Java String Manipulation : Comparing adjacent Characters in Java

Question

i have the following problem
Given a string, return a \"cleaned\" string where adjacent chars that are the same have been reduced to a single char. So \"yyzzza\"

Answer 1

public static String stringClean(String str){
    int startIndex = str.indexOf(str);
    char startChar = '\u0000';
    char adjacentChar = '\u0000';
    boolean flag = false; // added
    System.out.println("startIndex-->" + startIndex);
    final StringBuilder sb = new StringBuilder();

    for(startIndex = 0; startIndex < str.length(); startIndex++){
        startChar = str.charAt(startIndex);
        System.out.println("startIndex ::" + startIndex);
        System.out.println("startChar ::" + startChar);

        final int adjacentPosition = startIndex + 1;
        System.out.println("adjacentPosition ::" + adjacentPosition);
        if(adjacentPosition != str.length()){
            adjacentChar = str.charAt(adjacentPosition);
            System.out.println("adjacentChar ::" + adjacentChar);
        } else {
            flag = true;
        }
        if(startChar == adjacentChar){
            System.out.println("startChar ::" + startChar);
            System.out.println("adjacentChar::" + adjacentChar);

            System.out.println("Before Substring string --->" + str);
            str = str.substring(1);
            startIndex--;
            System.out.println("After Substring string --->" + str);
            System.out.println("IndexOf check ---->"
                + sb.toString().indexOf(startChar));
            if(sb.toString().indexOf(startChar) != -1){
                sb.append(adjacentChar);
                System.out.println("Appended String in if part-->"
                    + sb.toString());
            } else if(flag) {                   /* added */
                sb.append(adjacentChar);
            }
        } else{
            str = str.substring(1);
            startIndex--;
            sb.append(startChar);
            System.out.println("Appended String --->" + sb.toString());
        }
    }// end of for loop
    return sb.toString();
}