把这个类放到和hibernate.cfg.xml一个目录下，编译执行，注意把需要的包(dom4j)引进去

操作xml基本上就这么东西，你仔细看看，很简单的

import java.io.File;
import java.io.FileOutputStream;
import java.util.Iterator;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class HiberCFG {

 /**
  * @param args
  */
 
 public void readXML(){
  try{
   String fname="hibernate.cfg.xml";
   SAXReader reader=new SAXReader();
   Document document=reader.read(new File(fname));
   Element root=document.getRootElement();
   List list=root.selectNodes("/hibernate-configuration/session-factory/property");
   for(Iterator it=list.iterator();it.hasNext();){
    Node node=(Node)it.next();
    if(node.valueOf("@name").equals("hibernate.connection.url")){
     //原url
     String url=node.getText(); 
     System.out.println(url);
     //IP地址前的部分
     String a1=url.substring(0,url.indexOf("//")+2);     
     System.out.println(a1);
     //IP地址后部分
     String a2=url.substring(url.indexOf(":",(url.indexOf("//")+2)),url.length());
     System.out.println(a2);
     
     String newIP="192.168.0.1";
     
     //修改后的url
     String newUrl=a1+newIP+a2;
     System.out.println(newUrl);
     
     //将新url替换
     node.setText(newUrl);
     
     
    }
   }
   
   
   //将文件保存
   String indent="  ";//缩进符号
   boolean newLines=true;// 是否产生新行(即一个元素一行)
   XMLWriter writer=new XMLWriter(new FileOutputStream(fname),new org.dom4j.io.OutputFormat(indent,newLines,"utf-8"));
   writer.write(document);
      writer.flush();
      writer.close();
      System.out.println("成功");
  }
  catch(Exception ex){
   System.out.println("失败");
   ex.printStackTrace();
   
  }
  
 }
 public static void main(String[] args) {
  // TODO Auto-generated method stub
  HiberCFG h=new HiberCFG();
  h.readXML();

 }

}