java 正则 连续数字_Java - 正则表达式匹配字符串中的连续数字或字符

下面是一个快速，肮脏，未优化(可能是越野车)，但你想要实现什么样的独立示例。

public static void main(String[] args) {

// should not allow

System.out.println(hasValidSequence("abcd", 3));

// should not allow

System.out.println(hasValidSequence("1234", 3));

// should allow

System.out.println(hasValidSequence("abcd", 4));

// should allow

System.out.println(hasValidSequence("1234", 4));

}

public static boolean hasValidSequence(String input, int maxAllowed) {

// boilerplate validation of empties/nulls

if (input == null || input.isEmpty()) {

// TODO handle better?

return false;

}

// counter for blowing things up if reached

int counter = 0;

// char takes int values - initializing as bogus 0

char c = (char)0;

// iterating input String characters one by one

for (int i = 0; i < input.length(); i++) {

// previous char is next char as int, - 1 --> they're successive

// you can fool around and replace with input.charAt(i) <= i

// for indirect sequences or same characters

// TODO check it's an alpha numeric!

if (c == input.charAt(i) - 1) {

// incrementing counter

counter++;

}

// assigning current char

c = input.charAt(i);

// counter reached? we blow things up!

if (counter == maxAllowed) {

return false;

}

}

// no counter reached, return true

return true;

}

输出

false

false

true

true