java 正则表达式 基于java中正则操作的方法总结

class Demo {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        //获取输入
        System.out.print("Please Enter:");
        String str = sc.nextLine();
        check(str);
    }

    private static void check(String str) {
        //匹配第一位是1-9,第二位及以后0-9（个数在4-10之间）
        String regex = "[1-9][0-9]{4,10}";

        /*
        //匹配单个字符是大小写的a-z
        String regex = "[a-zA-Z]";
        //匹配数字，注意转义字符
        String regex = "\\d";
        //匹配非数字
        String regex = "\\D";
        */

        if(str.matches(regex)) {
            System.out.println("匹配成功");
        } else {
            System.out.println("匹配失败");
        }
    }
}

class Demo {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Please Enter:");
        String str = sc.nextLine();
        split(str);
    }

    private static void split(String str) {
        //匹配一个或多个空格
        String regex = " +";

        String[] arr = str.split(regex);

        for (String s : arr) {
            System.out.println(s);
        }
    }
}

class Demo {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Please Enter:");
        String str = sc.nextLine();
        replace(str);
    }

    private static void replace(String str) {
        //匹配叠词
        String regex = "(.)\\1+";
        String s = str.replaceAll(regex, "*");
        System.out.println(s);
    }
}