jsoup 爬取案例 jsoup

package jousp;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

public class JSoupP {

	public static void main(String[] args) throws Exception {
		Document document = Jsoup.connect("https://book.douban.com").get();
		Elements elements = document.getElementsByTag("img");
		Element element = elements.get(0);
		String url  = element.attr("src");
		URL url1 = new URL(url);
		HttpURLConnection connection = (HttpURLConnection)url1.openConnection();
		connection.setRequestMethod("GET");
		connection.setConnectTimeout(5*1000);
		//获得图片的输入流
		InputStream inputStream = connection.getInputStream();
		byte data[] = readInputStream(inputStream);
		//定义图片位置
		File imageFile = new File("D://BeautyGirl.jpg");  
		//定义输出流
		FileOutputStream outStream = new FileOutputStream(imageFile);
		outStream.write(data);
		outStream.flush();
		outStream.close();
	/*	public static void main(String[] args) throws Exception {  
	        //new一个URL对象  
	        URL url = new URL("http://img.hexun.com/2011-06-21/130726386.jpg");  
	        //打开链接  
	        HttpURLConnection conn = (HttpURLConnection)url.openConnection();  
	        //设置请求方式为"GET"  
	        conn.setRequestMethod("GET");  
	        //超时响应时间为5秒  
	        conn.setConnectTimeout(5 * 1000);  
	        //通过输入流获取图片数据  
	        InputStream inStream = conn.getInputStream();  
	        //得到图片的二进制数据，以二进制封装得到数据，具有通用性  
	        byte[] data = readInputStream(inStream);  
	        //new一个文件对象用来保存图片，默认保存当前工程根目录  
	        File imageFile = new File("BeautyGirl.jpg");  
	        //创建输出流  
	        FileOutputStream outStream = new FileOutputStream(imageFile);  
	        //写入数据  
	        outStream.write(data);  
	        //关闭输出流  
	        outStream.close();  
	    }  */
		
	}
	public static byte[] readInputStream(InputStream inStream) throws Exception{  
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();  
        //创建一个Buffer字符串  
        byte[] buffer = new byte[1024];  
        //每次读取的字符串长度，如果为-1，代表全部读取完毕  
        int len = 0;  
        //使用一个输入流从buffer里把数据读取出来  
        while( (len=inStream.read(buffer)) != -1 ){  
            //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度  
            outStream.write(buffer, 0, len);  
        }  
        //关闭输入流  
        inStream.close();  
        //把outStream里的数据写入内存  
        return outStream.toByteArray();  
    }  


}