package com.sinitek.sirm.common.utils;

import java.io.*;

import java.net.URL;

import java.net.URLConnection;

import java.util.*;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

/**

 * java简单web爬虫(网页图片)

 */

public class Main {

    // 地址

    private static final String URL = "http://www.xxx";

    // 获取img标签正则

    private static final String IMGURL_REG = "<img.*src=(.*?)[^>]*?>";

    // 获取src路径的正则

    private static final String IMGSRC_REG = "src\\s*=\\s*\"?(.*?)(\"|>|\\s+)";

    //图片原始路径(如果src里的路径正确则不用)

    private static final String IMG_LUJING = "http://xxx/";

    //下载路径

    private static final String LUJING = "C:/res/";

    public static void main(String[] args) {

        try {

            Main cm=new Main();

            //获得html文本内容

            String HTML = cm.getHtml(URL);

            //获取图片标签

            List<String> imgUrl = cm.getImageUrl(HTML);

            //获取图片src地址

            List<String> imgSrc = cm.getImageSrc(imgUrl);

            //下载图片

            cm.Download(imgSrc);

        }catch (Exception e){

            System.out.println("发生错误");

        }

    }

   //获取HTML内容

    private String getHtml(String url)throws Exception{

        URL url1=new URL(url);

        URLConnection connection=url1.openConnection();

        InputStream in=connection.getInputStream();

        InputStreamReader isr=new InputStreamReader(in);

        BufferedReader br=new BufferedReader(isr);

        String line;

        StringBuffer sb=new StringBuffer();

        while((line=br.readLine())!=null){

            sb.append(line,0,line.length());

            sb.append('\n');

        }

        br.close();

        isr.close();

        in.close();

        return sb.toString();

    }

    //获取ImageUrl地址

    private List<String> getImageUrl(String html){

        Matcher matcher=Pattern.compile(IMGURL_REG).matcher(html);

        List<String>listimgurl=new ArrayList<String>();

        while (matcher.find()){

            listimgurl.add(matcher.group());

        }

        return listimgurl;

    }

    //获取ImageSrc地址

    private List<String> getImageSrc(List<String> listimageurl){

        List<String> listImageSrc=new ArrayList<String>();

        for (String image:listimageurl){

            // 匹配<img>中的src数据

            Matcher m = Pattern.compile(IMGSRC_REG).matcher(image);

            while (m.find()) {

                String a = m.group(1);//获取图片路径

                a = IMG_LUJING+a;//数据拼接

                listImageSrc.add(a);

            }

        }

        return listImageSrc;

    }

    //下载图片

    private void Download(List<String> listImgSrc) {

        try {

            //开始时间

            Date begindate = new Date();

            for (String url : listImgSrc) {

                //开始时间

                Date begindate2 = new Date();

                String imageName = url.substring(url.lastIndexOf("/") + 1, url.length());

                URL uri = new URL(url);

                InputStream in = uri.openStream();

                FileOutputStream fo = new FileOutputStream(new File(LUJING+imageName));//路径

                byte[] buf = new byte[1024];

                int length = 0;

                System.out.println("开始下载:" + url);

                while ((length = in.read(buf, 0, buf.length)) != -1) {

                    fo.write(buf, 0, length);

                }

                in.close();

                fo.close();

                System.out.println(imageName + "下载完成");

                //结束时间

                Date overdate2 = new Date();

                double time = overdate2.getTime() - begindate2.getTime();

                System.out.println("耗时：" + time / 1000 + "s");

            }

            Date overdate = new Date();

            double time = overdate.getTime() - begindate.getTime();

            System.out.println("总耗时：" + time / 1000 + "s");

        } catch (Exception e) {

            System.out.println("下载失败");

        }

    }

}