net.sf.appstatus.web.StatusServlet.java Source code

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Here is the source code for net.sf.appstatus.web.StatusServlet.java

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/*
 * Copyright 2010 Capgemini
 * 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 net.sf.appstatus.web;

import java.io.IOException;
import java.util.LinkedHashMap;
import java.util.Map;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.sf.appstatus.core.AppStatus;
import net.sf.appstatus.core.AppStatusStatic;
import net.sf.appstatus.core.IServletContextProvider;
import net.sf.appstatus.web.pages.BatchPage;
import net.sf.appstatus.web.pages.LoggersPage;
import net.sf.appstatus.web.pages.RadiatorPage;
import net.sf.appstatus.web.pages.ServicesPage;
import net.sf.appstatus.web.pages.StatusPage;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class StatusServlet extends HttpServlet {

    private static Logger logger = LoggerFactory.getLogger(AppStatus.class);
    private static final long serialVersionUID = 3912325072098291029L;
    private static StatusWebHandler statusWeb = null;

    private void addPage(Map<String, IPage> map, IPage page) {
        map.put(page.getId(), page);
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest
     * , javax.servlet.http.HttpServletResponse)
     */
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        statusWeb.doGet(req, resp);
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest
     * , javax.servlet.http.HttpServletResponse)
     */
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        statusWeb.doPost(req, resp);
    }

    /**
     * Init the AppStatus Web UI.
     * <p>
     * Read <b>bean</> init parameter. If defined, switch to Spring-enabled
     * behavior.
     */
    @Override
    public void init(ServletConfig config) throws ServletException {
        super.init(config);

        super.init();

        SpringObjectInstantiationListener instantiation = null;
        String beanName = getInitParameter("bean");
        String[] pagesBeanNames = StringUtils.split(getInitParameter("custom-pages"), ", ");
        Map<String, IPage> pages = new LinkedHashMap<String, IPage>();
        ;

        AppStatus status;
        if (beanName != null) {
            // Using Spring
            instantiation = new SpringObjectInstantiationListener(this.getServletContext());

            // Status
            status = (AppStatus) instantiation.getInstance(beanName);

        } else {
            status = AppStatusStatic.getInstance();

        }

        status.setServletContextProvider(new IServletContextProvider() {
            public ServletContext getServletContext() {
                return StatusServlet.this.getServletContext();
            }
        });

        //
        // Pages
        addPage(pages, new StatusPage());

        if (status.getServiceManager() != null) {
            addPage(pages, new ServicesPage());
        }

        if (status.getBatchManager() != null) {
            addPage(pages, new BatchPage());

        }

        if (status.getLoggersManager() != null) {
            addPage(pages, new LoggersPage());

        }

        // Custom pages
        if (pagesBeanNames != null) {
            for (String pageBean : pagesBeanNames) {

                IPage newPage = null;

                if (instantiation != null) {
                    newPage = (IPage) instantiation.getInstance(pageBean);
                    if (newPage == null) {
                        try {
                            newPage = (IPage) Thread.currentThread().getContextClassLoader().loadClass(pageBean)
                                    .newInstance();
                        } catch (ClassNotFoundException e) {
                            logger.warn("Class {} not found ", pageBean, e);
                        } catch (InstantiationException e) {
                            logger.warn("Cannot instanciate {} ", pageBean, e);
                        } catch (IllegalAccessException e) {
                            logger.warn("Cannot access class {} for instantiation ", pageBean, e);
                        }
                    }
                }

                addPage(pages, newPage);

            }
        }

        // Radiator at the end.
        addPage(pages, new RadiatorPage());

        // Init
        statusWeb = new StatusWebHandler();
        statusWeb.setAppStatus(status);
        statusWeb.setApplicationName(
                StringUtils.defaultString(config.getServletContext().getServletContextName(), "No name"));
        statusWeb.setPages(pages);
        statusWeb.init();
    }
}