Problem bei Aufruf einer Funktion

[Devilmarkus]

Hello,

please, can someone explain me, how I can call a non-static routine from a static one?

My problem is:
I want to call from jemu.ui.JEMU.java a routine in jemu.system.cpc.CPCDiscImage.java.

JEMU.java:

............
import jemu.system.cpc.CPCDiscImage.java
............
protected void UserSave(){
CPCDiscImage.UserSave();
}
............

CPCDiscImage.java:

............
    public synchronized void UserSave() {
   // choose destination file
    final JFileChooser fc = new JFileChooser();
    fc.setDialogTitle("Select destination dsk file...");
    int result = fc.showSaveDialog(null);
    final String newFileName = fc.getSelectedFile().getAbsolutePath();
    
    // create file name '_saved'
     File discImage = new File(newFileName);
    String saveFileName = discImage.getName();
     File savedImage = new File(discImage.getParent(), saveFileName);
    if (System.getSecurityManager() != null) {
      try {
        System.getSecurityManager().checkWrite(savedImage.getAbsolutePath());
      } catch ( SecurityException sex) {
        // son't save
        return;
      }
    }

    System.out.println("store dsk file to " + savedImage);
    name = savedImage.getAbsolutePath();

    // save data to file
    try {
       BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(savedImage));
      // disc information block
      bos.write(EXTENDED_DESCRIPTION.getBytes(ENCODING));
      bos.write(CREATOR_DATA.getBytes(ENCODING));
      bos.write(numberOfTracks);
      bos.write(numberOfSides);
      bos.write(0);
      bos.write(0);

      // track size table
      for (int track = 0; track < numberOfTracks; track++) {
        for (int side = 0; side < numberOfSides; side++) {
           int trackLength = tracks[track][side].getLength();
          bos.write((trackLength / 256) & 0xFF);
        }
      }
      int unused = 0x100 - 0x34 - numberOfTracks * numberOfSides;
      for (int i = 0; i < unused; i++) {
        bos.write(0);
      }

      // track data
      for (int track = 0; track < numberOfTracks; track++) {
        for (int side = 0; side < numberOfSides; side++) {
           CPCDiscImageTrack td = tracks[track][side];
          // track information block
          bos.write(TRACK_INFO.getBytes(ENCODING));
          bos.write(0); // track info end
          bos.write(0); // unused
          bos.write(0); // unused
          bos.write(0); // unused
          bos.write(td.getTrack());
          bos.write(td.getSide());
          bos.write(0); // unused
          bos.write(0); // unused
          bos.write(td.getSector(0).getSize()); // UPD765A size
           int numberOfSectors = td.getSectorCount();
          bos.write(numberOfSectors);
          bos.write(0x4e); // GAP#3 length
          bos.write(0xe5); // filler byte

          // sector information list
          for (int sector = 0; sector < numberOfSectors; sector++) {
             CPCDiscImageSector sd = td.getSector(sector);
            bos.write(sd.getTrack());
            bos.write(sd.getSide());
            bos.write(sd.getId());
            bos.write(sd.getSize()); // UPD765A size
            bos.write(0); // FDC status register 1
            bos.write(0); // FDC status register 2
             int dataSize = sd.getData().length;
            bos.write(dataSize & 0xFF);
            bos.write((dataSize / 256) & 0xFF);
            // System.out.println("sec " + sd.getTrack() + "/" + sd.getSide() + "/" + sd.getId() + "/"
            // + UPD765A.getCommandSize(sd.getSize()) + " size=" + sd.getData().length);
            // System.out.println(" -> " + (dataSize & 0xFF) + " / " + ((dataSize / 256) & 0xFF));
          }
          unused = 0x100 - 0x18 - 8 * numberOfSectors;
          for (int i = 0; i < unused; i++) {
            bos.write(0);
          }
          for (int sector = 0; sector < numberOfSectors; sector++) {
            bos.write(td.getSector(sector).getData());
          }
        }
      }
      bos.close();

    } catch ( IOException iox) {
      System.out.println("can't write to file " + savedImage + ": " + iox.getMessage());
    }
  }
...........

Problem:

jemu\ui\JEMU.java:1160: non-static method UserSave() cannot be referenced from a static context

It would be great, if somebody can help me...
Cheers, Markus

 

[Devilmarkus]

I also tried to make UserSave() in CPCDiscImage.java static, but then the whole emulator hungs up...


You can see the full emulator here in action:
http://cpc.devilmarkus.de/include.php?path=content/content.php&contentid=46

For getting the full source code, please ask me...

Cheers, Markus

 

[Wildcard]

You cannot just call a regular method from a static context. You want to invoke an object's method, so you need a reference to that object. How else could be determined to which instance of the class you're referning to?

 

[Devilmarkus]

You cannot just call a regular method from a static context. You want to invoke an object's method, so you need a reference to that object. How else could be determined to which instance of the class you're referning to?

I don't know. I am a noob in JAVA. The problem is, that I want to call this function, if a user clicks on a button.

The function lets the user save a disc-image to his pc.