legacy/runtime/org.argeo.slc.detached/src/main/java/org/argeo/slc/detached/DetachedServer.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.argeo.slc.detached;
  17
  18 import org.apache.commons.logging.Log;
  19 import org.apache.commons.logging.LogFactory;
  20 import org.osgi.framework.BundleContext;
  21 import org.osgi.framework.Constants;
  22 import org.springframework.beans.BeansException;
  23 import org.springframework.context.ApplicationContext;
  24 import org.springframework.context.ApplicationContextAware;
  25 import org.springframework.osgi.context.BundleContextAware;
  26
  27 /**
  28  * When started, processes <code>DetachedRequest</code> through a
  29  * <code>DetachedExecutionServer</code> and sends <code>DetachedAnswer</code>
  30  * back
  31  */
  32 public class DetachedServer implements BundleContextAware, ApplicationContextAware {
  33
  34         private final static Log log = LogFactory.getLog(DetachedServer.class);
  35
  36         private boolean active = true;
  37         private DetachedExecutionServer executionServer = null;
  38
  39         private boolean cacheObjects = true;
  40
  41         /** May be null */
  42         private ApplicationContext applicationContext;
  43         /** May be null */
  44         private BundleContext bundleContext;
  45
  46         /**
  47          * Used to receive Request and send answers
  48          */
  49         private DetachedDriver detachedDriver;
  50
  51         public synchronized void start() {
  52
  53                 log.info("Starting DetachedServer");
  54
  55                 Thread driverThread = new Thread(new Runnable() {
  56
  57                         public void run() {
  58                                 while (active) {
  59                                         try {
  60                                                 // no timeout to receive a request
  61                                                 DetachedRequest request = detachedDriver.receiveRequest();
  62                                                 if (!active)
  63                                                         break;
  64
  65                                                 String driverBundleName = null;
  66                                                 if (bundleContext != null)
  67                                                         driverBundleName = bundleContext.getBundle()
  68                                                                         .getSymbolicName();
  69
  70                                                 if (applicationContext != null && cacheObjects) {
  71                                                         try {
  72                                                                 String ref = request.getRef();
  73                                                                 if (applicationContext.containsBean(ref)) {
  74                                                                         Object obj = applicationContext
  75                                                                                         .getBean(request.getRef());
  76                                                                         request.setCachedObject(obj);
  77                                                                         if (log.isTraceEnabled())
  78                                                                                 log.trace("Cached bean '" + ref
  79                                                                                                 + "' in request " + request);
  80                                                                 } else {
  81                                                                         log
  82                                                                                         .warn("Cannot cache object in request because no bean '"
  83                                                                                                         + ref
  84                                                                                                         + "' was found in application context"
  85                                                                                                         + (driverBundleName != null ? " (driver bundle "
  86                                                                                                                         + driverBundleName
  87                                                                                                                         + ")"
  88                                                                                                                         : ""));
  89                                                                 }
  90                                                         } catch (Exception e) {
  91                                                                 if (log.isTraceEnabled())
  92                                                                         log
  93                                                                                         .trace("Could not retrieve "
  94                                                                                                         + request.getRef()
  95                                                                                                         + " from driver application context because of "
  96                                                                                                         + e);
  97                                                                 driverBundleName = null;// do not publish bundle
  98                                                                                                                 // name
  99                                                         }
 100                                                 }
 101
 102                                                 if (driverBundleName != null)
 103                                                         request.getProperties().put(
 104                                                                         Constants.BUNDLE_SYMBOLICNAME,
 105                                                                         driverBundleName);
 106
 107                                                 DetachedAnswer answer = executionServer
 108                                                                 .executeRequest(request);
 109                                                 detachedDriver.sendAnswer(answer);
 110                                         } catch (Exception e) {
 111                                                 // if (e instanceof RuntimeException)
 112                                                 // throw (RuntimeException) e;
 113                                                 // else
 114                                                 e.printStackTrace();
 115                                         }
 116                                 }
 117
 118                         }
 119                 }, "driverThread (" + getClass() + ")");
 120                 driverThread.start();
 121
 122         }
 123
 124         public void setExecutionServer(DetachedExecutionServer executionServer) {
 125                 this.executionServer = executionServer;
 126         }
 127
 128         public synchronized void stop() {
 129                 active = false;
 130                 notifyAll();
 131         }
 132
 133         public synchronized boolean isActive() {
 134                 return active;
 135         }
 136
 137         public synchronized void setActive(boolean active) {
 138                 this.active = active;
 139         }
 140
 141         public void setApplicationContext(ApplicationContext applicationContext)
 142                         throws BeansException {
 143                 this.applicationContext = applicationContext;
 144         }
 145
 146         public void setBundleContext(BundleContext bundleContext) {
 147                 this.bundleContext = bundleContext;
 148         }
 149
 150         public void setCacheObjects(boolean cacheObjects) {
 151                 this.cacheObjects = cacheObjects;
 152         }
 153
 154         public void setDetachedDriver(DetachedDriver detachedDriver) {
 155                 this.detachedDriver = detachedDriver;
 156         }
 157
 158 }