What you said above is correct. The key is to remove the numbers in front of the string. Maybe you are not familiar with regular expressions at the moment, so I will write a simple method to remove the numbers in front of the string:

import java.util.*;

public class Main {

    // 取出字符串前面的数字
    public static String getStartDigits(String str) {
        int len = str.length();
        int stopPos = 0;
        for (int i = 0; i < len; i++) { // 遍历 str 的字符
            char ch = str.charAt(i);
            if (!(ch >= '0' && ch <= '9')) { // 如果当前字符不是数字
                stopPos = i;
                break;
            }
        }
        return str.substring(0, stopPos);
    }

    public static void sortByStartDigits(List<String> list) {
        Collections.sort(list, new Comparator<String>() {
            @Override
            public int compare(String s1, String s2) {
                int num1 = Integer.parseInt(getStartDigits(s1));
                int num2 = Integer.parseInt(getStartDigits(s2));

                return num1 - num2;
            }
        });
    }

    public static void main(String[] args) throws Exception {
        List<String> list = Arrays.asList(
                "1号摄像机", "10号摄像机", "2号摄像机", "20号摄像机", "30号摄像机", "31号摄像机");
        System.out.println("排序前：");
        System.out.println(list);
        
        sortByStartDigits(list);
        System.out.println("排序后：");
        System.out.println(list);
    }

}

Just customize oneComparator.

    String[] arr = {"1号","2号","3号","11号","21号","12号","13号","100号"};
    Arrays.sort(arr);
    System.out.println(Arrays.toString(arr));
    List<String> list = Arrays.asList(arr);
    Collections.sort(list,new Comparator<String>() {
        @Override
        public int compare(String o1, String o2) {
            return Integer.parseInt(o1.replaceAll("[^0-9]*", "")) - Integer.parseInt(o2.replaceAll("[^0-9]*", ""));
        }
    });
    System.out.println(list);