public static String collapseNewlines(String argStr){
  char last=argStr.charAt(0);
  StringBuffer argBuf=new StringBuffer();
  for (int cIdx=0; cIdx < argStr.length(); cIdx++) {
    char ch=argStr.charAt(cIdx);
    if (ch != '\n' || last != '\n') {
      argBuf.append(ch);
      last=ch;
    }
  }
  return argBuf.toString();
}

public static String collapseNewlines ( String argStr ) { char last = argStr . charAt ( 0 ) ; StringBuffer argBuf = new StringBuffer ( ) ; for ( int cIdx = 0 ; cIdx < argStr . length ( ) ; cIdx ++ ) { char ch = argStr . charAt ( cIdx ) ; if ( ch != '\n' || last != '\n' ) { argBuf . append ( ch ) ; last = ch ; } } return argBuf . toString ( ) ; }
remove / collapse multiple newline characters .
