字符串排序

目录
方法1：直接用数组排序
 方法二:用Collections进行排序

方法1：直接用数组排序

public class StringSort {
    public static void main(String[] args) {
        String[] strings = {"abc123", "abc+1234", "ababab--1"};

        // 对每个字符串计算字母字符个数和数字字符个数，并按照字母数字比和字符串本身大小排序
        Arrays.sort(strings, (s1, s2) -> {
            int alphaCount1 = 0, numericCount1 = 0;
            for (char c : s1.toCharArray()) {
                if (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z') alphaCount1++;
                else if (c >= '0' && c <= '9') numericCount1++;
            }
            double ratio1 = numericCount1 == 0 ? Double.MAX_VALUE : (double) alphaCount1 / numericCount1;

            int alphaCount2 = 0, numericCount2 = 0;
            for (char c : s2.toCharArray()) {
                if (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z') alphaCount2++;
                else if (c >= '0' && c <= '9') numericCount2++;
            }
            double ratio2 = numericCount2 == 0 ? Double.MAX_VALUE : (double) alphaCount2 / numericCount2;

            if (ratio1 < ratio2) return 1;
            else if (ratio1 > ratio2) return -1;
            else return s2.compareTo(s1); // 按照降序排列
        });

        // 输出排序后的结果
        System.out.println(Arrays.toString(strings));
    }
}

方法二:用Collections进行排序

import java.util.*;
import java.text.*;

public class Main{

	public static void main(String[] args){
		String[] strings = {"abc123","abc+1234","abcabab--1"};
		HashMap<String,Double> map = new HashMap<>();
		for(int i=0; i<strings.length; i++){
			map.put(strings[i],getFun(strings[i]));
		}
		System.out.println(map);
		Set<String> set = map.keySet();
		ArrayList<String> list = new ArrayList<>();
		
		for(String str:set){
			list.add(str);
		}
		
		Collections.sort(list,(str1,str2)->{
			// return map.get(str1)==map.get(str2) ? str1.compareTo(str2) : map.get(str2) - map.get(str1);
			if(map.get(str1)==map.get(str2)){
				return str1.compareTo(str2);
			}
			
			if(map.get(str2)>map.get(str1)){
				return 1;
			}else{
				return -1;
			}
			
			
		});
		
		System.out.println(list);
	}
	
	public static double getFun(String line){
		int charNum=0;
		int digNum = 0;
		for(int i=0; i<line.length();i++){
			if(line.charAt(i)>='0'&&line.charAt(i)<='9'){
				digNum++;
			}else{
				charNum++;
			}
		}
		return 1.0*charNum/digNum;
	}
}