实验五

实验五/AnimatedMovie.java

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+public class AnimatedMovie extends Movie {
+    private String studio;
+
+    public AnimatedMovie(String title, int year, double rating, String genre, String studio) {
+        super(title, year, rating, genre);
+        this.studio = studio;
+    }
+
+    @Override
+    public void play() {
+        System.out.println("动画电影播放：" + getTitle() + "，制作公司：" + studio);
+    }
+}

实验五/CrawlStrategy.java

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+import org.jsoup.nodes.Element;
+import java.util.List;
+
+// 策略接口：所有网站爬取都必须实现这两个方法
+public interface CrawlStrategy {
+    // 爬取电影
+    List<Movie> crawl(int limit);
+    // 解析电影元素
+    Movie parseMovie(Element element);
+}

实验五/CrawlerContext.java

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+import java.util.ArrayList;
+import java.util.List;
+
+// 上下文：负责管理和执行策略
+public class CrawlerContext {
+    // 组合多个策略（可同时爬多个网站）
+    private List<CrawlStrategy> strategies = new ArrayList<>();
+
+    // 添加一个爬取策略
+    public void addStrategy(CrawlStrategy strategy) {
+        strategies.add(strategy);
+    }
+
+    // 执行所有策略
+    public List<Movie> executeAllCrawl(int limit) {
+        List<Movie> result = new ArrayList<>();
+        for (CrawlStrategy strategy : strategies) {
+            result.addAll(strategy.crawl(limit));
+        }
+        return result;
+    }
+
+    // 清空策略
+    public void clearStrategies() {
+        strategies.clear();
+    }
+}

实验五/DoubanStrategy.java

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+import org.jsoup.Jsoup;
+import org.jsoup.nodes.Document;
+import org.jsoup.nodes.Element;
+import org.jsoup.select.Elements;
+import java.util.ArrayList;
+import java.util.List;
+
+public class DoubanStrategy implements CrawlStrategy {
+    private static final String URL = "https://movie.douban.com/top250?start=0";
+
+    @Override
+    public List<Movie> crawl(int limit) {
+        List<Movie> list = new ArrayList<>();
+        try {
+            Document doc = Jsoup.connect(URL)
+                    .userAgent("Mozilla/5.0")
+                    .timeout(10000)
+                    .get();
+
+            Elements items = doc.select(".item");
+            int count = 0;
+            for (Element e : items) {
+                if (count >= limit) break;
+                Movie m = parseMovie(e);
+                if (m != null) {
+                    list.add(m);
+                    count++;
+                }
+            }
+        } catch (Exception ex) {
+            System.out.println("豆瓣抓取失败（反爬保护），已跳过");
+        }
+        return list;
+    }
+
+    @Override
+    public Movie parseMovie(Element element) {
+        try {
+            String title = element.select(".hd .title").first().text();
+            double rating = Double.parseDouble(element.select(".rating_num").first().text());
+            return new TheatreMovie(title, 2024, rating, "电影", 49.9);
+        } catch (Exception e) {
+            return null;
+        }
+    }
+}

实验五/DouyinMovie.java

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+public class DouyinMovie extends Movie {
+    private String hotValue;
+
+    public DouyinMovie(String title, int year, double rating, String genre, String hotValue) {
+        super(title, year, rating, genre);
+        this.hotValue = hotValue;
+    }
+
+    @Override
+    public void play() {
+        System.out.println("抖音视频：" + getTitle() + "，热度：" + hotValue);
+    }
+}

实验五/DouyinStrategy.java

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+import org.jsoup.Jsoup;
+import org.jsoup.nodes.Document;
+import org.jsoup.nodes.Element;
+import org.jsoup.select.Elements;
+import java.util.ArrayList;
+import java.util.List;
+
+public class DouyinStrategy implements CrawlStrategy {
+    private static final String URL = "https://www.douyin.com";
+
+    @Override
+    public List<Movie> crawl(int limit) {
+        List<Movie> list = new ArrayList<>();
+        try {
+            Document doc = Jsoup.connect(URL)
+                    .userAgent("Mozilla/5.0")
+                    .timeout(10000)
+                    .get();
+
+            Elements items = doc.select("div");
+            int count = 0;
+            for (Element e : items) {
+                if (count >= limit) break;
+                Movie m = parseMovie(e);
+                if (m != null) {
+                    list.add(m);
+                    count++;
+                }
+            }
+        } catch (Exception ex) {
+            System.out.println("抖音抓取失败（反爬保护），已跳过");
+        }
+        return list;
+    }
+
+    @Override
+    public Movie parseMovie(Element element) {
+        try {
+            String title = element.select("h3").first().text();
+            return new DouyinMovie(title, 2024, 9.5, "视频", "100w+");
+        } catch (Exception e) {
+            return null;
+        }
+    }
+}

实验五/Main.java

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+import java.util.List;
+
+public class Main {
+    public static void main(String[] args) {
+        // 1. 创建上下文
+        CrawlerContext context = new CrawlerContext();
+
+        // 2. 动态添加策略（想爬哪个就加哪个，随时增删）
+        context.addStrategy(new DoubanStrategy());
+        context.addStrategy(new XiaohongshuStrategy());
+        context.addStrategy(new DouyinStrategy());
+
+        // 3. 执行爬取
+        List<Movie> movies = context.executeAllCrawl(2);
+
+        // 4. 多态播放
+        for (Movie m : movies) {
+            m.play();
+        }
+    }
+}

实验五/Movie.java

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+public abstract class Movie implements MoviePlayable {
+    private String title;
+    private int year;
+    private double rating;
+    private String genre;
+
+    public Movie(String title, int year, double rating, String genre) {
+        this.title = title;
+        this.year = year;
+        this.rating = rating;
+        this.genre = genre;
+    }
+
+    // 接口方法，留给子类实现
+    @Override
+    public abstract void play();
+
+    // getter
+    public String getTitle() { return title; }
+    public int getYear() { return year; }
+    public double getRating() { return rating; }
+    public String getGenre() { return genre; }
+}

实验五/MoviePlayable.java

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+public interface MoviePlayable {
+    void play();
+}

实验五/TheatreMovie.java

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+public class TheatreMovie extends Movie {
+    private double price;
+
+    public TheatreMovie(String title, int year, double rating, String genre, double price) {
+        super(title, year, rating, genre);
+        this.price = price;
+    }
+
+    @Override
+    public void play() {
+        System.out.println("院线电影播放：" + getTitle() + "，票价：" + price);
+    }
+}

实验五/XiaohongshuMovie.java

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+public class XiaohongshuMovie extends Movie {
+    private String author;
+
+    public XiaohongshuMovie(String title, int year, double rating, String genre, String author) {
+        super(title, year, rating, genre);
+        this.author = author;
+    }
+
+    @Override
+    public void play() {
+        System.out.println("小红书笔记：" + getTitle() + "，作者：" + author);
+    }
+}

实验五/XiaohongshuStrategy.java

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+import org.jsoup.Jsoup;
+import org.jsoup.nodes.Document;
+import org.jsoup.nodes.Element;
+import org.jsoup.select.Elements;
+import java.util.ArrayList;
+import java.util.List;
+
+public class XiaohongshuStrategy implements CrawlStrategy {
+    private static final String URL = "https://www.xiaohongshu.com";
+
+    @Override
+    public List<Movie> crawl(int limit) {
+        List<Movie> list = new ArrayList<>();
+        try {
+            Document doc = Jsoup.connect(URL)
+                    .userAgent("Mozilla/5.0")
+                    .timeout(10000)
+                    .get();
+
+            Elements items = doc.select("div");
+            int count = 0;
+            for (Element e : items) {
+                if (count >= limit) break;
+                Movie m = parseMovie(e);
+                if (m != null) {
+                    list.add(m);
+                    count++;
+                }
+            }
+        } catch (Exception ex) {
+            System.out.println("小红书抓取失败（反爬保护），已跳过");
+        }
+        return list;
+    }
+
+    @Override
+    public Movie parseMovie(Element element) {
+        try {
+            String title = element.select("h2").first().text();
+            return new XiaohongshuMovie(title, 2024, 9.2, "笔记", "小红书用户");
+        } catch (Exception e) {
+            return null;
+        }
+    }
+}