Java-将变量从用户输入传递到另一个Java文件

我是Java新手，我有一个项目要做，所以我有一个Java文件，用户必须从目录中的文件列表中进行选择。来自用户的输入保存在变量（文件名）中。我想在另一个java文件中使用该变量来执行其他工作。我在网上搜索，但没有找到适合我的解决方案。也许我做错了什么

第一个文件的代码：

public class Director {

private static void copyFileUsingStream(File source, File dest) throws IOException {
InputStream is = null;
OutputStream os = null;
try {
    is = new FileInputStream(source);
    os = new FileOutputStream(dest);
    byte[] buffer = new byte[1024];
    int length;
    while ((length = is.read(buffer)) > 0) {
        os.write(buffer, 0, length);
    }
} finally {
    is.close();
    os.close();
}
}

public static void main(String[] args) throws IOException {
    
    

    // Creates an array in which we will store the names of files and directories
    String[] pathnames;

    // Creates a new File instance by converting the given pathname string
    // into an abstract pathname
    File f = new File("C:\\Users\\miltos\\Desktop\\polimesa\\available_videos");

    // Populates the array with names of files and directories
    pathnames = f.list();
    System.out.println("Files in the directory:");
    // For each pathname in the pathnames array
    for (String pathname : pathnames) {
        // Print the names of files and directories
        System.out.println(pathname);
    }
    
    Scanner myObj = new Scanner(System.in);  // Create a Scanner object
    System.out.println("Enter file name");
    String fileName = myObj.nextLine();
    File source = new File("C:\\Users\\miltos\\Desktop\\polimesa\\available_videos\\" + fileName);
    File dest = new File("C:\\Users\\miltos\\Desktop\\polimesa\\raw_videos\\" + fileName);
    copyFileUsingStream(source, dest);


}


}

我要使用输入的第二个文件的代码：

 public class TestFFMpeg {

static Logger log = LogManager.getLogger(TestFFMpeg.class);



public static void main(String[] args) {
    
    
    FFmpeg ffmpeg = null;
    FFprobe ffprobe = null;
    

    
    try {
        log.debug("Initialising FFMpegClient");
        ffmpeg = new FFmpeg("C:\\Users\\miltos\\ffmpeg\\bin\\ffmpeg.exe");
        ffprobe = new FFprobe("C:\\Users\\miltos\\ffmpeg\\bin\\ffprobe.exe");
    } catch (IOException e) {
        e.printStackTrace();
    }

    log.debug("Creating the transcoding");
    FFmpegBuilder builder = new FFmpegBuilder()
            .setInput("C:\\Users\\miltos\\Desktop\\polimesa\\raw_videos\\" + filename) //updated
            .addOutput("C:\\Users\\miltos\\Desktop\\polimesa\\videos\\" + filename) //updated
            .setVideoBitRate(200000) 
            .done();
      log.debug("Creating the executor");
    FFmpegExecutor executor = new FFmpegExecutor(ffmpeg, ffprobe);

    log.debug("Starting the transcoding");
    // Run a one-pass encode
    executor.createJob(builder).run();
    log.debug("Transcoding finished");
}


}

---

我还在第二类中创建了一个变量名filename，您将从第一类传递它，同时创建第二类的对象，如

TestFFMpeg obj = new TestFFMpeg();
obj.methodInSecondClass(filename);

二等舱：

    public class TestFFMpeg {
    
    static Logger log = LogManager.getLogger(TestFFMpeg.class);
    
    public void methodInSecondClass(String filename){

    FFmpeg ffmpeg = null;
        FFprobe ffprobe = null;
        
    
        
        try {
            log.debug("Initialising FFMpegClient");
            ffmpeg = new FFmpeg("C:\\Users\\miltos\\ffmpeg\\bin\\ffmpeg.exe");
            ffprobe = new FFprobe("C:\\Users\\miltos\\ffmpeg\\bin\\ffprobe.exe");
        } catch (IOException e) {
            e.printStackTrace();
        }
    
        log.debug("Creating the transcoding");
        FFmpegBuilder builder = new FFmpegBuilder()
                .setInput("C:\\Users\\miltos\\Desktop\\polimesa\\available_videos\\"+filename) //this is where i want the same variable
                .addOutput("C:\\Users\\miltos\\Desktop\\polimesa\\videos\\"+filename) //this is where i want the same variable
                .setVideoBitRate(200000) 
                .done();
          log.debug("Creating the executor");
        FFmpegExecutor executor = new FFmpegExecutor(ffmpeg, ffprobe);
    
        log.debug("Starting the transcoding");
        // Run a one-pass encode
        executor.createJob(builder).run();
        log.debug("Transcoding finished");
    }
    
}

---

你可以在第二类中创建一个构造函数，在第二类中，你可以将文件名作为参数传递。我有个问题要问，你什么时候必须在第一类中传递文件名参数？请指定位置好吗？@harmandepsingkalsi我想在ffmpeg生成器的输入（和输出）中传递filename变量。我看到你的密码了。我把“TestFFMpeg obj=newtestffmpeg（filename）；”放在哪里？在班级的声明之上？当我将您编写的其他代码放在类的声明下时，我得到了关于变量filenameNo的错误，您应该在类1中编写它：TestFFMpeg obj=newtestffmpeg（filename）；因为你有第一类的文件名，对吗？我认为应该在复制文件之前写。在此之前：copyFileUsingStream（源、目标）；我更新了错误代码。谢谢！现在我在第二个类中遇到了一个错误，我将变量filename作为输入和输出（我更新了这些部分的代码）。错误是：无法对非静态方法进行静态引用。代码中有一个小的更新。setInput（“C:\\Users\\miltos\\Desktop\\polimesa\\available\U videos\\”+文件名）。addOutput（“C:\\Users\\miltos\\Desktop\\polimesa\\videos\\”+文件名）。请更新