JSoup在代码随机位置超时的原因排查求助

Hey Jacob, let's break down what's happening here and how to get your baseball project back on track. The issue you're facing is almost certainly anti-scraping protections kicking in from retrosheets.org, and here's the full breakdown:

What's Causing the Block? #

• Aggressive Request Frequency: Firing hundreds of requests in just 5 seconds is a huge red flag for websites. Retrosheets (like most public data hosts) has server limits and bot-detection systems—this kind of rapid-fire activity gets your IP address temporarily blocked, which explains why both your program freezes and your browser can't access the site afterward.
• No Request Throttling: Your loop runs requests back-to-back without any delay. Human users don't load 200 pages in 5 seconds, so the site's systems immediately flag you as a bot.
• (Less likely, but possible) Unmanaged Connections: If you're not reusing connections properly, you might exhaust the site's available server slots—but the browser block points strongly to an IP ban instead.

Fixes to Get Your Scraper Working #

Let's adjust your approach to play nice with the site:

1. Add Request Throttling #

The simplest fix is to add a delay between each request. Aim for at least 1-2 seconds per request (or longer if the site is strict). Here's how to modify your loop:

// Inside your loop after each request
try {
    doc = Jsoup.connect("https://www.retrosheet.org/boxesetc/index.html")
        .maxBodySize(0)
        .userAgent("Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/12.0.3 Safari/605.1.15")
        .get();
    
    // Process your document here...
    
    // Wait 1.5 seconds before the next request
    Thread.sleep(1500);
} catch (IOException | InterruptedException e) {
    e.printStackTrace();
    // Add a longer delay on failure before retrying
}

2. Use a Connection Pool #

Jsoup can reuse connections to reduce server load and make your scraper more efficient. Configure a pool to limit concurrent connections:

// Initialize once at the start of your program
ConnectionPool pool = new ConnectionPool(10, 10000); // 10 max connections, 10-second timeout

// Then in your loop:
doc = Jsoup.connect("your-target-url")
    .maxBodySize(0)
    .userAgent("your-UA-string")
    .connectionPool(pool)
    .get();

3. Respect robots.txt #

Check retrosheets.org's robots.txt (visit the root path to find it) to make sure you're only scraping paths they explicitly allow. Ignoring this can lead to permanent bans.

4. Rotate User Agents (Optional) #

While your current UA is a valid browser string, rotating between a few real browser UAs can make your requests look more human. Keep a list of up-to-date browser strings and pick one randomly for each request.

5. Handle Retries Gracefully #

If you get blocked temporarily, don't hammer the site with retries. Add exponential backoff: increase the delay each time a request fails (e.g., 2s, 4s, 8s) before trying again.

Final Note #

Retrosheets provides amazing baseball data, but they're a small operation—be respectful of their server resources. If you need large volumes of data, check if they offer bulk downloads (many sports data sites do!) instead of scraping individual pages. That's better for both you and the site.

内容的提问来源于stack exchange，提问作者Jacob Snyder