目的

爬取搜狗图片上千张美女图片并下载到本地

准备工作

爬取地址：https://pic.sogou.com/pics?query=美女

分析

打开上面的地址，按F12开发者工具 - NetWork - XHR - 页面往下滑动XHR栏出现请求信息如下：

Request URL ：https://pic.sogou.com/napi/pc/searchList?mode=1&start=48&xml_len=48&query=美女

分析这段请求URL的主要几个参数：

start=48 表示从第48张图片开始检索

xml_len=48 从地48张往后获取48张图片

query=？搜索关键词（例：美女，这里浏览器自动做了转码，不影响我们使用）

点击Respose，找个JSON格式器辅助过去看看。

JSON格式：https://www.bejson.com/

分析Respose返回的信息，可以发现我们想要的图片地址放在 picUrl里，

思路

通过以上分析，不难实现下载方法，思路如下：

1.设置URL请求参数
2.访问URL请求，获取图片地址
3.图片地址存入List
4.遍历List，使用线程池下载到本地

代码

SougouImgProcessor.java 爬取图片类

import com.alibaba.fastjson.JSONObject;
import us.codecraft.webmagic.utils.HttpClientUtils;
import victor.chang.crawler.pipeline.SougouImgPipeline;

import java.util.ArrayList;
import java.util.List;

/**
 * A simple PageProcessor.
 * @author code4crafter@gmail.com <br>
 * @since 0.1.0
 */
public class SougouImgProcessor {

    private String url;
    private SougouImgPipeline pipeline;
    private List<JSONObject> dataList;
    private List<String> urlList;
    private String word;

    public SougouImgProcessor(String url,String word) {
        this.url = url;
        this.word = word;
        this.pipeline = new SougouImgPipeline();
        this.dataList = new ArrayList<>();
        this.urlList = new ArrayList<>();
    }

    public void process(int idx, int size) {
        String res = HttpClientUtils.get(String.format(this.url, idx, size, this.word));
        JSONObject object = JSONObject.parseObject(res);
        List<JSONObject> items = (List<JSONObject>)((JSONObject)object.get("data")).get("items");
        for(JSONObject item : items){
            this.urlList.add(item.getString("picUrl"));
        }
        this.dataList.addAll(items);
    }

    // 下载
    public void pipelineData(){
        // 多线程
        pipeline.processSync(this.urlList, this.word);
    }


    public static void main(String[] args) {
        String url = "https://pic.sogou.com/napi/pc/searchList?mode=1&start=%s&xml_len=%s&query=%s";
        SougouImgProcessor processor = new SougouImgProcessor(url,"美女");

        int start = 0, size = 50, limit = 1000; // 定义爬取开始索引、每次爬取数量、总共爬取数量

        for(int i=start;i<start+limit;i+=size)
            processor.process(i, size);

        processor.pipelineData();

    }

}

SougouImgPipeline.java 图片下载类

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Objects;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Store results in files.<br>
 * @author code4crafter@gmail.com <br>
 * @since 0.1.0
 */
public class SougouImgPipeline {

    private String extension = ".jpg";
    private String path;

    private volatile AtomicInteger suc;
    private volatile AtomicInteger fails;

    public SougouImgPipeline() {
        setPath("E:/pipeline/sougou");
        suc = new AtomicInteger();
        fails = new AtomicInteger();
    }

    public SougouImgPipeline(String path) {
        setPath(path);
        suc = new AtomicInteger();
        fails = new AtomicInteger();
    }

    public SougouImgPipeline(String path, String extension) {
        setPath(path);
        this.extension = extension;
        suc = new AtomicInteger();
        fails = new AtomicInteger();
    }

    public void setPath(String path) {
        this.path = path;
    }

    /**
     * 下载
     * @param url
     * @param cate
     * @throws Exception
     */
    private void downloadImg(String url, String cate, String name) throws Exception {
        String path = this.path + "/" + cate + "/";
        File dir = new File(path);
        if (!dir.exists()) {    // 目录不存在则创建目录
            dir.mkdirs();
        }
        String realExt = url.substring(url.lastIndexOf("."));   // 获取扩展名
        String fileName = name + realExt;
        fileName = fileName.replace("-", "");
        String filePath = path + fileName;
        File img = new File(filePath);
        if(img.exists()){   // 若文件之前已经下载过，则跳过
            System.out.println(String.format("文件%s已存在本地目录",fileName));
            return;
        }

        URLConnection con = new URL(url).openConnection();
        con.setConnectTimeout(5000);
        con.setReadTimeout(5000);
        InputStream inputStream = con.getInputStream();
        byte[] bs = new byte[1024];

        File file = new File(filePath);
        FileOutputStream os = new FileOutputStream(file, true);
        // 开始读取 写入
        int len;
        while ((len = inputStream.read(bs)) != -1) {
            os.write(bs, 0, len);
        }
        System.out.println("picUrl: " + url);
        System.out.println(String.format("正在下载第%s张图片", suc.getAndIncrement()));
    }

    /**
     * 单线程处理
     *
     * @param data
     * @param word
     */
    public void process(List<String> data, String word) {
        long start = System.currentTimeMillis();
        for (String picUrl : data) {
            if (picUrl == null)
                continue;
            try {
                downloadImg(picUrl, word, picUrl);
            } catch (Exception e) {
                fails.incrementAndGet();
            }
        }
        System.out.println("下载成功: " + suc.get());
        System.out.println("下载失败: " + fails.get());
        long end = System.currentTimeMillis();
        System.out.println("耗时：" + (end - start) / 1000 + "秒");
    }


    /**
     * 多线程处理
     *
     * @param data
     * @param word
     */
    public void processSync(List<String> data, String word) {
        long start = System.currentTimeMillis();
        int count = 0;
        ExecutorService executorService = Executors.newCachedThreadPool(); // 创建缓存线程池
        for (int i=0;i<data.size();i++) {
            String picUrl = data.get(i);
            if (picUrl == null)
                continue;
            String name = "";
            if(i<10){
                name="000"+i;
            }else if(i<100){
                name="00"+i;
            }else if(i<1000){
                name="0"+i;
            }
            String finalName = name;
            executorService.execute(() -> {
                try {
                    downloadImg(picUrl, word, finalName);
                } catch (Exception e) {
                    fails.incrementAndGet();
                }
            });
            count++;
        }
        executorService.shutdown();
        try {
            if (!executorService.awaitTermination(60, TimeUnit.SECONDS)) {
                // 超时的时候向线程池中所有的线程发出中断(interrupted)。
                // executorService.shutdownNow();
            }
            System.out.println("AwaitTermination Finished");
            System.out.println("共有URL: "+data.size());
            System.out.println("下载成功: " + suc);
            System.out.println("下载失败: " + fails);

            File dir = new File(this.path + "/" + word + "/");
            int len = Objects.requireNonNull(dir.list()).length;
            System.out.println("当前共有文件： "+len);

            long end = System.currentTimeMillis();
            System.out.println("耗时：" + (end - start) / 1000.0 + "秒");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

    }


    /**
     * 多线程分段处理
     *
     * @param data
     * @param word
     * @param threadNum
     */
    public void processSync2(List<String> data, final String word, int threadNum) {
        if (data.size() < threadNum) {
            process(data, word);
        } else {
            ExecutorService executorService = Executors.newCachedThreadPool();
            int num = data.size() / threadNum;    //每段要处理的数量
            for (int i = 0; i < threadNum; i++) {
                int start = i * num;
                int end = (i + 1) * num;
                if (i == threadNum - 1) {
                    end = data.size();
                }
                final List<String> cutList = data.subList(start, end);
                executorService.execute(() -> process(cutList, word));
            }
            executorService.shutdown();
        }
    }

}

HttpClientUtils.java http请求工具类

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.TrustStrategy;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.ssl.SSLContextBuilder;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.GeneralSecurityException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author code4crafter@gmail.com
 * Date: 17/3/27
 */
public abstract class HttpClientUtils {

    public static Map<String, List<String>> convertHeaders(Header[] headers) {
        Map<String, List<String>> results = new HashMap<String, List<String>>();
        for (Header header : headers) {
            List<String> list = results.get(header.getName());
            if (list == null) {
                list = new ArrayList<String>();
                results.put(header.getName(), list);
            }
            list.add(header.getValue());
        }
        return results;
    }

    /**
     * http的get请求
     * @param url
     */
    public static String get(String url) {
        return get(url, "UTF-8");
    }

    public static Logger logger = LoggerFactory.getLogger(HttpClientUtils.class);

    /**
     * http的get请求
     * @param url
     */
    public static String get(String url, String charset) {
        HttpGet httpGet = new HttpGet(url);
        return executeRequest(httpGet, charset);
    }

    /**
     * http的get请求，增加异步请求头参数
     * @param url
     */
    public static String ajaxGet(String url) {
        return ajaxGet(url, "UTF-8");
    }

    /**
     * http的get请求，增加异步请求头参数
     *
     * @param url
     */
    public static String ajaxGet(String url, String charset) {
        HttpGet httpGet = new HttpGet(url);
        httpGet.setHeader("X-Requested-With", "XMLHttpRequest");
        return executeRequest(httpGet, charset);
    }

    /**
     * @param url
     * @return
     */
    public static String ajaxGet(CloseableHttpClient httpclient, String url) {
        HttpGet httpGet = new HttpGet(url);
        httpGet.setHeader("X-Requested-With", "XMLHttpRequest");
        return executeRequest(httpclient, httpGet, "UTF-8");
    }

    /**
     * http的post请求，传递map格式参数
     */
    public static String post(String url, Map<String, String> dataMap) {
        return post(url, dataMap, "UTF-8");
    }

    /**
     * http的post请求，传递map格式参数
     */
    public static String post(String url, Map<String, String> dataMap, String charset) {
        HttpPost httpPost = new HttpPost(url);
        try {
            if (dataMap != null) {
                List<NameValuePair> nvps = new ArrayList<NameValuePair>();
                for (Map.Entry<String, String> entry : dataMap.entrySet()) {
                    nvps.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
                }
                UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(nvps, charset);
                formEntity.setContentEncoding(charset);
                httpPost.setEntity(formEntity);
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return executeRequest(httpPost, charset);
    }

    /**
     * http的post请求，增加异步请求头参数，传递map格式参数
     */
    public static String ajaxPost(String url, Map<String, String> dataMap) {
        return ajaxPost(url, dataMap, "UTF-8");
    }

    /**
     * http的post请求，增加异步请求头参数，传递map格式参数
     */
    public static String ajaxPost(String url, Map<String, String> dataMap, String charset) {
        HttpPost httpPost = new HttpPost(url);
        httpPost.setHeader("X-Requested-With", "XMLHttpRequest");
        try {
            if (dataMap != null) {
                List<NameValuePair> nvps = new ArrayList<NameValuePair>();
                for (Map.Entry<String, String> entry : dataMap.entrySet()) {
                    nvps.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
                }
                UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(nvps, charset);
                formEntity.setContentEncoding(charset);
                httpPost.setEntity(formEntity);
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return executeRequest(httpPost, charset);
    }

    /**
     * http的post请求，增加异步请求头参数，传递json格式参数
     */
    public static String ajaxPostJson(String url, String jsonString) {
        return ajaxPostJson(url, jsonString, "UTF-8");
    }

    /**
     * http的post请求，增加异步请求头参数，传递json格式参数
     */
    public static String ajaxPostJson(String url, String jsonString, String charset) {
        HttpPost httpPost = new HttpPost(url);
        httpPost.setHeader("X-Requested-With", "XMLHttpRequest");
        
        StringEntity stringEntity = new StringEntity(jsonString, charset);// 解决中文乱码问题
        stringEntity.setContentEncoding(charset);
        stringEntity.setContentType("application/json");
        httpPost.setEntity(stringEntity);
        return executeRequest(httpPost, charset);
    }

    /**
     * 执行一个http请求，传递HttpGet或HttpPost参数
     */
    public static String executeRequest(HttpUriRequest httpRequest) {
        return executeRequest(httpRequest, "UTF-8");
    }

    /**
     * 执行一个http请求，传递HttpGet或HttpPost参数
     */
    public static String executeRequest(HttpUriRequest httpRequest, String charset) {
        CloseableHttpClient httpclient;
        if ("https".equals(httpRequest.getURI().getScheme())) {
            httpclient = createSSLInsecureClient();
        } else {
            httpclient = HttpClients.createDefault();
        }
        String result = "";
        try {
            try {
                CloseableHttpResponse response = httpclient.execute(httpRequest);
                HttpEntity entity = null;
                try {
                    entity = response.getEntity();
                    result = EntityUtils.toString(entity, charset);
                } finally {
                    EntityUtils.consume(entity);
                    response.close();
                }
            } finally {
                httpclient.close();
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }
        return result;
    }

    public static String executeRequest(CloseableHttpClient httpclient, HttpUriRequest httpRequest, String charset) {
        String result = "";
        try {
            try {
                CloseableHttpResponse response = httpclient.execute(httpRequest);
                HttpEntity entity = null;
                try {
                    entity = response.getEntity();
                    result = EntityUtils.toString(entity, charset);
                } finally {
                    EntityUtils.consume(entity);
                    response.close();
                }
            } finally {
                httpclient.close();
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }
        return result;
    }

    /**
     * 创建 SSL连接
     */
    public static CloseableHttpClient createSSLInsecureClient() {
        try {
            SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(new TrustStrategy() {
                @Override
                public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException {
                    return true;
                }
            }).build();
            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext, new HostnameVerifier() {
                @Override
                public boolean verify(String hostname, SSLSession session) {
                    return true;
                }
            });
            return HttpClients.custom().setSSLSocketFactory(sslsf).build();
        } catch (GeneralSecurityException ex) {
            throw new RuntimeException(ex);
        }
    }
}

运行

由于网络等原因，我们发现并不能全部下载成功，不过可以多次运行尝试，可以实现较高的下载成功率。



666，厉害了。。