Can you simulate String.replace(...) & String.contains(...)

[Majid Al-Fifi]

Hi All,

As you know jdk1.5 String class provides
*** replace(String,String) and
*** contains(String)

I have developed an app that uses those methods to discover that I need to compile my app using jdk1.4 because of some restrictions on the production environment.

I am thinking of making MyStringUtil.java
and make the method as follows:

public static String replace(String str, String s1, String s2)
{
//find all s1's in str and replace them with s2's
//return str
}

Does anyone have code for an algorithm that does their job exactly.
Is there a better alternative?

Thanks..
Majid
[ August 29, 2006: Message edited by: Majid Al-Fifi ]

[James Sabre]

*** replace(String,String)

You could write a regular expression and use String.replaceFirst()

*** contains(String)

and again you could write a regular expression and use String.matches() .

The detail of the regular expressions to use depends on the characters to be replaced/matched.

[Alan Moore]

For the contains() method, I would just do it the way Sun did:

public static boolean contains(String str1, String str2)
{
  return str1.indexOf(str2) != -1;
}

(That method has always seemed like a waste of space to me.) As for replace(), I would use replaceAll() behind the scenes:

public static String replace(String target, String str1, String str2)
{
  String str1a = str1.replaceAll("\\p{Punct}", "\\\\$0");
  String srt2a = str2.replaceAll("[$\\\\]", "\\\\$0");
  return target.replaceAll(str1a, str2a);
}

Having to pre-process the strings seems inefficient, but (for longer target strings, at least) that will be offset by the fact that the regex package will use a Boyer-Moore algorithm to do the searching.

[Majid Al-Fifi]

Thanks guys,

I have used used the two methods Alan provided and everything is fine.