Some characters not displayed on the Eclipse console with println()

I came across a strange problem recently. I am using StringBuffer to create a string and when I added some white spaces to the string, I realized that some characters were gone.

An example:

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

    StringBuffer sb = new StringBuffer();

    sb.append("000.00                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             ");
    sb.append(filler(800));
    sb.append(filler(800));
    sb.append(filler(800));
    sb.append(filler(800));
    sb.append(filler(800));

    System.out.println(sb.toString());
    System.out.println(sb.toString().charAt(4));

}

public static String filler(Integer size) {
    return String.join("", Collections.nCopies(size, " "));
}

Output running in Eclipse:

000.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
0

filler is a function to create blank strings.

When I run that, the last two zeros of my initial string simple disappears. The curious is that if I print the value of the position in those positions, the zero appears.

Is that some kind of bug on StringBuffer class?

Solution

It is a rendering problem probably specific to your IDE as you output a String with a relative important number of characters.

If I run your program on Eclipse I see indeed an unexpected output :

000.

While I expected 000.00 as beginning of the line.

But if I copy the beginning of the line produced in the Eclipse console and I paste it somewhere else, I see the expected output :

000.00

Make a substring of the StringBuilder and you could see an accurate visible output :

System.out.println(sb.substring(0,6));

For information the problem occurs only at the last append() :

    sb.append(filler(800));
    sb.append(filler(800));
    sb.append(filler(800));
    sb.append(filler(800));
    sb.append(filler(800)); // issue in the output from there

Note that you can force in the Eclipse preferences the maximum character width. It will cause a wrap line at each time the maximum character width is reached for a line.

For example with this setting I can see now the output as expected :

000.00

But as side effect, I would have a breakline in the output at each time my line exceeds the fixed limit.