LightPIT: src/java/de/uapcore/lightpit/ModuleManager.java@598670d5b0b8

core functionality should also use the modules system, changed the code structure accordingly

     1 /*

     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

     3  *

     4  * Copyright 2017 Mike Becker. All rights reserved.

     5  *

     6  * Redistribution and use in source and binary forms, with or without

     7  * modification, are permitted provided that the following conditions are met:

     8  *

     9  *   1. Redistributions of source code must retain the above copyright

    10  *      notice, this list of conditions and the following disclaimer.

    11  *

    12  *   2. Redistributions in binary form must reproduce the above copyright

    13  *      notice, this list of conditions and the following disclaimer in the

    14  *      documentation and/or other materials provided with the distribution.

    15  *

    16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

    17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

    19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

    20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

    21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

    22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

    23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

    24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

    25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

    26  * POSSIBILITY OF SUCH DAMAGE.

    27  *

    28  */

    29 package de.uapcore.lightpit;

    31 import java.util.logging.Level;

    32 import java.util.logging.Logger;

    33 import javax.servlet.Registration;

    34 import javax.servlet.ServletContext;

    35 import javax.servlet.ServletContextEvent;

    36 import javax.servlet.ServletContextListener;

    37 import javax.servlet.annotation.WebListener;

    39 /**

    40  * Scans registered servlets for LightPIT modules.

    41  */

    42 @WebListener

    43 public class ModuleManager implements ServletContextListener {

    45     private static final Logger LOG = Logger.getLogger(ModuleManager.class.getName());

    47     /**

    48      * The attribute name in the servlet context under which an instance of this class can be found.

    49      */

    50     public static final String SC_ATTR_NAME = ModuleManager.class.getName();

    52     private ServletContext sc;

    54     @Override

    55     public void contextInitialized(ServletContextEvent sce) {

    56         sc = sce.getServletContext();

    57         reloadAll();

    58         sc.setAttribute(SC_ATTR_NAME, this);

    59         LOG.info("Module manager injected into ServletContext.");

    60     }

    62     @Override

    63     public void contextDestroyed(ServletContextEvent sce) {

    64         assert sc != null && sc.equals(sce.getServletContext());

    65         sc.removeAttribute(SC_ATTR_NAME);

    66         unloadAll();

    67     }

    69     private boolean isRegisteredAsModule(Registration reg) {

    70         try {

    71             final Class scclass = Class.forName(reg.getClassName());

    73             final boolean lpservlet = LightPITServlet.class.isAssignableFrom(scclass);

    74             final boolean lpmodule = scclass.isAnnotationPresent(LightPITModule.class);

    76             if (lpservlet && !lpmodule) {

    77                 LOG.log(Level.WARNING,

    78                     "Servlet is a LightPITServlet but is missing the module annotation: {0}",

    79                     reg.getClassName());

    80             } else if (!lpservlet && lpmodule) {

    81                 LOG.log(Level.WARNING,

    82                     "Servlet is annotated as a LightPITModule but does not extend LightPITServlet: {0}",

    83                     reg.getClassName());

    84             }

    86             return lpservlet && lpmodule;

    87         } catch (ClassNotFoundException ex) {

    88             LOG.log(Level.SEVERE,

    89                     "Servlet registration refers to a class which cannot be found by the class loader: {0}",

    90                     reg.getClassName());

    91             return false;

    92         }

    93     }

    95     private void handleServletRegistration(String name, Registration reg) {

    96         if (isRegisteredAsModule(reg)) {

    97             LOG.log(Level.CONFIG, "Module detected: {0}", name);

    98         } else {

    99             LOG.log(Level.FINE, "Servlet {0} is no module, skipping.", name);

   100         }

   101     }

   103     /**

   104      * Scans for modules and reloads them all.

   105      */

   106     public void reloadAll() {

   107         sc.getServletRegistrations().forEach(this::handleServletRegistration);

   108         LOG.info("Modules loaded.");

   109     }

   111     /**

   112      * Unloads all found modules.

   113      */

   114     public void unloadAll() {

   115         LOG.info("All modules unloaded.");

   116     }

   117 }

Mercurial > hg > LightPIT / file revision