当前平台不支持Desktop API

Question

我遇到过这个错误:

Desktop.getDesktop().open(new File(report.html"));

我会从我的java应用程序中打开一个文件.我用这个方法:

Desktop.getDesktop().open(new File(report.html"));

我怎么解决这个问题？

Answer 1

基本上,问题是Java Desktop集成在Linux上不能很好地工作.

它旨在与Windows一起工作; 某些东西适用于其他系统,但没有人真正关心为这些系统添加适当的支持.即使您安装了所需的"gnome库",结果也会很差.

我刚才遇到了同样的问题,并提出了下面的课程.

通过使用特定于系统的命令实现目标:

KDE:     kde-open
GNOME:   gnome-open
Any X-server system: xdg-open
MAC:     open
Windows: explorer

如果这些都不起作用,它会尝试Java Desktop提供的实现.
因为这个通常会失败,所以它是最后的尝试.

DesktopApi类

这个类提供静态方法open,browse和edit.
它经过测试可在Linux(Kde和Gnome),Windows和Mac上运行.

如果您使用它,请给我信用.

package net.mightypork.rpack.utils;

import java.awt.Desktop;
import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.util.ArrayList;
import java.util.List;


public class DesktopApi {

    public static boolean browse(URI uri) {

        if (openSystemSpecific(uri.toString())) return true;

        if (browseDESKTOP(uri)) return true;

        return false;
    }


    public static boolean open(File file) {

        if (openSystemSpecific(file.getPath())) return true;

        if (openDESKTOP(file)) return true;

        return false;
    }


    public static boolean edit(File file) {

        // you can try something like
        // runCommand("gimp", "%s", file.getPath())
        // based on user preferences.

        if (openSystemSpecific(file.getPath())) return true;

        if (editDESKTOP(file)) return true;

        return false;
    }


    private static boolean openSystemSpecific(String what) {

        EnumOS os = getOs();

        if (os.isLinux()) {
            if (runCommand("kde-open", "%s", what)) return true;
            if (runCommand("gnome-open", "%s", what)) return true;
            if (runCommand("xdg-open", "%s", what)) return true;
        }

        if (os.isMac()) {
            if (runCommand("open", "%s", what)) return true;
        }

        if (os.isWindows()) {
            if (runCommand("explorer", "%s", what)) return true;
        }

        return false;
    }


    private static boolean browseDESKTOP(URI uri) {

        logOut("Trying to use Desktop.getDesktop().browse() with " + uri.toString());
        try {
            if (!Desktop.isDesktopSupported()) {
                logErr("Platform is not supported.");
                return false;
            }

            if (!Desktop.getDesktop().isSupported(Desktop.Action.BROWSE)) {
                logErr("BROWSE is not supported.");
                return false;
            }

            Desktop.getDesktop().browse(uri);

            return true;
        } catch (Throwable t) {
            logErr("Error using desktop browse.", t);
            return false;
        }
    }


    private static boolean openDESKTOP(File file) {

        logOut("Trying to use Desktop.getDesktop().open() with " + file.toString());
        try {
            if (!Desktop.isDesktopSupported()) {
                logErr("Platform is not supported.");
                return false;
            }

            if (!Desktop.getDesktop().isSupported(Desktop.Action.OPEN)) {
                logErr("OPEN is not supported.");
                return false;
            }

            Desktop.getDesktop().open(file);

            return true;
        } catch (Throwable t) {
            logErr("Error using desktop open.", t);
            return false;
        }
    }


    private static boolean editDESKTOP(File file) {

        logOut("Trying to use Desktop.getDesktop().edit() with " + file);
        try {
            if (!Desktop.isDesktopSupported()) {
                logErr("Platform is not supported.");
                return false;
            }

            if (!Desktop.getDesktop().isSupported(Desktop.Action.EDIT)) {
                logErr("EDIT is not supported.");
                return false;
            }

            Desktop.getDesktop().edit(file);

            return true;
        } catch (Throwable t) {
            logErr("Error using desktop edit.", t);
            return false;
        }
    }


    private static boolean runCommand(String command, String args, String file) {

        logOut("Trying to exec:\n   cmd = " + command + "\n   args = " + args + "\n   %s = " + file);

        String[] parts = prepareCommand(command, args, file);

        try {
            Process p = Runtime.getRuntime().exec(parts);
            if (p == null) return false;

            try {
                int retval = p.exitValue();
                if (retval == 0) {
                    logErr("Process ended immediately.");
                    return false;
                } else {
                    logErr("Process crashed.");
                    return false;
                }
            } catch (IllegalThreadStateException itse) {
                logErr("Process is running.");
                return true;
            }
        } catch (IOException e) {
            logErr("Error running command.", e);
            return false;
        }
    }


    private static String[] prepareCommand(String command, String args, String file) {

        List<String> parts = new ArrayList<String>();
        parts.add(command);

        if (args != null) {
            for (String s : args.split(" ")) {
                s = String.format(s, file); // put in the filename thing

                parts.add(s.trim());
            }
        }

        return parts.toArray(new String[parts.size()]);
    }

    private static void logErr(String msg, Throwable t) {
        System.err.println(msg);
        t.printStackTrace();
    }

    private static void logErr(String msg) {
        System.err.println(msg);
    }

    private static void logOut(String msg) {
        System.out.println(msg);
    }

    public static enum EnumOS {
        linux, macos, solaris, unknown, windows;

        public boolean isLinux() {

            return this == linux || this == solaris;
        }


        public boolean isMac() {

            return this == macos;
        }


        public boolean isWindows() {

            return this == windows;
        }
    }


    public static EnumOS getOs() {

        String s = System.getProperty("os.name").toLowerCase();

        if (s.contains("win")) {
            return EnumOS.windows;
        }

        if (s.contains("mac")) {
            return EnumOS.macos;
        }

        if (s.contains("solaris")) {
            return EnumOS.solaris;
        }

        if (s.contains("sunos")) {
            return EnumOS.solaris;
        }

        if (s.contains("linux")) {
            return EnumOS.linux;
        }

        if (s.contains("unix")) {
            return EnumOS.linux;
        } else {
            return EnumOS.unknown;
        }
    }
}

Answer 2

我正在使用Ubuntu 12.04 LTS 64位与Oracle jdk1.6.0_45,并遇到了同样的问题.我正在运行gnome-classic作为桌面而不是Unity.这对我有用:

sudo apt-get install libgnome2-0

安装此软件包后,我重新启动了我的Java Swing应用程序并且Desktop.getDesktop().open(new File("myfile"));运行正常.

Answer 3

并非所有系统都支持Desktop类.

从Java Swing教程如何与桌面类集成:

使用isDesktopSupported()方法确定Desktop API是否可用.在Solaris操作系统和Linux平台上,此API依赖于Gnome库.如果这些库不可用,则此方法将返回false.在确定支持Desktop API之后,即isDesktopSupported()返回true,应用程序可以使用静态方法getDesktop()检索Desktop实例.

在任何情况下,如果不支持Desktop,最好提供另一种打开文件的方法.