Java爬虫下载千张美女图片!

java团长

共 2269字,需浏览 5分钟

 ·

2021-02-10 16:44

来源:https://blog.csdn.net/qq_35402412



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=%E7%BE%8E%E5%A5%B3

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=%E7%BE%8E%E5%A5%B3

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 
* @since 0.1.0 */public class SougouImgProcessor { private String url; private SougouImgPipeline pipeline; private List dataList; private List 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 items = (List)((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(){// pipeline.process(this.urlList, word); // 单线程 pipeline.processSync(this.urlList, this.word); // 多线程 } 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 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.
* * @author code4crafter@gmail.com
* @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 data, String word) { long start = System.currentTimeMillis(); for (String picUrl : data) { if (picUrl == null) continue; try { downloadImg(picUrl, word, picUrl); } catch (Exception e) {// e.printStackTrace(); 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 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 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) {// e.printStackTrace(); 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 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 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 nvps = new ArrayList();                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 nvps = new ArrayList();                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");//    try {        StringEntity stringEntity = new StringEntity(jsonString, charset);// 解决中文乱码问题        stringEntity.setContentEncoding(charset);        stringEntity.setContentType("application/json");        httpPost.setEntity(stringEntity);//    } catch (UnsupportedEncodingException e) {//      e.printStackTrace();//    }        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。

PS:如果觉得我的分享不错,欢迎大家随手点赞、在看。
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