谁告诉你Java不能做爬虫，我就用它爬取并下载了酷狗TOP500歌曲...

作者：后山悟道人

来源：my.oschina.net/gllfeixiang/blog/2995570

最近，有同学告诉我，Java不能做爬虫，我挺吃惊的，反问了一句：写爬虫跟代码有关系吗？

他陷入了沉思...

本文方法及代码仅供学习使用，不做他用。示例用到了一些库，包括：jsoup、HttpClient、net.sf.json大家可以自行去下载jar包。

# 分析是否能获得TOP500歌单

首先，打开酷狗首页查看酷狗TOP500，说好的500首，怎么就只有22首呢？

是真的只让看这些还是能找到其余的呢，于是，我就看了下这TOP500的链接：https://www.kugou.com/yy/rank/home/1-8888.html?from=rank

可以看的出home后边有个1，难道这是代表第一页的意思？于是我就把1改成2进入，果然进入了第二页， 至此可以知道我们可以在网页里获取这500首的歌单。

# 分析找到真正的mp3下载地址（这个有点绕）

点一个歌曲进入播放页面，使用谷歌浏览器的控制台的Elements，搜一下mp3，很轻松就定位到了MP3的位置。

但是使用java访问的时候爬取的html里却没有该mp3的文件地址，那么这肯定是在该页面的位置使用了js来加载mp3，那么刷新下网页，看网页加载了哪些东西，加载的东西有点多，着重看一下js、php的请求，主要是看里面有没有mp3的地址，分析细节就不用说了。

最终，我在列表的

https://wwwapi.kugou.com/yy/index.php?r=play/getdata&callback=jQuery191027067069941080546_1546235744250&hash=667939C6E784265D541DEEE65AE4F2F8&album_id=0&_=1546235744251

这个请求里发现了mp3的完整地址，

"play_url": "http:\/\/fs.w.kugou.com\/201812311325\/dcf5b6449160903c6ee48035e11434bb\/G128\/M08\/02\/09\/IIcBAFrZqf2ANOadADn94ubOmaU995.mp3",

那这个js是怎么判断是哪首歌的呢，那么只可能是hash这个参数来决定歌曲的，然后到播放页面里找到这个hash的位置，是在下面的js里

var dataFromSmarty = [{"hash":"667939C6E784265D541DEEE65AE4F2F8","timelength":"237051","audio_name":"\u767d\u5c0f\u767d - \u6700\u7f8e\u5a5a\u793c","author_name":"\u767d\u5c0f\u767d","song_name":"\u6700\u7f8e\u5a5a\u793c","album_id":0}],//当前页面歌曲信息
            playType = "search_single";//当前播放
    </script>

在去java爬取该网页，查看能否爬到这个hash，果然，爬取的html里有这段js，到现在mp3的地址也找到了，歌单也找到了，那么下一步就用程序实现就可以了。

# 实现爬取酷狗mp3

先看一下爬取结果：

找到了资源，程序实现就好说了，其中使用到了自己写的几个工具类，自己整理点自己的工具类还是有好处的，以后遇到什么问题就没必要重新写了，直接拿来用就可以了。没什么好说的了，下面直接贴出源码。

SpiderKugou.java

package com.bing.spider;

import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

import com.bing.download.FileDownload;
import com.bing.html.HtmlManage;
import com.bing.http.HttpGetConnect;

import net.sf.json.JSONObject;

public class SpiderKugou {

public static String filePath = "F:/music/";
public static String mp3 = "https://wwwapi.kugou.com/yy/index.php?r=play/getdata&callback=jQuery191027067069941080546_1546235744250&"
            + "hash=HASH&album_id=0&_=TIME";

public static String LINK = "https://www.kugou.com/yy/rank/home/PAGE-8888.html?from=rank";
//"https://www.kugou.com/yy/rank/home/PAGE-23784.html?from=rank";


public static void main(String[] args) throws IOException {

for(int i = 1 ; i < 23 ; i++){
String url = LINK.replace("PAGE", i + "");
            getTitle(url);
//download("https://www.kugou.com/song/mfy6je5.html");
        }
    }

public static String getTitle(String url) throws IOException{
        HttpGetConnect connect = new HttpGetConnect();
String content = connect.connect(url, "utf-8");
        HtmlManage html = new HtmlManage();
        Document doc = html.manage(content);
        Element ele = doc.getElementsByClass("pc_temp_songlist").get(0);
        Elements eles = ele.getElementsByTag("li");
for(int i = 0 ; i < eles.size() ; i++){
            Element item = eles.get(i);
String title = item.attr("title").trim();
String link = item.getElementsByTag("a").first().attr("href");

            download(link,title);
        }
return null;
    }

public static String download(String url,String name) throws IOException{
String hash = "";
        HttpGetConnect connect = new HttpGetConnect();
String content = connect.connect(url, "utf-8");
        HtmlManage html = new HtmlManage();

String regEx = "\"hash\":\"[0-9A-Z]+\"";
// 编译正则表达式
        Pattern pattern = Pattern.compile(regEx);
        Matcher matcher = pattern.matcher(content);
if (matcher.find()) {
            hash = matcher.group();
            hash = hash.replace("\"hash\":\"", "");
            hash = hash.replace("\"", "");
        }

String item = mp3.replace("HASH", hash);
        item = item.replace("TIME", System.currentTimeMillis() + "");

        System.out.println(item);
String mp = connect.connect(item, "utf-8");

        mp = mp.substring(mp.indexOf("(") + 1, mp.length() - 3);

        JSONObject json = JSONObject.fromObject(mp);
String playUrl = json.getJSONObject("data").getString("play_url");


        System.out.print(playUrl + "  ==  ");
        FileDownload down = new FileDownload();
        down.download(playUrl, filePath + name + ".mp3");

        System.out.println(name + "下载完成");
return playUrl;
    }

}

HttpGetConnect.java

package com.bing.http;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.HttpEntity;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.BasicHttpClientConnectionManager;
import org.apache.http.params.HttpParams; 
/**
 * @说明：
 * @author: gaoll
 * @CreateTime:2014-11-13
 * @ModifyTime:2014-11-13
 */
public class HttpGetConnect {

/**
     *  获取html内容
     * @param url
     * @param charsetName  UTF-8、GB2312
     * @return
     * @throws IOException
     */
public static String connect(String url,String charsetName) throws IOException{
BasicHttpClientConnectionManager connManager = new BasicHttpClientConnectionManager();

CloseableHttpClient httpclient = HttpClients.custom()
                .setConnectionManager(connManager)
                .build();
String content = "";

try{
HttpGet httpget = new HttpGet(url);

RequestConfig requestConfig = RequestConfig.custom()
                    .setSocketTimeout(5000)
                    .setConnectTimeout(50000)
                    .setConnectionRequestTimeout(50000)
                    .build();
            httpget.setConfig(requestConfig);
            httpget.setHeader("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
            httpget.setHeader("Accept-Encoding", "gzip,deflate,sdch");
            httpget.setHeader("Accept-Language", "zh-CN,zh;q=0.8");
            httpget.setHeader("Connection", "keep-alive");
            httpget.setHeader("Upgrade-Insecure-Requests", "1");
            httpget.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36");
//httpget.setHeader("Hosts", "www.oschina.net");
            httpget.setHeader("cache-control", "max-age=0");  

CloseableHttpResponse response = httpclient.execute(httpget);

            int status = response.getStatusLine().getStatusCode();
if (status >= 200 && status < 300) {

HttpEntity entity = response.getEntity();
InputStream instream = entity.getContent();
BufferedReader br = new BufferedReader(new InputStreamReader(instream,charsetName));
StringBuffer sbf = new StringBuffer();
String line = null;
while ((line = br.readLine()) != null){
                    sbf.append(line + "\n");
                }

                br.close();
                content = sbf.toString();
            } else {
                content = "";
            }

        }catch(Exception e){
            e.printStackTrace();
        }finally{
            httpclient.close();
        }
//log.info("content is " + content);
return content;
    }
private static Log log = LogFactory.getLog(HttpGetConnect.class);
}

HtmlManage.java

package com.bing.html;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

import com.bing.http.HttpGetConnect;

/**
 * @说明：
 * @author: gaoll
 * @CreateTime:2014-11-13
 * @ModifyTime:2014-11-13
 */
public class HtmlManage {

public Document manage(String html){
        Document doc = Jsoup.parse(html);
return doc;
    }

public Document manageDirect(String url) throws IOException{
        Document doc = Jsoup.connect( url ).get();
return doc;
    }

public List<String> manageHtmlTag(Document doc,String tag ){
        List<String> list = new ArrayList<String>();

        Elements elements = doc.getElementsByTag(tag);
for(int i = 0; i < elements.size() ; i++){
String str = elements.get(i).html();
            list.add(str);
        }
return list;
    }

public List<String> manageHtmlClass(Document doc,String clas ){
        List<String> list = new ArrayList<String>();

        Elements elements = doc.getElementsByClass(clas);
for(int i = 0; i < elements.size() ; i++){
String str = elements.get(i).html();
            list.add(str);
        }
return list;
    }

public List<String> manageHtmlKey(Document doc,String key,String value ){
        List<String> list = new ArrayList<String>();

        Elements elements = doc.getElementsByAttributeValue(key, value);
for(int i = 0; i < elements.size() ; i++){
String str = elements.get(i).html();
            list.add(str);
        }
return list;
    }

private static Log log = LogFactory.getLog(HtmlManage.class);
}

FileDownload.java

package com.bing.download;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;

/**
 * @说明：
 * @author: gaoll
 * @CreateTime:2014-11-20
 * @ModifyTime:2014-11-20
 */
public class FileDownload {

/**
     * 文件下载
     * @param url 链接地址
     * @param path 要保存的路径及文件名
     * @return
     */
public static boolean download(String url,String path){

        boolean flag = false;

        CloseableHttpClient httpclient = HttpClients.createDefault();
        RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(2000)
                .setConnectTimeout(2000).build();

        HttpGet get = new HttpGet(url);
get.setConfig(requestConfig);

        BufferedInputStream in = null;
        BufferedOutputStream out = null;
try{
for(int i=0;i<3;i++){
                CloseableHttpResponse result = httpclient.execute(get);
                System.out.println(result.getStatusLine());
if(result.getStatusLine().getStatusCode() == 200){
in = new BufferedInputStream(result.getEntity().getContent());
                    File file = new File(path);
out = new BufferedOutputStream(new FileOutputStream(file));
                    byte[] buffer = new byte[1024];
                    int len = -1;
while((len = in.read(buffer,0,1024)) > -1){
out.write(buffer,0,len);
                    }
                    flag = true;
break;
                }else if(result.getStatusLine().getStatusCode() == 500){
continue ;
                }
            }

        }catch(Exception e){
            e.printStackTrace();
            flag = false;
        }finally{
get.releaseConnection();
try{
if(in != null){
in.close();
                }
if(out != null){
out.close();
                }
            }catch(Exception e){
                e.printStackTrace();
                flag = false;
            }
        }
return flag;
    }

private static Log log = LogFactory.getLog(FileDownload.class);
}

到这就结束了，有可能有些代码没贴全，主要代码已经差不多，应该可以跑起来，多多指教。

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