Java：在字符串中打印唯一字符

根据所需的输出，当以后重复时，必须替换最初已经添加的字符，因此：

public static void uniqueCharacters(String test){    String temp = "";    for (int i = 0; i < test.length(); i++){        char current = test.charAt(i);        if (temp.indexOf(current) < 0){ temp = temp + current;        } else { temp = temp.replace(String.valueOf(current), "");        }    }    System.out.println(temp + " ");}