replace string, what is faster

Hi
in an application I use string replace method to replace some substring as follow:
myString.replaceAll("k5m6m7k4m3","");
The strings are sometime very long.
My question, is the replaceAll the best way and fast enough, or is there another way to do it?
regards

Premature optimization makes kittens cry.

Quote:

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Originally Posted by henry123

Hi
in an application I use string replace method to replace some substring as follow:
myString.replaceAll("k5m6m7k4m3","");
The strings are sometime very long.
My question, is the replaceAll the best way and fast enough, or is there another way to do it?
regards

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It's certainly the easiest. Is it unacceptably slow for your purposes?

Quote:

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Originally Posted by NRitH

Is it unacceptably slow for your purposes?

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I can not say, if it is slow, because I see no other posbility to avoid it!! But as I said the strings are big and long. They are actually text files and somethimes could be few MBs big. I dont know other possibility to replaceAll in JAVA?

If you don't want to bother with StringBuffer you can use org.apache.commons.lang.StringUtils

And also you can use regular expression to match the replacement.

replaceAll() is using a regex. You could try replace() since no regex is involved in the example you gave.

An illustration of the problem would be good. For instance showing the slowness to be with the replace operation rather than IO.

Something like this.

Code:

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String.replaceAll("it(?! this)", "it is ball")

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Quote:

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Originally Posted by henry123

I can not say, if it is slow, because I see no other posbility to avoid it!! But as I said the strings are big and long. They are actually text files and somethimes could be few MBs big. I dont know other possibility to replaceAll in JAVA?

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I wouldn't read the whole thing in in the first place.
Read a line, do a replaceAll(), write the line.
Repeat til end of file.

the problem is not the method replaceAll but using a string when other types are more appropriate, in this case the appropriate type could be a StringBuffer.

That's true. But OP asking more relevant to the replaceAll() method, is there any alternatives to use, isn't it ...

But there's nothing to indicate a StringBuffer would help is there?
We don't know what the OP is doing with the transformed text yet...

I agreed with you. And that's why I suggest to give a try with direct regex in replaceAll().