JAVA EE: How to use appendReplacement and appendTail methods of matcher class

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RegexDemo.java

import java.util.regex.Matcher;

import java.util.regex.Pattern;

/**

 * 

 * The Matcher class provides appendReplacement and appendTail methods for text

 * replacement.

 *

 */

public class RegexDemo

{

    private static String REGEX = "aa";

    private static String INPUT = "aafooaafooaafooaa";

    private static String REPLACE = "-";

    public static void main(String[] args)

    {

        Pattern pattern = Pattern.compile(REGEX);

        Matcher matcher = pattern.matcher(INPUT);

        StringBuffer sb = new StringBuffer();

        while (matcher.find())

        {

            /*

             * Parameters:

             * 

             * sb - The target string buffer 

             * replacement - The replacement string

             * 

             * Returns: This matcher

             * 

             */

            matcher.appendReplacement(sb, REPLACE);

        }

        matcher.appendTail(sb);

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

    }

}