Socket广播

       //import package

       import java.net.*;

       //define variable

       byte[] buffer;

       //init socket

       InetAddress group = InetAddress.getByName("255.255.255.255");

       MulticastSocket socket = new MulticastSocket();

       DatagramPacket packet = new DatagramPacket(buffer, buffer.length, group, 50000);

       //send data

       socket.send(packet1);

读取XML

       //import package

       import javax.xml.parsers.*;

       import org.w3c.dom.*;

       //define variable

       DocumentBuilder db=null;

       Document doc=null;

       //get document builder

       db=DocumentBuilderFactory.newInstance().newDocumentBuilder();

       //parse xml file

       doc=db.parse(file);

       //format xml file content

       doc.normalize();

       //get node value

       element=doc.getDocumentElement();

       element=(Element)element.getElementsByTagName(key).item(0);

       nodeValue=element.getFirstChild().getNodeValue();

得到类名/方法名

       exp=new Throwable();

       //get class name

       exp.getStackTrace()[0].getClassName();

       //get method name

       exp.getStackTrace()[0].getMethodName();

       //get file name

       return exp.getStackTrace()[0].getFileName();