import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.HashMap;
import com.sun.jna.Native;
import com.sun.jna.platform.win32.WinDef.UINT_PTR;
import com.sun.jna.win32.*;

public class MyWallpaper {
	public static void main(String[] argc) throws ParserConfigurationException, SAXException, IOException
	{
		MyWallpaper wallpaper = new MyWallpaper();
		
		do{
		String path = wallpaper.getThePath();
		wallpaper.downLoadWallpaper(path);
		wallpaper.settingWallpaper();
		}while(wallpaper.isConnect()!=true);
	}
	
	public interface SPI extends StdCallLibrary {

	      
	      long SPI_SETDESKWALLPAPER = 20;
	      long SPIF_UPDATEINIFILE = 0x01;
	      long SPIF_SENDWININICHANGE = 0x02;

	      SPI INSTANCE = (SPI) Native.loadLibrary("user32", SPI.class, new HashMap<Object, Object>() {
	         {
	            put(OPTION_TYPE_MAPPER, W32APITypeMapper.UNICODE);
	            put(OPTION_FUNCTION_MAPPER, W32APIFunctionMapper.UNICODE);
	         }
	      });

	      boolean SystemParametersInfo(
	          UINT_PTR uiAction,
	          UINT_PTR uiParam,
	          String pvParam,
	          UINT_PTR fWinIni
	        );
	  }
	
	public boolean isConnect() throws IOException
	{
		Runtime runtime = Runtime.getRuntime();
		Process process = runtime.exec("ping www.baidu.com");
		InputStream is = process.getInputStream();
		InputStreamReader isr = new InputStreamReader(is);
		BufferedReader br = new BufferedReader(isr);
		if(br.readLine()==null)
		{
			//System.out.println("The network is wrong!");
			return false;
		}
		else
		{
			//System.out.println("The network is well");
			return true;
		}
	}
	
	public String getThePath() throws ParserConfigurationException, SAXException, IOException
	{
		//getting the path of the bing jpg picture via analysis xml
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); 
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("http://www.bing.com/HPImageArchive.aspx?format=xml&idx=0&n=8");
		document.normalize(); 
		String relativePath =document.getElementsByTagName("url").item(0).getTextContent();
		String path ="http://www.bing.com/"+relativePath;
		return path;
	}
	
	public void downLoadWallpaper(String path) throws IOException
	{
		//download the jpg file
		URL url = new URL(path);
		DataInputStream dis = new DataInputStream(url.openStream());
		FileOutputStream fos = new FileOutputStream(new File("C:\\wallpaper.jpg"));
		byte[] buffer = new byte[1024];
		int length;
		while((length=dis.read(buffer))>0)
		{	
			fos.write(buffer,0,length);
		}
				
			dis.close();
			fos.close();
	}
	
	public void settingWallpaper()
	{
		 String localpath = "C:\\wallpaper.jpg";

	     SPI.INSTANCE.SystemParametersInfo(
	          new UINT_PTR(SPI.SPI_SETDESKWALLPAPER), 
	          new UINT_PTR(0), 
	          localpath, 
	          new UINT_PTR(SPI.SPIF_UPDATEINIFILE | SPI.SPIF_SENDWININICHANGE));
	}
}