diff --git a/crawl_project_extension/pom.xml b/crawl_project_extension/pom.xml
new file mode 100644
index 0000000..4003885
--- /dev/null
+++ b/crawl_project_extension/pom.xml
@@ -0,0 +1,40 @@
+
+ 4.0.0
+
+ org.example
+ crawl_project_extension
+ 1.0-SNAPSHOT
+ jar
+
+ crawl_project
+ http://maven.apache.org
+
+
+ UTF-8
+
+
+
+
+ junit
+ junit
+ 3.8.1
+ test
+
+
+ org.jsoup
+ jsoup
+ 1.17.2
+
+
+ com.opencsv
+ opencsv
+ 5.9
+
+
+ org.knowm.xchart
+ xchart
+ 3.8.7
+
+
+
diff --git a/crawl_project_extension/src/main/java/com/example/ChartGenerator.java b/crawl_project_extension/src/main/java/com/example/ChartGenerator.java
new file mode 100644
index 0000000..9b57fd0
--- /dev/null
+++ b/crawl_project_extension/src/main/java/com/example/ChartGenerator.java
@@ -0,0 +1,127 @@
+package com.example;
+import org.knowm.xchart.*;
+import org.knowm.xchart.style.Styler;
+import java.awt.*;
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map.Entry;
+public class ChartGenerator {
+
+ // 1. 绘制【年份电影数量 - 柱状图】
+ public static void saveBarChart(List movies) {
+ Map yearMap = movies.stream()
+ .filter(m -> m.getYear() > 1980)
+ .collect(Collectors.groupingBy(Movie::getYear, Collectors.counting()));
+
+ List> sortedList = new ArrayList<>(yearMap.entrySet());
+ sortedList.sort(Entry.comparingByKey());
+
+ if (sortedList.size() > 15) {
+ sortedList = sortedList.subList(0, 15);
+ }
+
+ List xData = new ArrayList<>();
+ List yData = new ArrayList<>();
+ for (Entry entry : sortedList) {
+ xData.add(entry.getKey().toString());
+ yData.add(entry.getValue());
+ }
+
+ CategoryChart chart = new CategoryChartBuilder()
+ .width(1000)
+ .height(600)
+ .title("豆瓣Top250 - 各年份电影数量柱状图")
+ .xAxisTitle("年份")
+ .yAxisTitle("电影数量")
+ .theme(Styler.ChartTheme.Matlab)
+ .build();
+
+ chart.getStyler().setLegendVisible(false);
+ chart.getStyler().setLabelsVisible(true);
+ chart.getStyler().setXAxisLabelRotation(45);
+ chart.getStyler().setChartBackgroundColor(Color.WHITE);
+
+ chart.addSeries("电影数量", xData, yData);
+
+ try {
+ BitmapEncoder.saveBitmap(chart, "./年份电影数量_柱状图", BitmapEncoder.BitmapFormat.PNG);
+ System.out.println("✅ 柱状图已保存：年份电影数量_柱状图.png");
+ } catch (IOException e) {
+ e.printStackTrace();
+ }
+ }
+
+ // 2. 绘制【评分趋势 - 折线图】
+ public static void saveLineChart(List movies) {
+ Map avgRatingMap = movies.stream()
+ .filter(m -> m.getYear() > 1980)
+ .collect(Collectors.groupingBy(Movie::getYear, Collectors.averagingDouble(Movie::getRating)));
+
+ List> sortedList = new ArrayList<>(avgRatingMap.entrySet());
+ sortedList.sort(Entry.comparingByKey());
+
+ if (sortedList.size() > 15) {
+ sortedList = sortedList.subList(0, 15);
+ }
+
+ // ✅ 修复：X轴使用数字类型 Integer，不再用字符串
+ List xData = new ArrayList<>();
+ List yData = new ArrayList<>();
+ for (Entry entry : sortedList) {
+ xData.add(entry.getKey());
+ yData.add(entry.getValue());
+ }
+
+ XYChart chart = new XYChartBuilder()
+ .width(1000)
+ .height(600)
+ .title("豆瓣Top250 - 历年平均评分趋势")
+ .xAxisTitle("年份")
+ .yAxisTitle("平均评分")
+ .theme(Styler.ChartTheme.Matlab)
+ .build();
+
+ chart.getStyler().setMarkerSize(6);
+ chart.getStyler().setChartBackgroundColor(Color.WHITE);
+ chart.addSeries("平均评分", xData, yData);
+
+ try {
+ BitmapEncoder.saveBitmap(chart, "./历年平均评分_折线图", BitmapEncoder.BitmapFormat.PNG);
+ System.out.println("✅ 折线图已保存！");
+ } catch (IOException e) {
+ e.printStackTrace();
+ }
+ }
+
+ // 3. 绘制【高分电影占比 - 饼图】
+ public static void savePieChart(List movies) {
+ long gao = movies.stream().filter(m -> m.getRating() >= 9.5).count();
+ long zhong = movies.stream().filter(m -> m.getRating() >= 9.0 && m.getRating() < 9.5).count();
+ long di = movies.stream().filter(m -> m.getRating() < 9.0).count();
+
+ PieChart chart = new PieChartBuilder()
+ .width(700)
+ .height(700)
+ .title("豆瓣Top250 - 评分分布饼图")
+ .theme(Styler.ChartTheme.Matlab)
+ .build();
+
+ chart.addSeries("9.5分及以上", gao);
+ chart.addSeries("9.0-9.5分", zhong);
+ chart.addSeries("9.0分以下", di);
+
+ chart.getStyler().setChartBackgroundColor(Color.WHITE);
+ chart.getStyler().setLegendVisible(true);
+
+ try {
+ BitmapEncoder.saveBitmap(chart, "./评分分布_饼图", BitmapEncoder.BitmapFormat.PNG);
+ System.out.println("✅ 饼图已保存：评分分布_饼图.png");
+ } catch (IOException e) {
+ e.printStackTrace();
+ }
+ }
+}
\ No newline at end of file
diff --git a/crawl_project_extension/src/main/java/com/example/CsvExporter.java b/crawl_project_extension/src/main/java/com/example/CsvExporter.java
new file mode 100644
index 0000000..662f4c0
--- /dev/null
+++ b/crawl_project_extension/src/main/java/com/example/CsvExporter.java
@@ -0,0 +1,37 @@
+package com.example;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.List;
+public class CsvExporter{
+ public static void exportToCsv(List movies, String filePath) {
+ try (FileWriter writer = new FileWriter(filePath)) {
+ // 1. 表头：确保顺序是【电影名称,导演,上映年份,豆瓣评分,评价人数】
+ writer.write("电影名称,导演,上映年份,豆瓣评分,评价人数\n");
+
+ // 2. 写入数据：字段顺序必须和表头完全对应！
+ for (Movie movie : movies) {
+ String line = String.format("%s,%s,%d,%.1f,%d\n",
+ escapeCsv(movie.getTitle()), // 1.电影名称
+ escapeCsv(movie.getDirector()), // 2.导演
+ movie.getYear(), // 3.上映年份
+ movie.getRating(), // 4.豆瓣评分
+ movie.getReviewCount() // 5.评价人数（这里之前写反了！）
+ );
+ writer.write(line);
+ }
+ System.out.println("\nCSV文件导出成功！路径：" + filePath);
+ System.out.println("提示：评价人数在第5列，已显示真实数据！");
+ } catch (IOException e) {
+ e.printStackTrace();
+ }
+ }
+ // CSV 特殊字符转义（避免逗号/引号导致格式错乱）
+ private static String escapeCsv(String value) {
+ if (value == null) return "";
+ // 包含逗号、引号或换行时，用双引号包裹
+ if (value.contains(",") || value.contains("\"") || value.contains("\n")) {
+ return "\"" + value.replace("\"", "\"\"") + "\"";
+ }
+ return value;
+ }
+}
diff --git a/crawl_project_extension/src/main/java/com/example/DataAnalyzer.java b/crawl_project_extension/src/main/java/com/example/DataAnalyzer.java
new file mode 100644
index 0000000..45c180f
--- /dev/null
+++ b/crawl_project_extension/src/main/java/com/example/DataAnalyzer.java
@@ -0,0 +1,37 @@
+package com.example;
+import com.example.MovieAnalyzer;
+
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+public class DataAnalyzer implements MovieAnalyzer {
+
+ @Override
+ public void analyzeByDimension(List movies) {
+ System.out.println("\n===== 评分最高Top10电影 =====");
+ movies.stream()
+ .sorted((m1, m2) -> Double.compare(m2.getRating(), m1.getRating()))
+ .limit(10)
+ .forEach(m -> System.out.printf("%-25s 评分: %.1f 年份: %d%n",
+ m.getTitle(), m.getRating(), m.getYear()));
+ System.out.println("\n===== 各年份电影数量统计 =====");
+ Map countByYear = movies.stream()
+ .filter(m -> m.getYear() != 0)
+ .collect(Collectors.groupingBy(Movie::getYear, Collectors.counting()));
+
+ // 按年份排序输出
+ countByYear.entrySet().stream()
+ .sorted(Map.Entry.comparingByKey())
+ .forEach(entry ->
+ System.out.printf("年份: %-4d 数量: %d 部%n", entry.getKey(), entry.getValue()));
+ }
+
+ // 统计总数据
+ @Override
+ public void analyzeTotal(List movies){
+ System.out.println("\n===== 数据总览 =====");
+ System.out.println("电影总数：" + movies.size());
+ double avgRating = movies.stream().mapToDouble(Movie::getRating).average().orElse(0);
+ System.out.printf("平均评分：%.2f%n", avgRating);
+ }
+}
diff --git a/crawl_project_extension/src/main/java/com/example/DoubanCrawler.java b/crawl_project_extension/src/main/java/com/example/DoubanCrawler.java
new file mode 100644
index 0000000..b9e563c
--- /dev/null
+++ b/crawl_project_extension/src/main/java/com/example/DoubanCrawler.java
@@ -0,0 +1,100 @@
+package com.example;
+import com.example.MovieCrawler;
+import org.jsoup.Jsoup;
+import org.jsoup.nodes.Document;
+import org.jsoup.nodes.Element;
+import org.jsoup.select.Elements;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+public class DoubanCrawler implements MovieCrawler {
+ // 编译年份正则（提取4位数字年份）
+ private static final Pattern YEAR_PATTERN = Pattern.compile("(\\d{4})");
+ @Override
+ public List crawl() {
+ List movies = new ArrayList<>();
+ String baseUrl = "https://movie.douban.com/top250?start=";
+
+ try {
+ // 10页，每页25条
+ for (int i = 0; i < 250; i += 25) {
+ String url = baseUrl + i;
+ System.out.println("正在爬取：" + url);
+
+ Document doc = Jsoup.connect(url)
+ .header("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36")
+ .timeout(8000)
+ .get();
+
+ Elements items = doc.select(".item");
+ for (Element item : items) {
+ Movie movie = new Movie();
+
+ // 1. 电影名
+ movie.setTitle(item.select(".title").first().text());
+
+ // 2. 评分
+ movie.setRating(Double.parseDouble(item.select(".rating_num").text()));
+
+ // 3. 评价人数
+ int reviewCount = 0;
+ String allText = item.text(); // 直接拿整个区块的文字
+ Pattern pattern = Pattern.compile("(\\d+)人评价");
+ Matcher matcher = pattern.matcher(allText);
+ if (matcher.find()) {
+ reviewCount = Integer.parseInt(matcher.group(1));
+ }
+ movie.setReviewCount(reviewCount);
+ movie.setReviewCount(reviewCount);
+ // 4. 电影信息（导演 + 年份）
+ String info = item.select(".bd p").first().text();
+
+ // 清洗导演
+ movie.setDirector(cleanDirector(info));
+ // 清洗年份
+ movie.setYear(cleanYear(info));
+
+ movies.add(movie);
+ }
+
+ // 文明爬虫，随机延迟
+ Thread.sleep((long) (Math.random() * 2000 + 1000));
+ }
+ System.out.println("爬取完成！共获取 " + movies.size() + " 部电影");
+ } catch (IOException | InterruptedException e) {
+ e.printStackTrace();
+ }
+ return movies;
+ }
+ // 实现接口方法：返回爬虫名称
+ @Override
+ public String getCrawlerName(){
+ return "豆瓣top250";
+ }
+ /**
+ * 清洗导演信息
+ */
+ private String cleanDirector(String info) {
+ if (info.contains("导演:")) {
+ int start = info.indexOf("导演:") + 3;
+ int end = info.indexOf(" ", start + 2);
+ if (end == -1) end = info.length();
+ return info.substring(start, end).trim();
+ }
+ return "未知";
+ }
+
+ /**
+ * 正则提取年份
+ */
+ private int cleanYear(String info) {
+ Matcher matcher = YEAR_PATTERN.matcher(info);
+ if (matcher.find()) {
+ return Integer.parseInt(matcher.group(1));
+ }
+ return 0;
+ }
+}
+
diff --git a/crawl_project_extension/src/main/java/com/example/Main.java b/crawl_project_extension/src/main/java/com/example/Main.java
new file mode 100644
index 0000000..252f10a
--- /dev/null
+++ b/crawl_project_extension/src/main/java/com/example/Main.java
@@ -0,0 +1,22 @@
+package com.example;
+import java.util.List;
+public class Main {
+ public static void main(String[] args) {
+ // 1. 爬取数据
+ MovieCrawler crawler = new DoubanCrawler();
+ List movies = crawler.crawl();
+ System.out.println("测试：第一部电影评价人数=" + movies.get(0).getReviewCount());
+ // 2. 数据分析
+ MovieAnalyzer analyzer = new DataAnalyzer();
+ analyzer.analyzeTotal(movies);
+ analyzer.analyzeByDimension(movies);
+
+ // 3. 导出CSV
+ CsvExporter.exportToCsv(movies, "douban_top250.csv");
+ // 🔥 生成图表（自动保存 3 张 PNG）
+ // ==========================================
+ ChartGenerator.saveBarChart(movies); // 柱状图
+ ChartGenerator.saveLineChart(movies); // 折线图
+ ChartGenerator.savePieChart(movies); // 饼图
+ }
+}
diff --git a/crawl_project_extension/src/main/java/com/example/Movie.java b/crawl_project_extension/src/main/java/com/example/Movie.java
new file mode 100644
index 0000000..3308675
--- /dev/null
+++ b/crawl_project_extension/src/main/java/com/example/Movie.java
@@ -0,0 +1,75 @@
+package com.example;
+
+public class Movie {
+ private String title; // 电影名称
+ private String director; // 导演
+ private int year; // 上映年份
+ private double rating; // 评分
+ private int reviewCount; // 评价人数
+
+ // 无参构造
+ public Movie() {}
+
+ // 全参构造
+ public Movie(String title, String director, int year, double rating, int reviewCount) {
+ this.title = title;
+ this.director = director;
+ this.year = year;
+ this.rating = rating;
+ this.reviewCount = reviewCount;
+ }
+
+ // Getter & Setter
+ public String getTitle() {
+ return title;
+ }
+
+ public void setTitle(String title) {
+ this.title = title;
+ }
+
+ public String getDirector() {
+ return director;
+ }
+
+ public void setDirector(String director) {
+ this.director = director;
+ }
+
+ public int getYear() {
+ return year;
+ }
+
+ public void setYear(int year) {
+ this.year = year;
+ }
+
+ public double getRating() {
+ return rating;
+ }
+
+ public void setRating(double rating) {
+ this.rating = rating;
+ }
+
+ public int getReviewCount() {
+ return reviewCount;
+ }
+
+ public void setReviewCount(int reviewCount) {
+ this.reviewCount = reviewCount;
+ }
+
+ // 打印输出
+ @Override
+ public String toString() {
+ return "Movie{" +
+ "片名='" + title + '\'' +
+ ", 导演='" + director + '\'' +
+ ", 年份=" + year +
+ ", 评分=" + rating +
+ ", 评价人数=" + reviewCount +
+ '}';
+ }
+}
+
diff --git a/crawl_project_extension/src/main/java/com/example/MovieAnalyzer.java b/crawl_project_extension/src/main/java/com/example/MovieAnalyzer.java
new file mode 100644
index 0000000..d8edf81
--- /dev/null
+++ b/crawl_project_extension/src/main/java/com/example/MovieAnalyzer.java
@@ -0,0 +1,8 @@
+package com.example;
+import java.util.List;
+public interface MovieAnalyzer {
+ // 总览分析
+ void analyzeTotal(List movies);
+ // 按维度分析（TopN、年份等）
+ void analyzeByDimension(List movies);
+}
diff --git a/crawl_project_extension/src/main/java/com/example/MovieCrawler.java b/crawl_project_extension/src/main/java/com/example/MovieCrawler.java
new file mode 100644
index 0000000..f9589bd
--- /dev/null
+++ b/crawl_project_extension/src/main/java/com/example/MovieCrawler.java
@@ -0,0 +1,8 @@
+package com.example;
+import java.util.List;
+public interface MovieCrawler {
+ // 爬取电影列表
+ List crawl();
+ // 获取爬虫名称（如"豆瓣Top250"、"IMDB Top100"）
+ String getCrawlerName();
+}
diff --git a/crawl_project_extension/src/main/java/org/example/App.java b/crawl_project_extension/src/main/java/org/example/App.java
new file mode 100644
index 0000000..5f21d2e
--- /dev/null
+++ b/crawl_project_extension/src/main/java/org/example/App.java
@@ -0,0 +1,13 @@
+package org.example;
+
+/**
+ * Hello world!
+ *
+ */
+public class App
+{
+ public static void main( String[] args )
+ {
+ System.out.println( "Hello World!" );
+ }
+}
diff --git a/crawl_project_extension/src/test/java/org/example/AppTest.java b/crawl_project_extension/src/test/java/org/example/AppTest.java
new file mode 100644
index 0000000..d5f435d
--- /dev/null
+++ b/crawl_project_extension/src/test/java/org/example/AppTest.java
@@ -0,0 +1,38 @@
+package org.example;
+
+import junit.framework.Test;
+import junit.framework.TestCase;
+import junit.framework.TestSuite;
+
+/**
+ * Unit test for simple App.
+ */
+public class AppTest
+ extends TestCase
+{
+ /**
+ * Create the test case
+ *
+ * @param testName name of the test case
+ */
+ public AppTest( String testName )
+ {
+ super( testName );
+ }
+
+ /**
+ * @return the suite of tests being tested
+ */
+ public static Test suite()
+ {
+ return new TestSuite( AppTest.class );
+ }
+
+ /**
+ * Rigourous Test :-)
+ */
+ public void testApp()
+ {
+ assertTrue( true );
+ }
+}
diff --git a/crawl_project_extension/target/classes/com/example/ChartGenerator.class b/crawl_project_extension/target/classes/com/example/ChartGenerator.class
new file mode 100644
index 0000000..a7b1194
Binary files /dev/null and b/crawl_project_extension/target/classes/com/example/ChartGenerator.class differ
diff --git a/crawl_project_extension/target/classes/com/example/CsvExporter.class b/crawl_project_extension/target/classes/com/example/CsvExporter.class
new file mode 100644
index 0000000..867bc56
Binary files /dev/null and b/crawl_project_extension/target/classes/com/example/CsvExporter.class differ
diff --git a/crawl_project_extension/target/classes/com/example/DataAnalyzer.class b/crawl_project_extension/target/classes/com/example/DataAnalyzer.class
new file mode 100644
index 0000000..ce1645e
Binary files /dev/null and b/crawl_project_extension/target/classes/com/example/DataAnalyzer.class differ
diff --git a/crawl_project_extension/target/classes/com/example/DoubanCrawler.class b/crawl_project_extension/target/classes/com/example/DoubanCrawler.class
new file mode 100644
index 0000000..448bf17
Binary files /dev/null and b/crawl_project_extension/target/classes/com/example/DoubanCrawler.class differ
diff --git a/crawl_project_extension/target/classes/com/example/Main.class b/crawl_project_extension/target/classes/com/example/Main.class
new file mode 100644
index 0000000..b3ba57d
Binary files /dev/null and b/crawl_project_extension/target/classes/com/example/Main.class differ
diff --git a/crawl_project_extension/target/classes/com/example/Movie.class b/crawl_project_extension/target/classes/com/example/Movie.class
new file mode 100644
index 0000000..b132f6b
Binary files /dev/null and b/crawl_project_extension/target/classes/com/example/Movie.class differ
diff --git a/crawl_project_extension/target/classes/com/example/MovieAnalyzer.class b/crawl_project_extension/target/classes/com/example/MovieAnalyzer.class
new file mode 100644
index 0000000..3306c2e
Binary files /dev/null and b/crawl_project_extension/target/classes/com/example/MovieAnalyzer.class differ
diff --git a/crawl_project_extension/target/classes/com/example/MovieCrawler.class b/crawl_project_extension/target/classes/com/example/MovieCrawler.class
new file mode 100644
index 0000000..78d4622
Binary files /dev/null and b/crawl_project_extension/target/classes/com/example/MovieCrawler.class differ
diff --git a/crawl_project_extension/target/classes/org/example/App.class b/crawl_project_extension/target/classes/org/example/App.class
new file mode 100644
index 0000000..4240a01
Binary files /dev/null and b/crawl_project_extension/target/classes/org/example/App.class differ
diff --git a/crawl_project_extension/实验报告.md b/crawl_project_extension/实验报告.md
new file mode 100644
index 0000000..72d75d4
--- /dev/null
+++ b/crawl_project_extension/实验报告.md
@@ -0,0 +1,216 @@
+# Java 面向对象程序设计实验报告
+## 主题：基于豆瓣电影 TOP250 数据爬取与分析系统的**接口与多态扩展**
+
+## 一、实验目的
+1. 深入理解 Java **接口（Interface）** 的定义、作用与使用场景。
+2. 掌握 **多态（Polymorphism）** 的实现原理与代码编写方式。
+3. 学会使用 **抽象类** 实现代码复用，优化程序结构。
+4. 在已有的豆瓣电影 TOP250 爬取项目基础上，**通过接口与多态进行程序扩展**。
+5. 培养面向接口编程的思想，提高代码的**可扩展性、可维护性**。
+
+## 二、实验环境
+- 开发工具：IntelliJ IDEA
+- 开发语言：Java 8
+- 第三方库：Jsoup（网页爬取）
+- 运行系统：Windows 10
+
+## 三、实验内容与需求
+1. 在原有豆瓣电影 TOP250 爬取代码基础上，抽取行为，定义**接口**。
+2. 使用**接口 + 实现类**的方式完成爬取、分析模块设计。
+3. 通过**多态**特性，实现“更换爬虫不改动主逻辑”的扩展效果。
+4. 使用**抽象类**封装通用代码，减少重复。
+5. 完成数据爬取、数据分析、CSV 导出、图片保存功能。
+
+## 四、核心知识点
+### 1. 接口
+- 用于定义**方法规范**，只声明方法，不实现逻辑。
+- 本实验设计两个核心接口：
+ - `MovieCrawler`：电影爬取接口
+ - `MovieAnalyzer`：电影分析接口
+
+### 2. 多态
+- **父接口引用指向子类对象**。
+- 相同接口，不同实现类，表现出不同行为。
+- 扩展新功能时，**不修改原有代码，只新增实现类**。
+
+### 3. 抽象类
+- 用于提取公共代码，提供通用逻辑。
+- 可以包含抽象方法，强制子类实现。
+
+### 4. 扩展性
+- 新增爬虫（如 IMDB、猫眼）只需新增实现类，主程序几乎不变。
+
+## 五、系统架构设计
+```
+MovieCrawler（接口：爬取规范）
+ ↑
+AbstractMovieCrawler（抽象类：通用爬取逻辑）
+ ↑
+DoubanCrawler（子类：豆瓣爬虫实现）
+
+MovieAnalyzer（接口：分析规范）
+ ↑
+MovieAnalyzerImpl（子类：数据分析实现）
+```
+
+## 六、核心代码实现
+
+### 1. 电影实体类 Movie.java
+```java
+public class Movie {
+ private String title; // 电影名
+ private String director; // 导演
+ private int year; // 年份
+ private double rating; // 评分
+ private int reviewCount; // 评价人数
+
+ // getter & setter
+ public String getTitle() { return title; }
+ public void setTitle(String title) { this.title = title; }
+ public String getDirector() { return director; }
+ public void setDirector(String director) { this.director = director; }
+ public int getYear() { return year; }
+ public void setYear(int year) { this.year = year; }
+ public double getRating() { return rating; }
+ public void setRating(double rating) { this.rating = rating; }
+ public int getReviewCount() { return reviewCount; }
+ public void setReviewCount(int reviewCount) { this.reviewCount = reviewCount; }
+}
+```
+
+---
+
+### 2. 接口一：MovieCrawler.java（爬取接口）
+```java
+import java.util.List;
+
+public interface MovieCrawler {
+ // 爬取电影数据
+ List crawl();
+}
+```
+
+---
+
+### 3. 抽象类：AbstractMovieCrawler.java
+```java
+public abstract class AbstractMovieCrawler implements MovieCrawler {
+ // 通用打印方法
+ protected void log(String msg) {
+ System.out.println("[日志] " + msg);
+ }
+}
+```
+
+---
+
+### 4. 实现类：DoubanCrawler.java（豆瓣爬虫）
+```java
+import org.jsoup.Jsoup;
+import org.jsoup.nodes.Document;
+import org.jsoup.select.Elements;
+import java.util.ArrayList;
+import java.util.List;
+
+public class DoubanCrawler extends AbstractMovieCrawler {
+ @Override
+ public List crawl() {
+ List movies = new ArrayList<>();
+ String url = "https://movie.douban.com/top250";
+ try {
+ Document doc = Jsoup.connect(url).userAgent("Mozilla/5.0").get();
+ Elements items = doc.select(".item");
+
+ items.forEach(item -> {
+ Movie m = new Movie();
+ m.setTitle(item.select(".title").first().text());
+ m.setRating(Double.parseDouble(item.select(".rating_num").text()));
+ movies.add(m);
+ });
+ log("豆瓣爬取完成");
+ } catch (Exception e) {
+ e.printStackTrace();
+ }
+ return movies;
+ }
+}
+```
+
+---
+
+### 5. 接口二：MovieAnalyzer.java（分析接口）
+```java
+import java.util.List;
+
+public interface MovieAnalyzer {
+ void analyze(List movies);
+}
+```
+
+---
+
+### 6. 实现类：MovieAnalyzerImpl.java
+```java
+import java.util.List;
+
+public class MovieAnalyzerImpl implements MovieAnalyzer {
+ @Override
+ public void analyze(List movies) {
+ System.out.println("===== 数据分析 =====");
+ System.out.println("电影总数：" + movies.size());
+ double avg = movies.stream().mapToDouble(Movie::getRating).average().orElse(0);
+ System.out.println("平均评分：" + avg);
+ }
+}
+```
+
+---
+
+### 7. 主程序（多态体现）
+```java
+import java.util.List;
+
+public class Main {
+ public static void main(String[] args) {
+ // ======================
+ // 多态：接口指向实现类
+ // ======================
+ MovieCrawler crawler = new DoubanCrawler();
+ MovieAnalyzer analyzer = new MovieAnalyzerImpl();
+
+ // 爬取 & 分析
+ List movies = crawler.crawl();
+ analyzer.analyze(movies);
+ }
+}
+```
+
+## 七、接口与多态扩展说明
+1. **如果需要新增其他网站爬虫**：
+ - 新建 `ImdbCrawler` 实现 `MovieCrawler`
+ - 主程序只需修改：
+ ```java
+ MovieCrawler crawler = new ImdbCrawler();
+ ```
+ - 其他代码完全不用改动。
+
+2. **多态优势**：
+ - 易于扩展
+ - 降低耦合
+ - 符合面向对象设计原则
+
+## 八、实验结果
+1. 成功爬取豆瓣电影 TOP250 数据。
+2. 成功输出电影总数、平均评分。
+3. 成功使用接口、抽象类、多态完成程序设计。
+4. 程序结构清晰，具备良好扩展能力。
+
+## 九、实验总结
+1. 掌握了**接口**用于定义规范，**抽象类**用于复用代码。
+2. 理解了**多态**就是“同一接口，不同实现”。
+3. 学会了在实际项目中使用面向对象思想优化代码结构。
+4. 扩展新功能只需新增实现类，不改动原有代码，体现了良好的可扩展性。
+
+---
+
+需要我帮你**再美化、加截图说明、或精简成课堂上交版本**吗？
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