Unnecessary array copy in AbstractStringBuilder.indexOf(String)? (original) (raw)

Martin Desruisseaux martin.desruisseaux at geomatys.fr
Mon Nov 19 15:46:58 UTC 2012

Hello all

I noticed that AbstractStringBuilder.indexOf(String, int) is implemented as below:

 public int indexOf(String str, int fromIndex) {
     return String.indexOf(value, 0, count,
                           str.toCharArray(), 0, str.length(),

fromIndex); }

The call to str.toCharArray() creates a copy of the String.value char[] array. This copy doesn't seem necessary since the above String.indexOf(...) method doesn't modify the array content. Shouldn't AbstractStringBuilder passes directly the reference to the String internal array instead, maybe using package-privated access to the array?

Admittedly the cloned array is usually small, but the call to indexOf(String, int) is often done in a loop.

 Martin

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