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class ShowHeapError {
    private Vector<String> names = new Vector<String>();
    private final InputStreamReader input;
    private final BufferedReader reader;

    public ShowHeapError(String filename) throws IOException {
        this.input = new FileReader(filename);
        this.reader = new BufferedReader(input);
    }

    public void addNames() throws IOException {
        String newName;
        while (((newName = reader.readLine()) != null) &&
               (newName.equalsIgnoreCase("quit") == false)) {
            names.addElement(newName);
            System.out.println("adding " + newName);
        }
        input.close();
    }

    public static void main(String[] args) throws IOException {
    if    if (args.length != 1) {
            System.out.println("Arguments: [filename]");
            return;
        }
        ShowHeapError demo = new ShowHeapError(args[0]);
        demo.addNames();
    }
}

class ShowHeapError {
    // ... other methods

    static public String readLimitedLine(Reader reader, int limit) throws IOException {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < limit; i++) {
            int c = reader.read();
            if (c == -1) {
                return nullreturn null;
            }
            if (((char) c == '\n') || ((char) c == '\r')) {
                break;
            }
            sb.append((char) c);
        }
        return sb.toString();
    }

    static public final int lineLengthLimit = 1024;
    static public final int lineCountLimit = 1000000;

    public void addNames() throws IOException {
        String newName;
        for (int i = 0; i < lineCountLimit; i++) {
            newName = readLimitedLine( reader, lineLengthLimit);
            if (newName == null) {
         null) {
        break;
            }
            if (newName.equalsIgnoreCase("quit")) {
                break;
            }

            names.addElement(newName);
            System.out.println("adding " + newName);
        }
        input.close();
    }

}

class ShowHeapError {
    // ...other methods
    static public final int fileSizeLimit = 1000000;

    public ShowHeapError(String filename) throws IOException {
        if (Files.size( Paths.get( filename)) > fileSizeLimit) {
            throw new IOException("File too large");
        }
        this.input = new FileReader(filename);
        this.reader = new BufferedReader(input);
    }
}

/** Assuming the heap size as 512 MB (calculated as 1/4th of 2 GB RAM = 512 MB)
 *  Considering long values being entered (64 bits each, the max number of elements
 *  would be 512 MB/64bits = 67108864)
 */
public class ShowHeapError {
   Vector<Long> names = new Vector<Long>(); // Accepts unknown number of records
   long newID = 0L;
   int count = 67108865;
   int i = 0;
   InputStreamReader input = new InputStreamReader(System.in);
   Scanner reader = new Scanner(input);

   public void addNames() {
     do {
       // Adding unknown number of records to a list
       // The user can enter more IDs than the heap can support and thus 
       // exhaust the heap. Assume that the record ID is a 64 bit long value
      
       System.out.print("Enter recordID (To quit, enter -1): ");
       newID = reader.nextLong();
       
       names.addElement(newID);
       i++;
    } }while (i < count || newID != -1);
     // Close "reader" and "input"
   }

   public static void main(String[] args) {
     ShowHeapError demo = new ShowHeapError();
     demo.addNames();
   }
}

   // ...
   int count = 10000000;
   // ...