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);
		//獲得圖片的輸入流
		InputStream inputStream = connection.getInputStream();
		byte data[] = readInputStream(inputStream);
		//定義圖片位置
		File imageFile = new File("D://BeautyGirl.jpg");  
		//定義輸出流
		FileOutputStream outStream = new FileOutputStream(imageFile);
		outStream.write(data);
		outStream.flush();
		outStream.close();
	/*	public static void main(String[] args) throws Exception {  
	        //new一個URL對象  
	        URL url = new URL("http://img.hexun.com/2011-06-21/130726386.jpg");  
	        //打開鏈接  
	        HttpURLConnection conn = (HttpURLConnection)url.openConnection();  
	        //設置請求方式爲"GET"  
	        conn.setRequestMethod("GET");  
	        //超時響應時間爲5秒  
	        conn.setConnectTimeout(5 * 1000);  
	        //通過輸入流獲取圖片數據  
	        InputStream inStream = conn.getInputStream();  
	        //得到圖片的二進制數據，以二進制封裝得到數據，具有通用性  
	        byte[] data = readInputStream(inStream);  
	        //new一個文件對象用來保存圖片，默認保存當前工程根目錄  
	        File imageFile = new File("BeautyGirl.jpg");  
	        //創建輸出流  
	        FileOutputStream outStream = new FileOutputStream(imageFile);  
	        //寫入數據  
	        outStream.write(data);  
	        //關閉輸出流  
	        outStream.close();  
	    }  */
		
	}
	public static byte[] readInputStream(InputStream inStream) throws Exception{  
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();  
        //創建一個Buffer字符串  
        byte[] buffer = new byte[1024];  
        //每次讀取的字符串長度，如果爲-1，代表全部讀取完畢  
        int len = 0;  
        //使用一個輸入流從buffer裏把數據讀取出來  
        while( (len=inStream.read(buffer)) != -1 ){  
            //用輸出流往buffer裏寫入數據，中間參數代表從哪個位置開始讀，len代表讀取的長度  
            outStream.write(buffer, 0, len);  
        }  
        //關閉輸入流  
        inStream.close();  
        //把outStream裏的數據寫入內存  
        return outStream.toByteArray();  
    }  


}