CODEWITHSUNDEEP
java
new
new

Reputation: 1

I want to save an Arraylist of objects into a file.Can Someone help me with this?

public void savemap (File file)
      { 
        if (file == null) {         
          if (chooser == null) chooser = createChooser();
          chooser.setDialogType(JFileChooser.SAVE_DIALOG);
          int r = chooser.showDialog(this, null);
          if (r != JFileChooser.APPROVE_OPTION) return;
          file = chooser.getSelectedFile();
        }                           /* get the selected file */
        try {                       /* save the current TSP */
          FileWriter writer = new FileWriter(file);
          writer.write();
          writer.close(); }
        catch (IOException e) {
          String msg = e.getMessage();
          this.stat.setText(msg); System.err.println(msg);
          JOptionPane.showMessageDialog(this, msg,
            "Error", JOptionPane.ERROR_MESSAGE);
        }                           /* set the status text */
        this.curr = file;           /* note the new file name */
      }

Edited

 try {
            int rows = 50;
            int columns = 50;
            Cell [][] cellArray = new Cell[columns][rows];

            FileOutputStream fout = new FileOutputStream(FILE_PATH);
            ObjectOutputStream oos = new ObjectOutputStream(fout);
            oos.writeObject(cellArray);
        }

//This is what i changed the code. Is it correct? However i have an error at (FILE_PATH) FILE_PATH cannot be resolved to a variable

Upvotes: 0

Views: 153

Answers (1)

drew moore
drew moore

Reputation: 32670

To elaborate on my comment: When you call writer.write( ), it expects you to give it a parameter that tells it what to write. Without that parameter, your code should not be compiling. 

String s = "foobar"
writer.write(s)

or just: 

writer.write("foobar")

will write a String value to file.

A second problem you have is that FileWriter (or more accurately, Writer, which it derives from) is only capable of writing Strings, chars and ints by itself. If you want to write arbitrary Objects to file, you'll need to use an ObjectOutputStream: 

RandomObject rando = new RandomObject(); 
FileOutputStream fout = new FileOutputStream(FILE_PATH);
ObjectOutputStream oos = new ObjectOutputStream(fout);
oos.writeObject(rando);

You might find this tutorial useful.

Upvotes: 2

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