CODEWITHSUNDEEP
javaswingjvm
icespace
icespace

Reputation: 501

Active other process's window in Java

I have two Java swing applications (means running in two JVM). Is there any way to switch between them? Active another application's window by Java code?

Upvotes: 3

Views: 3264

Answers (1)

Xeon
Xeon

Reputation: 5989

You can try using JNA. I'll give you some code for Windows (more or less will be for other systems) using Maven: (sorry but I cannot get formatting right)

  1. Create Maven project, and add dependencies:

    <dependency>
    <groupId>net.java.dev.jna</groupId>
    <artifactId>jna</artifactId>
    <version>3.4.0</version>
</dependency>
<dependency>
    <groupId>net.java.dev.jna</groupId>
    <artifactId>platform</artifactId>
    <version>3.4.0</version>
</dependency>

  2. Create interface

    public interface User32 extends StdCallLibrary {
    User32 INSTANCE = (User32) Native.loadLibrary("user32", User32.class, W32APIOptions.DEFAULT_OPTIONS);
    HWND GetParent(HWND hWnd);
    HWND FindWindow(String lpClassName, String lpWindowName);
    HWND SetFocus(HWND hWnd);
    HWND FindWindowEx(HWND hwndParent, HWND hwndChildAfter, String lpszClass, String lpszWindow);
    int GetWindowText(HWND hWnd, char[] lpString, int nMaxCount);
}

  3. Create class

    public final class Win32WindowUtils {
    private static final int WIN_TITLE_MAX_SIZE = 512;

    public HWND GetWindowHandle(String strSearch, String strClass) {
        char[] lpString = new char[WIN_TITLE_MAX_SIZE];
        String strTitle;
        int iFind = -1;
        HWND hWnd = User32.INSTANCE.FindWindow(strClass, null);
        while(hWnd != null) {
            User32.INSTANCE.GetWindowText(hWnd, lpString, WIN_TITLE_MAX_SIZE);
            strTitle = new String(lpString);
            strTitle = strTitle.toUpperCase();
            iFind = strTitle.indexOf(strSearch);
            if(iFind != -1) {
                return hWnd;
            }
            hWnd = User32.INSTANCE.FindWindowEx(null, hWnd, strClass, null);
        }
        return hWnd;
    }
}

  4. And invoke 

    User32.INSTANCE.SetFocus(Win32WindowUtils.GetWindowHandle(windowTitle.toUpperCase(), null);

Of course - windowTitle is your window title (String) that you want to focus.

Upvotes: 3

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