java.awt.Trayicon 在 java 应用程序安装为 windows 7 服务时不显示

Question

I have installed my Java application as windows service on Windows 7(32 bit) OS. My application is expected to show java.awt.TrayIcon on notification area when service starts. But it is no showing the Icon. The same application is working fine on Windows XP. Anybody has any idea about that?

Answer 1

A service on windows is not graphical. Because it's running without any user loggued. If you want to have a Tray Icon and a graphical window to manage your service, you have to write another program which communicate with your service (local network, dcom,...) and add this program to the session startup. (It's in that way I've done my own java service on my computers).

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Ok, I've worked under Windows server 2003. Maybe service can't have GUI since windows 2003?

The code you have to develop depends on what you want? Just have a trayicon to monitor that te service process is still running? Display a parameters windows when clicking on the systray?...

I've put you a simple code (without exception management to clarify the code) to monitor that the service is still running and responding (this is a standard java code, no special lib need):

The systray program:

//if any Exception --> ERROR CODE
Socket socket = new Socket("localhost", 25146);
DataOutputStream outToServer = new DataOutputStream(socket.getOutputStream());
BufferedReader inFromUser = new BufferedReader(new InputStreamReader(socket.getInputStream()));
while (true) {
    outToServer.writeBytes("ping\n");
    //Wait maximum 5s to have an answer from the service
    for (int i = 0; inFromUser.ready() == false && i < 5; ++i) {
        Thread.sleep(1000);
    }
    if (inFromUser.ready() == false) {
        //ERROR CODE (change systrat icon, display balloon tooltip,...)
    } else {
        pong = inFromUser.readLine();
        //Check the answer
    }   

    //Check only every second (don't flood yout computer ;))
    Thread.sleep(1000);
}
inFromUser.close();
outToServer.close();
socket.close();

The service program code:

ServerSocket socket = new ServerSocket(this._port);
while (true) {
    Socket connection = socket.accept();
    Thread thread = new Thread(new Runnable {
        BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connection.getInputStream()));
        DataOutputStream outToClient = new DataOutputStream(connection.getOutputStream());
        Scanner scanner = new Scanner(inFromClient);
        while (scanner.hasNextLine()) {
            outToClient.writeBytes(scanner.nextLine());     
        }
        inFromClient.close();
        outToClient.close();
        connection.close();     
    });
    thread.start();
}

If you want to popup a parameter window, you can try either to writer the GUI in your systray program, write the result into a parameter file, and send a special keyword to your service to reload the parameters files... or either to write the GUI directly into your service, send a special keyword, and then do a jframe.setVisible(true) and hope it will be display on the current session... :)

Answer 2

Microsoft changed how interactive services work back in 2006. What worked in Windows NT, XP and Server 2003 no longer work in Vista, 7 or Server 2008 thanks to "Session 0 Isolation".

Read more here:

• http://www.coretechnologies.com/WindowsServices/FAQ.html#WhatIsSession0Isolation
• http://www.coretechnologies.com/WindowsServices/FAQ.html#GUIServices