wamblee.org Git - utils/blob - system/general/src/main/java/org/wamblee/system/CompositeSystem.java

   1 package org.wamblee.system;
   2
   3 import java.util.ArrayList;
   4 import java.util.Arrays;
   5 import java.util.List;
   6
   7 import org.apache.commons.logging.Log;
   8 import org.apache.commons.logging.LogFactory;
   9
  10 import sun.util.LocaleServiceProviderPool.LocalizedObjectGetter;
  11
  12 /**
  13  * Composite system consisting of multiple subsystems.
  14  *
  15  * @author Erik Brakkee
  16  */
  17 public class CompositeSystem extends AbstractSubSystem {
  18
  19         private static final Log LOG = LogFactory.getLog(CompositeSystem.class);
  20
  21         private SubSystem[] _systems;
  22
  23         /**
  24          * Construcst the composite system.
  25          * @param aName Name of the system.
  26          * @param aRegistry Service registry.
  27          * @param aSystems Subsystems.
  28          * @param aProvided Provided services of the system.
  29          * @param aRequired Required services by the system.
  30          */
  31         public CompositeSystem(String aName, ServiceRegistry aRegistry, SubSystem[] aSystems,
  32                         ServiceDescriptor[] aProvided, ServiceDescriptor[] aRequired) {
  33                 super(aName, aRegistry, aProvided, aRequired);
  34                 _systems = aSystems;
  35                 validate();
  36         }
  37
  38         /**
  39          * Validates the subsystems together to check that there are
  40          * no required services not in the required list and
  41          * no services in the provided list that cannot be provided.
  42          * Also logs a warning in case of superfluous requirements.
  43          */
  44         private void validate() {
  45                 List<ServiceDescriptor> provided = new ArrayList<ServiceDescriptor>();
  46                 for (SubSystem system : _systems) {
  47                         provided.addAll(Arrays.asList(system.getProvidedServices()));
  48                 }
  49
  50                 List<ServiceDescriptor> required = new ArrayList<ServiceDescriptor>();
  51                 for (SubSystem system : _systems) {
  52                         required.addAll(Arrays.asList(system.getRequiredServices()));
  53                 }
  54
  55                 for (ServiceDescriptor service : getProvidedServices()) {
  56                         if (!(provided.contains(service))) {
  57                                 throw new SystemAssemblyException(getName() + ": Service '" + service
  58                                                 + "' is not provided by any of the subsystems");
  59                         }
  60                 }
  61
  62                 for (ServiceDescriptor service : getRequiredServices()) {
  63                         if (!(required.contains(service))) {
  64                                 info("Service '"
  65                                                 + service
  66                                                 + "' indicated as required is not actually required by any of the subsystems");
  67                         }
  68                 }
  69
  70                 List<ServiceDescriptor> reallyRequired = new ArrayList<ServiceDescriptor>(
  71                                 required);
  72                 for (ServiceDescriptor service : provided) {
  73                         reallyRequired.remove(service);
  74                 }
  75                 for (ServiceDescriptor service: getRequiredServices()) {
  76                         reallyRequired.remove(service);
  77                 }
  78                 for (ServiceDescriptor service: reallyRequired) {
  79                         throw new SystemAssemblyException(getName() + ": " + "Service '" + service + "' is not provided internally and is not indicated as required for this sub system");
  80                 }
  81         }
  82
  83         @Override
  84         protected void doStart(String aContext, Service[] aRequiredServices) {
  85                 List<ProvidedServiceDescriptor> descriptors = new ArrayList<ProvidedServiceDescriptor>();
  86                 for (Service service : aRequiredServices) {
  87                         descriptors.add(service.getDescriptor());
  88                 }
  89                 SystemAssembler assembler = new SystemAssembler(aContext + "." + getName(), _systems,
  90                                 descriptors.toArray(new ProvidedServiceDescriptor[0]));
  91                 assembler.start(getRegistry(), aRequiredServices);
  92         }
  93
  94         @Override
  95         protected void doStop() {
  96                 // Empty.
  97         }
  98
  99         private void info(String aMsg) {
 100                 LOG.info(getName() + ": " + aMsg);
 101         }
 102
 103 }