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package com.sos.scheduler.engine.kernel.plugin;
import com.sos.scheduler.engine.kernel.command.CommandHandler;
import com.sos.scheduler.engine.kernel.AbstractHasPlatform;
import com.sos.scheduler.engine.kernel.Scheduler;
import com.sos.scheduler.engine.kernel.SchedulerException;
import com.sos.scheduler.engine.kernel.Subsystem;
import com.sos.scheduler.engine.kernel.command.HasCommandHandlers;
import com.sos.scheduler.engine.kernel.log.PrefixLog;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import org.w3c.dom.Element;
import static com.sos.scheduler.engine.kernel.util.Util.stackTrace;
import static com.sos.scheduler.engine.kernel.util.XmlUtils.*;
import static java.util.Arrays.asList;
//TODO Eigenes PrefixLog einführen
public class PlugInSubsystem extends AbstractHasPlatform implements Subsystem, HasCommandHandlers {
private static final String staticFactoryMethodName = "factory";
private final Scheduler scheduler;
private final Map<String,PluginAdapter> plugIns = new HashMap<String,PluginAdapter>();
private final CommandHandler[] commandHandlers = {
new PlugInCommandExecutor(this),
new PlugInCommandCommandXmlParser(this),
new PluginCommandResultXmlizer(this) };
public PlugInSubsystem(Scheduler scheduler) {
super(scheduler.getPlatform());
this.scheduler = scheduler;
}
public final void load(Element root) {
Element plugInsElement = elementXPathOrNull(root, "config/plugins");
if (plugInsElement != null) {
for (Element e: elementsXPath(plugInsElement, "plugin")) tryAddPlugIn(e);
}
}
private void tryAddPlugIn(Element e) {
String className = e.getAttribute("java_class");
if (className.isEmpty()) throw new SchedulerException("Missing attribute java_class in <plugin>");
Element contentElement = elementXPathOrNull(e, "plugin.config");
tryAddPlugIn(className, contentElement);
}
private void tryAddPlugIn(String className, Element elementOrNull) {
try {
PlugIn p = newPlugIn(className, elementOrNull);
PluginAdapter a = p instanceof CommandPlugin? new CommandPluginAdapter((CommandPlugin)p, className, log())
: new PluginAdapter(p, className, log());
plugIns.put(className, a);
log().info(a + " added");
} catch (Exception x) {
logError(log(), "Plug-in " + className, x);
}
}
private PlugIn newPlugIn(String className, Element elementOrNull) throws Exception {
Class<?> c = Class.forName(className);
PlugInFactory f = (PlugInFactory)c.getMethod(staticFactoryMethodName).invoke(null);
return f.newInstance(scheduler, elementOrNull);
}
public final void activate() {
for (PluginAdapter p: plugIns.values()) p.tryActivate();
}
public final void close() {
for (PluginAdapter p: plugIns.values()) p.tryClose();
}
final CommandPluginAdapter commandPluginByClassName(String className) {
PluginAdapter a = pluginByClassName(className);
if (!(a instanceof CommandPluginAdapter))
throw new SchedulerException("Plugin is not a " + CommandPlugin.class.getSimpleName());
return (CommandPluginAdapter)a;
}
private PluginAdapter pluginByClassName(String className) {
PluginAdapter result = plugIns.get(className);
if (result == null)
throw new SchedulerException("Unknown plugin '" + className + "'");
return result;
}
@Override public final Collection<CommandHandler> getCommandHandlers() {
return asList(commandHandlers);
}
static void logError(PrefixLog log, String pluginName, Throwable t) {
log.error(pluginName + ": " + t + "\n" + stackTrace(t));
}
}