最近接触了下java的爬虫，文本信息爬完了，就想看看图片怎么爬，于是就研究了一下，案例爬取的是CSDN的今日推荐的图片

Jsoup + HttpClients来实现爬虫

所需pom依赖

		<!-- https://mvnrepository.com/artifact/org.jsoup/jsoup -->
		<dependency>
			<groupId>org.jsoup</groupId>
			<artifactId>jsoup</artifactId>
			<version>1.11.3</version>
		</dependency>
		        <!-- 文件下载 -->
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.5</version>
        </dependency>
                <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.5</version>
        </dependency>
爬取代码，定义和思路都写在注释里面的了
package com.xy.test;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.io.FileUtils;
import org.apache.http.HttpEntity;
import org.apache.http.client.ClientProtocolException;
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.util.EntityUtils;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
public class Test2 {
	 public static void main(String[] args) throws ClientProtocolException, IOException {
	        // 创建httpclient实例
	        CloseableHttpClient httpclient = HttpClients.createDefault();
	        // 创建httpget实例
	        // 执行get请求
	        CloseableHttpResponse response = httpclient.execute(httpget);
	        HttpEntity entity = response.getEntity();
	        // 获取返回实体
	        String content = EntityUtils.toString(entity, "utf-8");
	        // 解析网页 得到文档对象
	        Document doc = Jsoup.parse(content);
	        // 获取指定的 <img />
	        Elements elements = doc.select(".img_box img");
	        for (int i = 0; i < 15; i++) {
	            Element element = elements.get(i);
	            // 获取 <img /> 的 src
	            String url = element.attr("src");
	            // 再发请求最简单了，并由于该链接是没有 https:开头的，得人工补全 ✔
	            HttpGet PicturehttpGet = new HttpGet(url);
	            System.out.println("asdasd:"+PicturehttpGet);
	            CloseableHttpResponse pictureResponse = httpclient.execute(PicturehttpGet);
	            HttpEntity pictureEntity = pictureResponse.getEntity();
	            InputStream inputStream = pictureEntity.getContent();
	            // 使用 common-io 下载图片到本地，注意图片名不能重复 ✔
	            FileUtils.copyToFile(inputStream, new File("D://img//" + i + ".jpg"));
	            pictureResponse.close(); // pictureResponse关闭
	        response.close(); // response关闭
	        httpclient.close(); // httpClient关闭
效果如下：