2

我想创建一个包含这些注释的 midi 文件。我从互联网上获取了这段代码。如果我能找出问题所在，我可以走得更远。当我运行这个应用程序时，我只得到一个错误调用“java result 1”错误。我需要的是在我运行它之后应该有一个生成的 midi 文件，其中包含我通过的注释。完整的代码可用。

public class CreateSequence{
  private static final int VELOCITY = 64;
  public static void main(String[] args) {
    if (args.length != 1) {
        printUsageAndExit();
    }
    File outputFile = new File(args[0]);
    Sequence    sequence = null;
    try {
        sequence = new Sequence(Sequence.PPQ, 1);
    } catch (InvalidMidiDataException e) {
        e.printStackTrace();
        System.exit(1);
    }   
    Track track = sequence.createTrack();

    // first chord: C major
    track.add(createNoteOnEvent(60, 0));
    track.add(createNoteOnEvent(64, 0));
    track.add(createNoteOnEvent(67, 0));
    track.add(createNoteOnEvent(72, 0));
    track.add(createNoteOffEvent(60, 1));
    track.add(createNoteOffEvent(64, 1));
    track.add(createNoteOffEvent(67, 1));
    track.add(createNoteOffEvent(72, 1));

    // second chord: f minor N
    track.add(createNoteOnEvent(53, 1));
    track.add(createNoteOnEvent(65, 1));
    track.add(createNoteOnEvent(68, 1));
    track.add(createNoteOnEvent(73, 1));
    track.add(createNoteOffEvent(63, 2));
    track.add(createNoteOffEvent(65, 2));
    track.add(createNoteOffEvent(68, 2));
    track.add(createNoteOffEvent(73, 2));

    // third chord: C major 6-4
    track.add(createNoteOnEvent(55, 2));
    track.add(createNoteOnEvent(64, 2));
    track.add(createNoteOnEvent(67, 2));
    track.add(createNoteOnEvent(72, 2));
    track.add(createNoteOffEvent(64, 3));
    track.add(createNoteOffEvent(72, 3));

    // forth chord: G major 7
    track.add(createNoteOnEvent(65, 3));
    track.add(createNoteOnEvent(71, 3));
    track.add(createNoteOffEvent(55, 4));
    track.add(createNoteOffEvent(65, 4));
    track.add(createNoteOffEvent(67, 4));
    track.add(createNoteOffEvent(71, 4));

    // fifth chord: C major
    track.add(createNoteOnEvent(48, 4));
    track.add(createNoteOnEvent(64, 4));
    track.add(createNoteOnEvent(67, 4));
    track.add(createNoteOnEvent(72, 4));
    track.add(createNoteOffEvent(48, 8));
    track.add(createNoteOffEvent(64, 8));
    track.add(createNoteOffEvent(67, 8));
    track.add(createNoteOffEvent(72, 8));

    //Now we just save the Sequence to the file we specified.
    //The '0' (second parameter) means saving as SMF type 0.
    //Since we have only one Track, this is actually the only option
    //(type 1 is for multiple tracks).
    try {
        MidiSystem.write(sequence, 0, outputFile);
    } catch (IOException e) {
        e.printStackTrace();
        System.exit(1);
    }
  }

  private static MidiEvent createNoteOnEvent(int nKey, long lTick) {
    return createNoteEvent(ShortMessage.NOTE_ON, nKey, VELOCITY, lTick);
  }

  private static MidiEvent createNoteOffEvent(int nKey, long lTick) {
    return createNoteEvent(ShortMessage.NOTE_OFF, nKey, 0, lTick);
  }

  private static MidiEvent createNoteEvent(int nCommand, int nKey,
                                           int nVelocity, long lTick) {
    ShortMessage message = new ShortMessage();
    try {
        message.setMessage(nCommand, 0, nKey, nVelocity); // 0 always on channel 1
    } catch (InvalidMidiDataException e) {
        e.printStackTrace();
        System.exit(1);
    }
    MidiEvent event = new MidiEvent(message, lTick);
    return event;
  }

  private static void printUsageAndExit(){
        out("usage:");
        out("java CreateSequence <midifile>");
        System.exit(1);
  }

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

这是输出

   usage:
   java CreateSequence <midifile>
   Java Result: 1
4

2 回答 2

1

您需要将输出文件名作为 arg 传递。它以代码 1 退出，因为如果您不使用正确的 arg 计数运行它，它会调用 printUsafeAndExit()。尝试将其运行为：

java CreateSequence output.mid

如果您在传递 args 时遇到问题（如果您使用 Eclipse 之类的 IDE，可能会让初学者感到困惑），只需删除此检查：

if (args.length != 1) {
    printUsageAndExit();
}

并对输出文件进行硬编码：

File outputFile = new File("output.mid");
于 2014-10-31T04:46:44.413 回答
0

你是如何调用这个 Java 程序的？该代码期望在命令行中传递一个参数。查看输出它看起来像方法

private static void printUsageAndExit()
{
    out("usage:");
    out("java CreateSequence <midifile>");
    System.exit(1);
}

正在被调用。您需要在运行程序时将文件名传递（我相信）

于 2014-10-31T04:47:05.343 回答