/*
* Copyright 2013 Red Hat, Inc. and/or its affiliates.
*
* 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 org.jbpm.executor.impl;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.kie.api.executor.Command;
import org.kie.api.executor.CommandCallback;
import org.kie.api.executor.CommandContext;
import org.kie.internal.runtime.Cacheable;
import org.kie.internal.runtime.Closeable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Simple cache to keep classes of commands and callback to not attempt to load them every time.
*
*/
public class ClassCacheManager {
private static final Logger logger = LoggerFactory.getLogger(ClassCacheManager.class);
private final Map<String, Command> commandCache = new HashMap<String, Command>();
private final Map<String, CommandCallback> callbackCache = new HashMap<String, CommandCallback>();
/**
* Finds command by FQCN and if not found loads the class and store the instance in
* the cache.
* @param name - fully qualified class name of the command
* @return initialized class instance
*/
public Command findCommand(String name, ClassLoader cl) {
synchronized (commandCache) {
if (!commandCache.containsKey(name)) {
try {
Command commandInstance = (Command) Class.forName(name, true, cl).newInstance();
commandCache.put(name, commandInstance);
} catch (Exception ex) {
throw new IllegalArgumentException("Unknown Command implementation with name '" + name + "'");
}
} else {
Command cmd = commandCache.get(name);
if (!cmd.getClass().getClassLoader().equals(cl)) {
commandCache.remove(name);
try {
Command commandInstance = (Command) Class.forName(name, true, cl).newInstance();
commandCache.put(name, commandInstance);
} catch (Exception ex) {
throw new IllegalArgumentException("Unknown Command implementation with name '" + name + "'");
}
}
}
}
return commandCache.get(name);
}
/**
* Finds command callback by FQCN and if not found loads the class and store the instance in
* the cache.
* @param name - fully qualified class name of the command callback
* @return initialized class instance
*/
public CommandCallback findCommandCallback(String name, ClassLoader cl) {
synchronized (callbackCache) {
if (!callbackCache.containsKey(name)) {
try {
CommandCallback commandCallbackInstance = (CommandCallback) Class.forName(name, true, cl).newInstance();
return commandCallbackInstance;
// callbackCache.put(name, commandCallbackInstance);
} catch (Exception ex) {
throw new IllegalArgumentException("Unknown Command implementation with name '" + name + "'");
}
} else {
CommandCallback cmdCallback = callbackCache.get(name);
if (!cmdCallback.getClass().getClassLoader().equals(cl)) {
callbackCache.remove(name);
try {
CommandCallback commandCallbackInstance = (CommandCallback) Class.forName(name, true, cl).newInstance();
callbackCache.put(name, commandCallbackInstance);
} catch (Exception ex) {
throw new IllegalArgumentException("Unknown Command implementation with name '" + name + "'");
}
}
}
}
return callbackCache.get(name);
}
/**
* Builds completely initialized list of callbacks for given context.
* @param ctx contextual data given by execution service
* @return
*/
public List<CommandCallback> buildCommandCallback(CommandContext ctx, ClassLoader cl) {
List<CommandCallback> callbackList = new ArrayList<CommandCallback>();
if (ctx != null && ctx.getData("callbacks") != null) {
logger.debug("Callback: {}", ctx.getData("callbacks"));
String[] callbacksArray = ((String) ctx.getData("callbacks")).split(",");
List<String> callbacks = (List<String>) Arrays.asList(callbacksArray);
for (String callbackName : callbacks) {
CommandCallback handler = findCommandCallback(callbackName.trim(), cl);
callbackList.add(handler);
}
}
return callbackList;
}
protected void closeInstance(Object instance) {
if (instance == null) {
return;
}
if (instance instanceof Closeable) {
((Closeable) instance).close();
} else if (instance instanceof Cacheable) {
((Cacheable) instance).close();
}
}
public void dispose() {
if (commandCache != null) {
for (Object command : commandCache.values()) {
closeInstance(command);
}
}
if (callbackCache != null) {
for (Object callback : callbackCache.values()) {
closeInstance(callback);
}
}
}
}