java/w10/StrategyFactory.java

package com.example.datacollect.strategy;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;

public class StrategyFactory {
    private final List<CrawlStrategy> strategies = new ArrayList<>();
    private final CrawlStrategy defaultStrategy;

    public StrategyFactory() {
        strategies.add(new HnuNewsStrategy());
        strategies.add(new BlogStrategy());
        strategies.add(new NewsStrategy());
        strategies.add(new RegexStrategy(".*\\.edu\\.cn$", 80));
        strategies.add(new RegexStrategy(".*\\.com$", 60));
        strategies.sort(Comparator.comparingInt(CrawlStrategy::getPriority).reversed());
        this.defaultStrategy = new DefaultStrategy();
    }

    public CrawlStrategy getStrategy(String url) {
        List<CrawlStrategy> matched = new ArrayList<>();
        for (CrawlStrategy s : strategies) {
            if (s.supports(url)) {
                matched.add(s);
            }
        }
        if (matched.isEmpty()) {
            return defaultStrategy;
        }
        if (matched.size() > 1) {
            System.out.println("WARNING: Multiple strategies matched for URL: " + url
                    + ", using highest priority: " + matched.get(0).getClass().getSimpleName());
        }
        return matched.get(0);
    }

    public void register(CrawlStrategy strategy) {
        strategies.add(strategy);
        strategies.sort(Comparator.comparingInt(CrawlStrategy::getPriority).reversed());
    }

    public List<CrawlStrategy> getAllStrategies() {
        return new ArrayList<>(strategies);
    }

    public CrawlStrategy getDefaultStrategy() {
        return defaultStrategy;
    }
}