Java中的随机数生成案例从范围字符串到动态区间应用

import java.util.Random;
public class BasicRandomExample {
    public static void main(String[] args) {
        Random random = new Random();
        // 生成0-99的随机数
        int num1 = random.nextInt(100);
        // 生成10-30的随机数
        int num2 = random.nextInt(21) + 10;
        System.out.println("0-99随机数: " + num1);
        System.out.println("10-30随机数: " + num2);
    }
}

import java.util.Random;
public class RandomCentGenerator {
    public static void main(String[] args) {
        String range = "0.1-0.3";
        int randomCent = getRandomCentInRange(range);
        System.out.println("随机数（分）: " + randomCent);
    }
    public static int getRandomCentInRange(String range) {
        // 1. 分割字符串获取最小值和最大值
        String[] parts = range.split("-");
        if (parts.length != 2) {
            throw new IllegalArgumentException("无效的范围格式，请使用'min-max'格式");
        }
        try {
            // 2. 解析为元并转换为分
            double minYuan = Double.parseDouble(parts[0]);
            double maxYuan = Double.parseDouble(parts[1]);
            int minCent = (int) Math.round(minYuan * 100);
            int maxCent = (int) Math.round(maxYuan * 100);
            // 3. 确保min <= max
            if (minCent > maxCent) {
                throw new IllegalArgumentException("最小值不能大于最大值");
            }
            // 4. 生成随机数
            Random random = new Random();
            return random.nextInt(maxCent - minCent + 1) + minCent;
        } catch (NumberFormatException e) {
            throw new IllegalArgumentException("范围值必须是有效的数字");
        }
    }
}

import java.util.Random;
public class HalfRangeRandom {
    public static void main(String[] args) {
        int number1 = 20;
        int random1 = getRandomAroundHalf(number1);
        System.out.println(number1 + " 的一半范围随机数: " + random1);
        int number2 = 35;
        int random2 = getRandomAroundHalf(number2);
        System.out.println(number2 + " 的一半范围随机数: " + random2);
    }
    public static int getRandomAroundHalf(int number) {
        // 1. 计算一半值（整数除法自动向下取整）
        int half = number / 2;
        // 2. 确定范围：half-5 到 half+5
        int min = half - 5;
        int max = half + 5;
        // 3. 确保最小值不小于0（可根据需求调整）
        min = Math.max(min, 0);
        // 4. 生成随机数
        Random random = new Random();
        return random.nextInt(max - min + 1) + min;
    }
}