Question

I want to make a plugin for Eclipse. The thing is that I looked into the API, and examples, and I managed to make a button on main bar, with a specific icon, and when I click it, open up an InputDialog.

The hard part, is that I want to start an aplication from this button, but not with Runtime as it was a new process. I simply want to start a class inside plugin, which will log in to a server and get some output from it. I want it to be opened in a console, like launching a normal application, or a separate console.

The best example of this kind is a Tomcat plugin which starts Tomcat, and then outputs the console to the Eclipse console. I want to do that too. I’ve looked at the Tomcat source plugin, but I got stuck there too. They use their own launcher.

Answer 1

I am not sure what you mean by “I want to simply start a class”. I assume there is a command line tool that you want to execute and redirect its output to the console window.

To be able to do that without spawning a new process, you have to be able to control the output stream of the tool. If it cannot be controlled, then you have no choice but to start a new process to properly capture the tool’s output.

It is technically possible to call System.setOut instead, but it will redirect output from all threads to your console which is not what you want.

Nevertheless you start by creating a console:

// function findConsole copied from:
// http://wiki.eclipse.org/FAQ_How_do_I_write_to_the_console_from_a_plug-in%3F
private MessageConsole findConsole(String name) {
    ConsolePlugin plugin = ConsolePlugin.getDefault();
    IConsoleManager conMan = plugin.getConsoleManager();
    IConsole[] existing = conMan.getConsoles();
    for (int i = 0; i < existing.length; i++)
       if (name.equals(existing[i].getName()))
          return (MessageConsole) existing[i];
    //No console found, so create a new one.
    MessageConsole myConsole = new MessageConsole(name, null);
    conMan.addConsoles(new IConsole[]{myConsole});
    return myConsole;
}

// Find my console
MessageConsole cons = findConsole("MyTool Console");
MessageConsoleStream out = cons.newMessageStream();

// Optionally get it's input stream so user can interact with my tool
IOConsoleInputStream in = cons.getInputStream();

// Optionally make a differently coloured error stream
MessageConsoleStream err = cons.newMessageStream();
err.setColor(display.getSystemColor(SWT.COLOR_RED));

// Display the console.
// Obtain the active page. See: http://wiki.eclipse.org/FAQ_How_do_I_find_the_active_workbench_page%3F
IWorkbenchPage page = ...;
String id = IConsoleConstants.ID_CONSOLE_VIEW;
IConsoleView view = (IConsoleView) page.showView(id);
view.display(cons);

Then set the input and output streams of my tool and start processing in a different thread so the UI will not block.

// Create my tool and redirect its output
final MyTool myTool = new MyTool();
myTool.setOutputStream(out);
myTool.setErrorStream(err);
myTool.setInputStream(in);

// Start it in another thread
Thread t = new Thread(new Runnable() {
    public void run() {
        myTool.startExecuting();
    }
});
t.start();

If your tool does not support I/O redirection, you have no choice but to start it in another process with the ProcessBuilder and use a number of threads to move data between console and process streams See: Process.getInputStream(), Process.getOutputStream() and Process.getErrorStream().

The following links have additional useful details:

• Executing a Java application in a separate process
• FAQ How do I write to the console from a plug-in?
• FAQ How do I find the active workbench page?