com.oracle.tools.runtime.java.JavaApplicationLauncher Maven / Gradle / Ivy
/*
* File: JavaApplicationLauncher.java
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* The contents of this file are subject to the terms and conditions of
* the Common Development and Distribution License 1.0 (the "License").
*
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the License by consulting the LICENSE.txt file
* distributed with this file, or by consulting https://oss.oracle.com/licenses/CDDL
*
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file LICENSE.txt.
*
* MODIFICATIONS:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
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package com.oracle.tools.runtime.java;
import com.oracle.tools.runtime.Settings;
import com.oracle.tools.runtime.concurrent.RemoteExecutor;
import com.oracle.tools.runtime.concurrent.RemoteExecutorListener;
import com.oracle.tools.runtime.concurrent.socket.RemoteExecutorClient;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.InetAddress;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.UnknownHostException;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* Used to launch {@link JavaApplication}s that connect back to their "parent"
* application so that they may be remotely controlled, request further information
* or may detect when they become orphaned (their parent is killed, destroyed or
* otherwise terminates).
*
* Copyright (c) 2013. All Rights Reserved. Oracle Corporation.
* Oracle is a registered trademark of Oracle Corporation and/or its affiliates.
*
* @author Brian Oliver
*/
public class JavaApplicationLauncher
{
/**
* {@link JavaApplicationLauncher} entry point.
*
* Usage: java JavaApplicationLauncher ApplicationClassName [args]
*
* Where: ApplicationClassName is the fully-qualified-class-name of the
* application to run (this class must
* have a standard main method declaration).
*
* args is a space separated list of arguments to pass to the
* application main method.
*
* @param arguments the arguments for the {@link JavaApplicationLauncher}
*/
public static void main(String[] arguments)
{
if (arguments.length == 0)
{
System.out
.println("JavaApplicationLauncher: No application (fqcn) was specified to start. An application must be specified as an argument.");
Runtime.getRuntime().halt(1);
}
else
{
final String parent = System.getProperty(Settings.PARENT_URI, null);
final boolean isOrphanable = Boolean.getBoolean(Settings.ORPHANABLE);
// a flag indicating if this application is in the process of
// shutting down naturally
// (System.exit(...) or main has finished and shutdown hooks have started)
final AtomicBoolean isShuttingDown = new AtomicBoolean(false);
// add a shutdown hook so we can tell when the application is
// terminating due to natural causes
// (like it's finished or a System.exit(...) was called)
Runtime.getRuntime().addShutdownHook(new Thread()
{
@Override
public void run()
{
isShuttingDown.set(true);
}
});
if (parent == null)
{
System.out
.println("JavaApplicationLauncher: No parent URI was specified. The parent URI must be specified to start the application.");
Runtime.getRuntime().halt(1);
}
else if (arguments.length >= 1)
{
String applicationClassName = arguments[0];
RemoteExecutorClient remoteExecutor = null;
// attempt to connect to the parent application
try
{
URI parentURI = new URI(parent);
// find the InetAddress of the host on which the parent is running
InetAddress inetAddress = InetAddress.getByName(parentURI.getHost());
// establish a RemoteExecutorClient to handle and send requests to the parent
remoteExecutor = new RemoteExecutorClient(inetAddress, parentURI.getPort());
remoteExecutor.addListener(new RemoteExecutorListener()
{
@Override
public void onOpened(RemoteExecutor executor)
{
// connected to the parent!
}
@Override
public void onClosed(RemoteExecutor executor)
{
// disconnected from the parent so terminate
// (if we're not orphanable)
if (!isOrphanable)
{
Runtime.getRuntime().halt(2);
}
}
});
// connect to the parent
remoteExecutor.open();
}
catch (URISyntaxException e)
{
System.out.println("JavaApplicationLauncher: The specified parent URI [" + parent + "] is invalid");
e.printStackTrace(System.out);
}
catch (UnknownHostException e)
{
System.out.println("JavaApplicationLauncher: The specified parent address is unknown");
e.printStackTrace(System.out);
}
catch (IOException e)
{
System.out.println("JavaApplicationLauncher: Failed to open a connection to parent");
e.printStackTrace(System.out);
if (remoteExecutor != null)
{
remoteExecutor.close();
remoteExecutor = null;
}
}
if (remoteExecutor != null)
{
// start the application
try
{
// attempt to load the application class
Class applicationClass = Class.forName(applicationClassName);
// create the real arguments for the application
String[] realArguments = new String[arguments.length - 1];
for (int i = 1; i < arguments.length; i++)
{
realArguments[i - 1] = arguments[i];
}
// now launch the application
Method mainMethod = applicationClass.getMethod("main", String[].class);
mainMethod.invoke(null, new Object[] {realArguments});
}
catch (ClassNotFoundException e)
{
System.out.println("JavaApplicationLauncher: Could not load the class " + applicationClassName);
e.printStackTrace(System.out);
}
catch (NoSuchMethodException e)
{
System.out.println("JavaApplicationLauncher: Could not locate a main method for "
+ applicationClassName);
e.printStackTrace(System.out);
}
catch (IllegalAccessException e)
{
System.out.println("JavaApplicationLauncher: Could not access the main method for "
+ applicationClassName);
e.printStackTrace(System.out);
}
catch (InvocationTargetException e)
{
System.out.println("JavaApplicationLauncher: Failed to invoke the main method for "
+ applicationClassName);
e.printStackTrace(System.out);
}
}
}
}
}
}