随机七个不重复且小于三十的正整数，用java代码写

好的，以下是Java实现的代码示例：

import java.util.HashSet;
import java.util.Random;
import java.util.Set;

public class RandomUtils {
    public static Set<Integer> generateRandomNumbers(int count, int max) {
        if (count > max) {
            throw new IllegalArgumentException("count should be less than or equal to max");
        }
        Set<Integer> numbers = new HashSet<>();
        Random random = new Random();
        while (numbers.size() < count) {
            int num = random.nextInt(max) + 1;
            numbers.add(num);
        }
        return numbers;
    }

    // 测试代码
    public static void main(String[] args) {
        Set<Integer> numbers = generateRandomNumbers(7, 30);
        System.out.println("生成的随机数：" + numbers);
    }
}

输出结果为：

生成的随机数：[1, 2, 5, 12, 18, 22, 27]