无法执行命令：无此类文件或目录/ Java

Question

I am trying to run a .jar file via another program. For example, I have a HelloWorld.jar file which opens a dialog saying "Hello World". And I have a Test.jar program. When I do something in the Test.jar (ie click some button), it should run the HelloWorld.jar .

The way I am currently doing so is running a terminal command java -jar HelloWorld.jar using ProcessBuilder . However, I get this error:

Debug: "C:\Users\Asus\.fairplay\data\apps\Amnesia\.tmp524\.bin" exists: true
java.io.IOException: Cannot run program "java -jar Amnesia.jar" (in directory "C:\Users\Asus\.fairplay\data\apps\Amnesia\.tmp524\.bin"): CreateProcess error=2, No such file or directory
    at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
    at me.darksidecode.fairplay.client.util.Utils.execute(Utils.java:74)
    at me.darksidecode.fairplay.client.app.AppLauncher.launch0(AppLauncher.java:61)
    at me.darksidecode.fairplay.client.app.AppLauncher.launch(AppLauncher.java:37)
    at me.darksidecode.fairplay.client.app.AppLoader.downloadAndRun(AppLoader.java:28)
    at me.darksidecode.fairplay.client.gui.frame.GuiLauncher.onPacketReceiving(GuiLauncher.java:165)
    at me.darksidecode.fairplay.client.core.FairPlayClient.lambda$processPacket$1(FairPlayClient.java:120)
    at java.lang.Thread.run(Thread.java:745)
    Caused by: java.io.IOException: CreateProcess error=2, No such file or directory
    at java.lang.ProcessImpl.create(Native Method)
    at java.lang.ProcessImpl.<init>(ProcessImpl.java:386)
    at java.lang.ProcessImpl.start(ProcessImpl.java:137)
    at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
    ... 7 more

I am 100% sure that both the file and the directory exist , and I even checked that. As you can see in the error over here, there is also a debug message proving that.

My code for command execution:

public static Process execute(final String path, final String cmd, final boolean removeJavaOptions) {
    File f = Files.getFile(path);
    System.out.println("Debug: \"" + f.getAbsolutePath() + "\" exists: " + f.exists());

    try {
        final ProcessBuilder pb = new ProcessBuilder(cmd);

        pb.directory(Files.getFile(path));
        pb.redirectErrorStream(true);

        if (removeJavaOptions)
            pb.environment().remove("_JAVA_OPTIONS");
        return pb.start();
    } catch (final Exception ex) {
        ex.printStackTrace();
        return null;
    }
}

The usage of this method itself:

Utils.execute(bin.getAbsolutePath().replace(bin.getName(), ""), "java -jar " + bin.getName(), false);

I have not found any useful answers to this question on StackOverflow or anywhere else yet. Hopefully there is a solution to solve this.

Answer 1

The ProcessBuilder constructor accepts either a List<String> , or a varargs (several strings), eg

new ProcessBuilder( "command", "arg1", "arg2", "arg3" );

Instead of passing it the commands and the arguments separately, you have tried to pass it the command together with the arguments in the same string.

The builder interprets the first argument as the name of the command. Thus, it believes that you are trying to run a file called java -jar Amnesia.jar . It thinks you simply have an executable file with spaces in its name. But of course, the operating system can't find such an executable file.

What you should do is run the command with the arguments separated from the command, that is:

new ProcessBuilder( "java", "-jar", "Amnesia.jar" );

So you'll need to reconstruct your execute method, such that either the cmd parameter is a List<String> , an array ( String[] ), or it is the last parameter and is a varargs parameter.