爬虫(整页)

作者: 晨曦_hero | 来源:发表于2017-09-22 10:27 被阅读2次

    public class Text02 {
    public static void main(String[] args) {
    // 图片下载对象
    final ImageDownload imgDownload = new ImageDownload();
    // 生产图片链接的(3个)
    // (一)
    new Thread(new Runnable() {

            @Override
            public void run() {
                for (int i = 1; i < 500; i++) {
                    try {
                        imgDownload.parseImageUrl(i);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        }).start(); 
    
    
        // (二)
        new Thread(new Runnable() {
    
            @Override
            public void run() {
                for (int i = 500; i < 1000; i++) {
                    try {
                        imgDownload.parseImageUrl(i);
                    } catch (Exception e) {
                        e.printStackTrace();
    
                    }
                }
            }
        }).start();
    
        // (三)
        new Thread(new Runnable() {
    
            @Override
            public void run() {
                for (int i = 1000; i < 1500; i++) {
                    try {
                        imgDownload.parseImageUrl(i);
                    } catch (Exception e) {
                        e.printStackTrace();
    
                    }
                }
            }
        }).start();
    
        // 下载图片(5个)
        // (1)
        new Thread(new Runnable() {
            @Override
            public void run() {
                while (true) {// 一直在下载
                    try {
                        imgDownload.downloadimage();
                    } catch (Exception e) {
    
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    
        // (2)
        new Thread(new Runnable() {
    
            @Override
            public void run() {
                while (true) {// 一直在下载
                    try {
                        imgDownload.downloadimage();
                    } catch (Exception e) {
    
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    
        // (3)
        new Thread(new Runnable() {
    
            @Override
            public void run() {
                while (true) {// 一直在下载
                    try {
                        imgDownload.downloadimage();
                    } catch (Exception e) {
    
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    
        // (4)
        new Thread(new Runnable() {
    
            @Override
            public void run() {
                while (true) {// 一直在下载
                    try {
                        imgDownload.downloadimage();
                    } catch (Exception e) {
    
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    
        // (5)
        new Thread(new Runnable() {
    
            @Override
            public void run() {
                while (true) {// 一直在下载
                    try {
                        imgDownload.downloadimage();
                    } catch (Exception e) {
    
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    
    }
    

    }

    // 图片下载类
    class ImageDownload {
    // imageurl的数组
    LinkedList<String> list = new LinkedList<String>();

    // 解析连接
    void parseImageUrl(int page) throws Exception {
        synchronized (this) {
            if (list.size()>100) {
            wait();
        }
        String htmlUrl = "https://www.doutula.com/article/list/?page=" + page;
        Document doc = Jsoup.connect(htmlUrl).get();
        // 获取图片连接
        Elements els = doc.select(".lazy,.image_dtb,.img--responsive");// cssQuery// css选择器// (有 id// tagName// 复合选择器)                      
        Iterator iter = els.iterator();
        while (iter.hasNext()) {
            Element obj = (Element) iter.next();
            String imageUrl = obj.attr("data-original");
            if (!imageUrl.contains(htmlUrl)) {
                continue;
            }
            this.list.add(imageUrl);
        }
        //生产完毕 通知可以下载图片
        notifyAll();
        }
    }
    
    // 下载图片
    void downloadimage() throws Exception {
        synchronized (this) {
            if (this.list.size()<= 0) {
                wait();
            }
        // URL url = new URL(this.list.get(0));
        // this.list.removeFirst();
    
        // 拿一个删除一个用完之后就删除(合二为一)
        String imageUrl =null;
        if (this.list.size()>0) {
            imageUrl = this.list.removeFirst();
        }else{
            return;
        }
        URL url = new URL(imageUrl);
        
        URLConnection connection = url.openConnection();// 创建连接
        connection.connect();// 发送连接
        InputStream in = connection.getInputStream();
        byte[] by = new byte[1024];
        int length = -1;
        // out流
        String[] imageUrlArr = imageUrl.split("/");
        String fileName = "Image/" + imageUrlArr[imageUrlArr.length - 1];
        FileOutputStream fileout = new FileOutputStream(fileName);
        while ((length = in.read(by)) != -1) {// (循环为了防止1024放满不够用)
            // 把流写入本地文件夹里
            fileout.write(by, 0, length);// 截取 防止覆盖不了时候
        }
        fileout.close();
        in.close();
        //通知可以继续生产解析图片
        if (this.list.size()<100) {
             notify();
        }   
        }       
    }
    

    }

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