java正则表达式-取前一个相同的串

str.replaceAll(“(.)\\1+”, “$1”)

public static void demo()
    {
        String str = new String("我我...我我...我要..要要...要要...学学学....学学...编编编...编程..程.程程...程...程");

        str = str.replaceAll("\\.+", "");
        System.out.println(str);
        str = str.replaceAll("(.)\\1+", "$1");
        System.out.println(str);
    }