基於SpringBoot的Java爬蟲項目-京東商品頁
本文是在學習java爬蟲時,跟着視頻做的一個小項目,本文會着重介紹其中會遇到的問題及重要代碼實現。
一. 爬取(部分)效果圖
具體信息:
爬取圖片:
二.遇到的各種BUG
導入到數據庫中的中文文字符亂碼:
解決方法:在數據庫名字後面加上:
?useUnicode=true&serverTimezone=Asia/Shanghai&characterEncoding=utf-8&nullCatalogMeansCurrent=true
在做debug測試時出現:
解決方法:
觀察項目的jdk版本和congratulation中的jdk版本是否一致
在導入依賴時,Sping的包版本要一致,不然會出現很多問題
數據庫版本不宜太高:
版本6以下可以用用5.1.8版本
高版本的話還要在application.properties中修改成com.mysql.cj.jdbc.Driver
在請求京東頁面時,最起碼要加個請求頭,不然也太看不起爬蟲了…
httpGet.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.100 Safari/537.36");
最新的User-Agent去京東上看看
三. 項目目錄結構
四. 具體代碼詳解
4.1 配置文件添加依賴
在pom.xml中
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>cn.itcast</groupId>
<artifactId>itcast-crawler-jd</artifactId>
<version>1.0-SNAPSHOT</version>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>8</source>
<target>8</target>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<!--SpringMVC-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>2.2.2.RELEASE</version>
</dependency>
<!--SpringData Jpa-->
<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-jpa -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
<version>2.2.2.RELEASE</version>
</dependency>
<!--MySQL連接包-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.8</version>
</dependency>
<!-- HttpClient -->
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.2</version>
</dependency>
<!--Jsoup-->
<dependency>
<groupId>org.jsoup</groupId>
<artifactId>jsoup</artifactId>
<version>1.10.3</version>
</dependency>
<!--工具包-->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.4</version>
</dependency>
</dependencies>
</project>
4.2 application.properties文件
#DB Configuration:
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/day17?useUnicode=true&serverTimezone=Asia/Shanghai&characterEncoding=utf-8&nullCatalogMeansCurrent=true
spring.datasource.username=數據庫用戶名稱
spring.datasource.password=數據庫密碼
#JPA Configuration:
spring.jpa.database=MySQL
spring.jpa.show-sql=true
spring.jpa.open-in-view=false
4.3 dao目錄下ItemDao類
這個文件就是對數據庫進行操作的信息,具體的可以查看JpaRepository類源碼。
JpaRepository <Item,Long>中的Item就是需要存儲數據所放的參數,在這裏非常的方便,只需要放入一個對象就可以存入數據庫。
package cn.itcast.jd.dao;
import cn.itcast.jd.pojo.Item;
import org.springframework.data.jpa.repository.JpaRepository;
public interface ItemDao extends JpaRepository<Item,Long> {
}
4.4 jd.pojo目錄下Item類
這個類其實就是用於存放在數據庫中
package cn.itcast.jd.pojo;
import javax.persistence.*;
import java.util.Date;
@Entity
@Table(name = "jd_item")
public class Item {
//主鍵
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
//標準產品單位(商品集合)
private Long spu;
//庫存量單位(最小品類單元)
private Long sku;
//商品標題
private String title;
//商品價格
private Double price;
//商品圖片
private String pic;
//商品詳情地址
private String url;
//創建時間
private Date created;
//更新時間
private Date updated;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public Long getSpu() {
return spu;
}
public void setSpu(Long spu) {
this.spu = spu;
}
public Long getSku() {
return sku;
}
public void setSku(Long sku) {
this.sku = sku;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public Double getPrice() {
return price;
}
public void setPrice(Double price) {
this.price = price;
}
public String getPic() {
return pic;
}
public void setPic(String pic) {
this.pic = pic;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public Date getCreated() {
return created;
}
public void setCreated(Date created) {
this.created = created;
}
public Date getUpdated() {
return updated;
}
public void setUpdated(Date updated) {
this.updated = updated;
}
}
4.5 service目錄下的ItemServiceImpl和ItemService
ItemService接口:這裏定義了接口用於對數據庫進行操作。
package cn.itcast.jd.service;
import cn.itcast.jd.pojo.Item;
import java.util.List;
public interface ItemService {
/**
* 保存商品
* @param item
*/
public void save(Item item);
/**
* 根據條件查詢商品
* @param item
* @return
*/
public List<Item> findAll(Item item);
}
ItemServiceImpl類:接口的實現類,這個類其實就是利用了ItemDao這個類的方法。
package cn.itcast.jd.service.impl;
import cn.itcast.jd.dao.ItemDao;
import cn.itcast.jd.pojo.Item;
import cn.itcast.jd.service.ItemService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Example;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import java.util.List;
@Service
public class ItemServiceImpl implements ItemService {
@Autowired
private ItemDao itemDao;
@Override
@Transactional
public void save(Item item) {
this.itemDao.save(item);
}
@Override
public List<Item> findAll(Item item) {
//聲明查詢條件
Example<Item> example = Example.of(item);
//根據查詢條件進行查詢數據
List<Item> list = this.itemDao.findAll(example);
return list;
}
}
4.6 工具類:HttpUtils
這個類包含了解析HTML和下載圖片的方法
package cn.itcast.jd.util;
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;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.util.EntityUtils;
import org.springframework.stereotype.Component;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.UUID;
@Component
public class HttpUtils {
private PoolingHttpClientConnectionManager cm;
public HttpUtils() {
this.cm = new PoolingHttpClientConnectionManager();
//設置最大連接數
this.cm.setMaxTotal(100);
//設置每個主機的最大連接數
this.cm.setDefaultMaxPerRoute(10);
}
/**
* 根據請求地址下載頁面數據
*
* @param url
* @return 頁面數據
*/
public String doGetHtml(String url) {
//獲取HttpClient對象
CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(this.cm).build();
//創建httpGet請求對象,設置url地址
HttpGet httpGet = new HttpGet(url);
httpGet.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.100 Safari/537.36");
//設置請求信息
httpGet.setConfig(this.getConfig());
CloseableHttpResponse response = null;
try {
//使用HttpClient發起請求,獲取響應
response = httpClient.execute(httpGet);
//解析響應,返回結果
if (response.getStatusLine().getStatusCode() == 200) {
//判斷響應體Entity是否不爲空,如果不爲空就可以使用EntityUtils
if (response.getEntity() != null) {
String content = EntityUtils.toString(response.getEntity(), "utf8");
return content;
}
}
} catch (IOException e) {
e.printStackTrace();
} finally {
//關閉response
if (response != null) {
try {
response.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
//返回空串
return "";
}
/**
* 下載圖片
*
* @param url
* @return 圖片名稱
*/
public String doGetImage(String url) {
//獲取HttpClient對象
CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(this.cm).build();
//創建httpGet請求對象,設置url地址
HttpGet httpGet = new HttpGet(url);
httpGet.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.100 Safari/537.36");
//設置請求信息
httpGet.setConfig(this.getConfig());
CloseableHttpResponse response = null;
try {
//使用HttpClient發起請求,獲取響應
response = httpClient.execute(httpGet);
//解析響應,返回結果
if (response.getStatusLine().getStatusCode() == 200) {
//判斷響應體Entity是否不爲空
if (response.getEntity() != null) {
//下載圖片
//獲取圖片的後綴
String extName = url.substring(url.lastIndexOf("."));
//創建圖片名,重命名圖片
String picName = UUID.randomUUID().toString() + extName;
//下載圖片
//聲明OutPutStream
OutputStream outputStream = new FileOutputStream(new File("C:\\Users\\張振東\\Pictures\\爬蟲\\" + picName));
response.getEntity().writeTo(outputStream);
//返回圖片名稱
return picName;
}
}
} catch (IOException e) {
e.printStackTrace();
} finally {
//關閉response
if (response != null) {
try {
response.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
//如果下載失敗,返回空串
return "";
}
//設置請求信息
private RequestConfig getConfig() {
RequestConfig config = RequestConfig.custom()
.setConnectTimeout(1000) //創建連接的最長時間
.setConnectionRequestTimeout(500) // 獲取連接的最長時間
.setSocketTimeout(10000) //數據傳輸的最長時間
.build();
return config;
}
}
4.7 ItemTask類
實現爬取功能的主要類:
package cn.itcast.jd.task;
import cn.itcast.jd.pojo.Item;
import cn.itcast.jd.service.ItemService;
import cn.itcast.jd.util.HttpUtils;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import java.util.Date;
import java.util.List;
@Component
public class ItemTask {
@Autowired
private HttpUtils httpUtils;
@Autowired
private ItemService itemService;
private static final ObjectMapper MAPPER = new ObjectMapper();
//當下載任務完成後,間隔多長時間進行下一次的任務。
@Scheduled(fixedDelay = 100 * 1000)
public void itemTask() throws Exception {
//聲明需要解析的初始地址
String url = "https://search.jd.com/Search?keyword=%E6%89%8B%E6%9C%BA&enc=utf-8&qrst=1&rt=1&stop=1&vt=2&wq" +
"=%E6%89%8B%E6%9C%BA&cid2=653&cid3=655&s=113&click=0&page=";
//按照頁面對手機的搜索結果進行遍歷解析
for (int i = 1; i < 10; i = i + 2) {
String html = httpUtils.doGetHtml(url + i);
//解析頁面,獲取商品數據並存儲
this.parse(html);
}
System.out.println("手機數據抓取完成!");
}
//解析頁面,獲取商品數據並存儲
private void parse(String html) throws Exception {
//解析html獲取Document
Document doc = Jsoup.parse(html);
//獲取spu信息
Elements spuEles = doc.select("div#J_goodsList > ul > li");
for (Element spuEle : spuEles) {
//獲取spu
long spu = Long.parseLong(spuEle.attr("data-spu"));
//獲取sku信息
Elements skuEles = spuEle.select("li.ps-item");
for (Element skuEle : skuEles) {
//獲取sku
long sku = Long.parseLong(skuEle.select("[data-sku]").attr("data-sku"));
//根據sku查詢商品數據
Item item = new Item();
item.setSku(sku);
List<Item> list = this.itemService.findAll(item);
if (list.size() > 0) {
//如果商品存在,就進行下一個循環,該商品不保存,因爲已存在
continue;
}
//設置商品的spu
item.setSpu(spu);
//獲取商品的詳情的url
String itemUrl = "https://item.jd.com/" + sku + ".html";
item.setUrl(itemUrl);
//獲取商品的圖片
String picUrl = "https:" + skuEle.select("img[data-sku]").first().attr("data-lazy-img");
picUrl = picUrl.replace("/n9/", "/n1/");
if (picUrl.equals("https:")){
break;
}
String picName = this.httpUtils.doGetImage(picUrl);
item.setPic(picName);
//獲取商品的價格
String priceJson = this.httpUtils.doGetHtml("https://p.3.cn/prices/mgets?skuIds=J_" + sku);
double price = MAPPER.readTree(priceJson).get(0).get("p").asDouble();
item.setPrice(price);
//獲取商品的標題
String itemInfo = this.httpUtils.doGetHtml(item.getUrl());
String title = Jsoup.parse(itemInfo).select("div.sku-name").text();
item.setTitle(title);
item.setCreated(new Date());
item.setUpdated(item.getCreated());
//保存商品數據到數據庫中
this.itemService.save(item);
}
}
}
}
END!!! 長路漫漫,JAVA爲伴!!!