web application context");
        }

        for (WdsResourceBean rdb : rdbs.values()) {
            if (!rdb.isDbConnectionAcquired()) {
                LOG.error(getServletConfig().getServletName() + ": this RDB was not able to get a "
                        + "connection to its data source: " + rdb.getBeanName());
                throw new ServletException(getServletConfig().getServletName() + ": this RDB was not able to get a "
                        + "connection to its data source: " + rdb.getBeanName());
            }
        }
        for (PusherBean pdb : pdbs.values()) {
            if (!pdb.isDbConnectionAcquired()) {
                LOG.error(getServletConfig().getServletName() + ": this PUSHER was not able to get a "
                        + "connection to its data source: " + pdb.getBeanName());
                throw new ServletException(
                        getServletConfig().getServletName() + ": this PUSHER was not able to get a "
                                + "connection to its data source: " + pdb.getBeanName());
            }
            // assign this servelt's name to the PDB
            pdb.setServletName(getServletName());
        }

    }

    /**
     * This is where we initialize the web application's strategy objects (rdbs,
     * pools, etc.) This method is called prior to initFrameworkServlet() being
     * called.
     */
    @Override
    protected void initStrategies(ApplicationContext context) {
        super.initStrategies(context);

        // Assign the resource bean this container's info
        WdsResourceBean.serverInfo = getServletContext().getServerInfo();

        // get list of all RDBs and PUSHERs for this application context
        rdbs = context.getBeansOfType(WdsResourceBean.class);
        pdbs = context.getBeansOfType(PusherBean.class);
        if (rdbs.isEmpty() && pdbs.isEmpty()) {
            LOG.error(getServletConfig().getServletName()
                    + ": Neither RDBs nor PUSHERs have been defined for this web application");
            return;
        }

        Boolean secure = null;
        String prop = getInitParameter("secure");
        if (prop != null) {
            secure = Boolean.valueOf(prop);
            LOG.debug(getServletConfig().getServletName() + ": secure = " + secure.booleanValue());
        }

        Boolean authenticated = null;
        prop = getInitParameter("authenticated");
        if (prop != null) {
            authenticated = Boolean.valueOf(prop);
            LOG.debug(getServletConfig().getServletName() + ": authenticated = " + authenticated.booleanValue());
        }

        String agentNames = getInitParameter("agentNames");
        if (agentNames != null) {
            LOG.debug(getServletConfig().getServletName() + ": agentNames = " + agentNames);
        }

        String cacheControl = getInitParameter("cacheControl");
        if (cacheControl != null) {
            LOG.debug(getServletConfig().getServletName() + ": cacheControl = " + cacheControl);
        }

        try {
            // assign global init properties to the RDBs
            for (Iterator<WdsResourceBean> it = rdbs.values().iterator(); it.hasNext();) {
                WdsResourceBean rdb = it.next();

                if (rdb.getAuthenticated() == null && authenticated != null) {
                    rdb.setAuthenticated(authenticated.booleanValue());
                }

                if (rdb.getSecure() == null && secure != null) {
                    rdb.setSecure(secure.booleanValue());
                }

                if (rdb.getAgentNames() == null && agentNames != null) {
                    rdb.setAgentNames(agentNames);
                }

                if (rdb.getCacheControl() == null && cacheControl != null) {
                    rdb.setCacheControl(cacheControl);
                }
            }

        } catch (Exception e) {
            LOG.error(getServletConfig().getServletName() + "initStrategies: ERROR, this exception was caught - "
                    + e.getLocalizedMessage());
        }
    }

    @Override
    public void destroy() {
        super.destroy();
        LOG.trace("destroy - enter");
    }
}