Java - Generating strings of length x

Question

I have some 'heavy' string manipulation in my Java program, which often involves iterating through a String and replacing certain segments with filler characters, usually "@". These are characters are later removed but are used so that the length of the String and the current index are kept intact during the iteration.

This process usually involves replacing more than 1 character at a time.
e.g.
I might need to replace "cat" with "@@@" in the string "I love cats", giving "I love @@@s", So often I need to create strings of "@" with x length.

In python, this is easy.

NewString = "@" *x

In Java, I find my current method revolting.

String NewString = "";
for (int i=0; i< x; i++)  {  
    NewString = NewString.concat("@");  }

Is there a proper, pre-established method for doing this?
Does anybody have a shorter, more 'golfed' method?
Thanks!

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Specs:
Java SE (Jre7)
Windows 7 (32)

Answer 1

It's not clear to me what kind of regex the comments are suggesting, but creating a string filled with a particular character to the given length is pretty easy:

public static String createString(char character, int length) {
    char[] chars = new char[length];
    Arrays.fill(chars, character);
    return new String(chars);
}

Answer 2

Guava has a nice little method Strings.repeat(String, int). Looking at the source of that method, it basically amounts to this:

StringBuilder builder = new StringBuilder(string.length() * count);
for (int i = 0; i < count; i++) {
  builder.append(string);
}
return builder.toString();