java/w11/RetryUtils.java

public class RetryUtils {
    private static final long BASE_WAIT_MS = 500;
    private static final int MAX_RETRY = 5;

    @FunctionalInterface
    public interface RetryTask<T> {
        T execute() throws Exception;
    }

    public static <T> T retry(RetryTask<T> task) throws Exception {
        int attempt = 0;
        while (attempt < MAX_RETRY) {
            try {
                return task.execute();
            } catch (Exception e) {
                attempt++;
                if (attempt >= MAX_RETRY) {
                    System.out.println("最终失败: " + e.getMessage());
                    throw e;
                }
                long waitTime = BASE_WAIT_MS * (1L << attempt);
                System.out.println("尝试执行 #" + attempt + "... 失败");
                System.out.println("等待: " + waitTime + "ms");
                try {
                    Thread.sleep(waitTime);
                } catch (InterruptedException ie) {
                    Thread.currentThread().interrupt();
                    throw new RuntimeException(ie);
                }
            }
        }
        throw new IllegalStateException("重试逻辑异常");
    }

    public static void main(String[] args) throws Exception {
        RetryUtils.retry(() -> {
            System.out.println("尝试执行");
            throw new RuntimeException("模拟失败");
        });
    }
}