最近在做ETL的项目，其中肯定要有数据，才能在各个工具之间抽取、转存、加载。按照天亮爬虫项目上的讲解，对网易之家的贷款机构进行了抓取。大致模块分为四部分：抓取模块、实体类、工具类、控制类。现在把相关的代码大致记录一遍，以防遗忘。
首先定义一个定义两个工具类，第一个工具类负责将将后期抓取的数据写入到一个文件里保存：
import java.io.File; import java.io.FileOutputStream; import java.io.IOException;/***文件读写类*/ public class IOUtil {public static void writeFile(String filePath, String value, String encoding) {FileOutputStream fos = null;try {fos = new FileOutputStream(new File(filePath));fos.write(value.getBytes(encoding));fos.close();} catch (Exception e) {e.printStackTrace();} finally {if (fos != null) {try {fos.close();} catch (IOException e) {e.printStackTrace();}}}}public static void main(String[] args) {String filePath = "test.txt";String value = "中国人民万岁,hello world,123";String encoding = "utf-8";IOUtil.writeFile(filePath, value, encoding);System.out.println("done!");} }
其次一个工具类是对抓取到的数据进行解析，因为后期抓取到的数据是json格式的，需要模板进行解析：
import java.util.Iterator; import org.json.simple.JSONArray; import org.json.simple.JSONObject; import org.json.simple.JSONValue;/*** json解析工具类* */ public class JsonOperatorUtil {public static JSONObject toJSONObject(String str) {return (JSONObject) JSONValue.parse(str);}public static JSONArray toJSONArray(String str) {return (JSONArray) JSONValue.parse(str);}public static void main(String[] args) {String str = "[{\"one\":1,\"two\":\"2\"}]"; // JSONObject jsonObject = JsonOperatorUtil.toJSONObject(str);JSONArray jsonObject = JsonOperatorUtil.toJSONArray(str);Iterator<JSONObject> iterator=jsonObject.iterator();while(iterator.hasNext()){System.out.println(iterator.next());}} }
一个设置爬虫的层级类
/**设置任务的级别 */ public enum TaskLevel {HIGH, MIDDLE, LOW }
接下来是一个爬虫实现接口类
public interface ICrawler {public CrawlResultPojo crawl(UrlPojo urlPojo); }
在接口的实现上采取了两种实现方法，一种是利用HttpClient工具对数据抓取，另外一种直接用传统的HttpConnect来对数据进行抓取。
第一种方法的实现：
import java.io.BufferedReader; import java.io.InputStreamReader; import java.net.HttpURLConnection; public class HttpUrlConnectionCrawlerImpl implements ICrawler {@Overridepublic CrawlResultPojo crawl(UrlPojo urlPojo) {CrawlResultPojo crawlResultPojo = new CrawlResultPojo();if (urlPojo == null || urlPojo.getUrl() == null) {crawlResultPojo.setSuccess(false);crawlResultPojo.setPageContent(null);return crawlResultPojo;}StringBuilder stringBuilder = new StringBuilder();HttpURLConnection httpURLConnection = urlPojo.getConnection();if (httpURLConnection != null) {BufferedReader br = null;String line = null;try {br = new BufferedReader(new InputStreamReader(httpURLConnection.getInputStream(),"gb2312"));while ((line = br.readLine()) != null) { // System.out.println(line);;stringBuilder.append(line+"\n");}crawlResultPojo.setSuccess(true);crawlResultPojo.setPageContent(stringBuilder.toString());} catch (Exception e) {e.printStackTrace();} finally {try {if (br != null) {br.close();}} catch (Exception e) {e.printStackTrace();System.out.println("done!");}}}return crawlResultPojo;}}
Httpclient实现类：
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.net.URI; import java.util.HashMap; import java.util.Map; import java.util.Map.Entry;import org.apache.http.HttpEntity; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpUriRequest; import org.apache.http.client.methods.RequestBuilder; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClients;import com.ztl.simple.iface.crawl.ICrawler; import com.ztl.simple.pojos.CrawlResultPojo; import com.ztl.simple.pojos.UrlPojo;public class HttpClientCrawlerImpl implements ICrawler {public CloseableHttpClient httpclient = HttpClients.custom().build();@Overridepublic CrawlResultPojo crawl(UrlPojo urlPojo) {if (urlPojo == null) {return null;}CrawlResultPojo crawlResultPojo = new CrawlResultPojo();CloseableHttpResponse response1 = null;BufferedReader br = null;try {HttpGet httpget = new HttpGet(urlPojo.getUrl());response1 = httpclient.execute(httpget);HttpEntity entity = response1.getEntity();InputStreamReader isr = new InputStreamReader(entity.getContent(),"utf-8");br = new BufferedReader(isr);String line = null;StringBuilder stringBuilder = new StringBuilder();while ((line = br.readLine()) != null) {stringBuilder.append(line + "\n");}crawlResultPojo.setSuccess(true);crawlResultPojo.setPageContent(stringBuilder.toString());return crawlResultPojo;} catch (Exception e) {e.printStackTrace();crawlResultPojo.setSuccess(false);} finally {if (response1 != null) {try {response1.close();} catch (IOException e1) {e1.printStackTrace();}}if (br != null) {try {br.close();} catch (IOException e1) {e1.printStackTrace();}}}return crawlResultPojo;}/*** 传入加入参数post参数的url pojo*/public CrawlResultPojo crawl4Post(UrlPojo urlPojo) {if (urlPojo == null) {return null;}CrawlResultPojo crawlResultPojo = new CrawlResultPojo();CloseableHttpResponse response1 = null;BufferedReader br = null;try {RequestBuilder rb = RequestBuilder.post().setUri(new URI(urlPojo.getUrl()));;// .addParameter("IDToken1",// "username").addParameter("IDToken2", "password").build(); Map<String, Object> parasMap = urlPojo.getParasMap();if (parasMap != null) {for (Entry<String, Object> entry : parasMap.entrySet()) {rb.addParameter(entry.getKey(), entry.getValue().toString());}}HttpUriRequest httpRequest = rb.build();response1 = httpclient.execute(httpRequest);HttpEntity entity = response1.getEntity();InputStreamReader isr = new InputStreamReader(entity.getContent(),"utf-8");br = new BufferedReader(isr);String line = null;StringBuilder stringBuilder = new StringBuilder();while ((line = br.readLine()) != null) {stringBuilder.append(line + "\n");}crawlResultPojo.setSuccess(true);crawlResultPojo.setPageContent(stringBuilder.toString());return crawlResultPojo;} catch (Exception e) {e.printStackTrace();crawlResultPojo.setSuccess(false);} finally {if (response1 != null) {try {response1.close();} catch (IOException e1) {e1.printStackTrace();}}if (br != null) {try {br.close();} catch (IOException e1) {e1.printStackTrace();}}}return crawlResultPojo;}public static void main(String[] args) throws Exception {HttpClientCrawlerImpl httpClientCrawlerImpl = new HttpClientCrawlerImpl();String url = "http://www.wangdaizhijia.com/front_select-plat";UrlPojo urlPojo = new UrlPojo(url);Map<String, Object> parasMap = new HashMap<String, Object>();int max_page_number = 1000;parasMap.put("currPage", 30);parasMap.put("params", "");parasMap.put("sort", 0);urlPojo.setParasMap(parasMap);CrawlResultPojo resultPojo = httpClientCrawlerImpl.crawl4Post(urlPojo);if (resultPojo != null) {System.out.println(resultPojo);}} }
最后是抓取控制类：
import java.util.HashMap; import java.util.HashSet; import java.util.Map; import java.util.Set;import org.json.simple.JSONArray; import org.json.simple.JSONObject;import com.ztl.simple.impl.crawl.HttpClientCrawlerImpl; import com.ztl.simple.pojos.CrawlResultPojo; import com.ztl.simple.pojos.UrlPojo; import com.ztl.simple.utils.IOUtil; import com.ztl.simple.utils.JsonOperatorUtil;/*** 网易贷抓取管理器* * @author zel* */ public class WangYiDaiCrawlManager {public static HttpClientCrawlerImpl httpClientCrawlerImpl = new HttpClientCrawlerImpl();public static String[] column_key = { "platName", "locationAreaName","locationCityName", "platUrl" };public static int item_count = 0;private static CrawlResultPojo crawlOnePage(UrlPojo urlPojo) {CrawlResultPojo resultPojo = httpClientCrawlerImpl.crawl4Post(urlPojo);return resultPojo;}public static String parserOnePage(String jsonStr) {// 解析该jsonJSONObject jsonObj = JsonOperatorUtil.toJSONObject(jsonStr);JSONArray jsonArray = JsonOperatorUtil.toJSONArray(jsonObj.get("list").toString());StringBuilder stringBuilder = new StringBuilder();for (Object json : jsonArray) {JSONObject itemJson = (JSONObject) json;for (String column : column_key) {stringBuilder.append(itemJson.get(column) + "\t");}stringBuilder.append("\n");item_count++;}return stringBuilder.toString();}public static void processWangYiDai(String url, int max_page_number,String filePath) {// 存储所有的抓取条目StringBuilder all_items = new StringBuilder();UrlPojo urlPojo = new UrlPojo(url);Map<String, Object> parasMap = new HashMap<String, Object>();int have_download_page_count = 0;Set<String> uniqSet = new HashSet<String>();for (int pageNumber = 1; pageNumber <= max_page_number; pageNumber++) {parasMap.put("currPage", pageNumber);parasMap.put("params", "");parasMap.put("sort", 0);urlPojo.setParasMap(parasMap);CrawlResultPojo resultPojo = crawlOnePage(urlPojo);if (uniqSet.contains(resultPojo.getPageContent())) {System.out.println("碰到重复，代表已抓取完成!");break;} else {uniqSet.add(resultPojo.getPageContent());}if (resultPojo != null) {String content = resultPojo.getPageContent();String page_items = parserOnePage(content);all_items.append(page_items);have_download_page_count++;}}System.out.println("all items size---" + item_count);System.out.println("已经下载了---" + have_download_page_count);IOUtil.writeFile(filePath, all_items.toString(), "utf-8");System.out.println("save successfully~");}public static void main(String[] args) {String url = "http://www.wangdaizhijia.com/front_select-plat";int max_page_number = 1000;String fileName = "网易贷_数据集1.txt";processWangYiDai(url, max_page_number, fileName);System.out.println("done!");} }
