Java 使用正则表达式和IO实现爬虫以及503解决

基本套路：

第一步：获取小说每一章的url地址

第二步：获取章节url内容并使用正则表达式提取需要的内容

第三步：多线程封装，实现如下效果

最后测试。

代码：

内容获取封装：

public class WebSpider {
	//<a href="/35/35971/13555631.html"> 第1章:边哨* </a> -->{"/35/35971/13555631.html","第1章:边哨*"}
	// 存放所有章节列表和标题 
	private List<String[]> urlList;
	// 指定下载的跟目录
	private String rootDir;
	// 指定编码
	private String encoding;
	public WebSpider() {
		urlList = new ArrayList<String[]>();
	}
	public WebSpider(String titleUrl, Map<String, String> regexMap, String rootDir, String encoding) {
		this();
		this.rootDir = rootDir;
		this.encoding = encoding;
		initUrlList(titleUrl, regexMap);
	}

	/**
	 * 初始化小说所有章节列表 在构造方法中调用
	 * @param url
	 * @param regexMap
	 */
	private void initUrlList(String url, Map<String, String> regexMap) {
		StringBuffer sb = getContent(url, this.encoding);
		int urlIndex = Integer.parseInt(regexMap.get("urlIndex"));
		int titleIndex = Integer.parseInt(regexMap.get("titleIndex"));
		Pattern p = Pattern.compile(regexMap.get("regex"));
		Matcher m = p.matcher(sb);
		while (m.find()) {
			String[] strs = { m.group(urlIndex), m.group(titleIndex) };
			this.urlList.add(strs);
		}
	}

	/**
	 * 获取文本内容
	 * 
	 * @param urlPath
	 * @param enc
	 * @return
	 */
	public StringBuffer getContent(String urlPath, String enc) {
		StringBuffer strBuf;
		class Result{
			StringBuffer sb;
			public Result() {
				BufferedReader reader = null;
				HttpURLConnection conn = null;
				try {
					URL url = new URL(urlPath);
					conn = (HttpURLConnection) url.openConnection();
					conn.setRequestProperty("user-agent",
							"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36");
					reader = new BufferedReader(new InputStreamReader(conn.getInputStream(), enc));
					sb = new StringBuffer();
					String line;
					while ((line = reader.readLine()) != null) {
						sb.append(line).append("
");
					}
				} catch (Exception e) {
//					e.printStackTrace();
				} finally {
					try {
						if (reader != null) {
							reader.close();
						}
						conn.disconnect();
					} catch (IOException e) {
						e.printStackTrace();
					}
				}
			}
		}
		for(int i = 1; ; i++) {
			strBuf = new Result().sb;
			if(strBuf == null) {
				try {
					Thread.sleep(5000 * i);
					System.out.println("=====================等待 --》" + (5000 * i));
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
				continue;
			}
			break;
		}
		return strBuf;
	}

	/**
	 * 获取正则表达式匹配后内容
	 * @param url
	 * @param enc
	 * @param regex
	 * @param indexGroup
	 * @return
	 */
	public String getDestTxt(String url, String enc, String regex, int indexGroup) {
		StringBuffer sb = getContent(url, enc);
		StringBuffer result = new StringBuffer();
		Pattern p = Pattern.compile(regex);
		Matcher m = p.matcher(sb);
		while (m.find()) {
			result.append(m.group(indexGroup).replace("<br />", "
"));
		}
		return result.toString();
	}


	public String getRootDir() {
		return rootDir;
	}

	public List<String[]> getUrlList() {
		return urlList;
	}
}

多线程封装：

class Down implements Runnable {// 线程类
	private WebSpider spider;
	private String enc;// 编码 这个网站的标题列表编码和正文编码不一样
	private String bookName;// 书名
	// 分卷下载，指定开始和结束
	private int start;
	private int end;
	private Map<String, String> regexMap;

	public Down(WebSpider spider, Map<String, String> regexMap, String enc, String bookName, int start, int end) {
		this.spider = spider;
		this.regexMap = regexMap;
		this.enc = enc;
		this.bookName = bookName;
		this.start = start;
		this.end = end;
	}

	@Override
	public void run() {
		System.out.println(Thread.currentThread().getName() + "开始启动下载>>>>>");
		List<String[]> list = this.spider.getUrlList();
		String[] arr = null;
		for (int i = start; i < end; i++) {
			arr = list.get(i);
			String url = "https://www.luocs.cn" + arr[0];
			String title = arr[1];
			this.writeTOFile(url, this.regexMap.get("regex"), Integer.parseInt(this.regexMap.get("groupIndex")), title);
			if (i % 10 % 3 == 0) {
				System.out.println(Thread.currentThread().getName() + "下载进度-->" + (i % 10) + "0%");
			}
			// 暂停1~3秒爬取下一章节
			try {
				Thread.sleep((long) (1000L + Math.random() * 20000));
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
		System.out.println(Thread.currentThread().getName() + "下载完成！");

	}

	/**
	 * 写入到文件
	 * @param url 正文url 地址
	 * @param regex 正文匹配的正则表达式
	 * @param indexGroup 正文匹配的正则表达式分组
	 * @param title 每个章节的标题
	 */
	private void writeTOFile(String url, String regex, int indexGroup, String title) {
		String src = this.spider.getDestTxt(url, this.enc, regex, indexGroup);
		BufferedWriter writer = null;
		try {
			writer = new BufferedWriter(new FileWriter(
					new File(this.spider.getRootDir() + this.bookName + this.start + "--" + this.end + ".txt"), true));
			// 简单美化一下格式
			writer.append("*****").append(title).append("*****");
			writer.newLine();
			writer.append(src, 0, src.length());
			writer.newLine();
			writer.append("====================");
			writer.newLine();
			writer.flush();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if (writer != null) {
					writer.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
}

测试：

我这边直接写main方法测试：

public static void main(String[] args) {
		String url = "https://www.luocs.cn/35/35971/0.html";
		Map<String, String> map = new HashMap<String, String>();
		map.put("regex", "href='(.+html)'>(.+:{1}.+)</a>");
		map.put("urlIndex", "1");
		map.put("titleIndex", "2");
		WebSpider spider = new WebSpider(url, map, "f:/Game/", "gbk");
		Map<String, String> regexMap = new HashMap<String, String>();
		regexMap.put("regex", "(&nbsp;){4}(.+)");
		regexMap.put("groupIndex", "2");
		for (int i = 0; i < 2; i++) {
			Down d = new Down(spider, regexMap, "gb2312", "最强兵王", i * 10, (i + 1) * 10);
			new Thread(d, "线程 " + (i + 1) + "[" + (i * 10 + 1) + "~~" + ((i + 1) * 10 - 1) + "]:").start();
		}
	}

效果：

503失败后，等待一段时间再试

最后写到本地效果

如果把文本导入到手机，用UC或者QQ 浏览器插件打开，会自动区分章节，在配上背景色，那样阅读起来就真的是清爽无弹窗了。

这个网站不怎么好爬，大家可以找个好爬点的网站爬取。当然这个503处理也不是很好，各位路边的大神如果有更好的办法，请指教。