简单实现：如何把所有的日志记录到同一个文件中？？？

java.util.logging.Logger

如何把所有的日志记录到同一个文件中？？？  自己做了个简单实现：

package all;
import java.io.IOException;
import java.util.logging.FileHandler;
import java.util.logging.Logger; // <= (1)
import java.util.logging.SimpleFormatter;
import java.util.logging.XMLFormatter;

import fortestlog.Syspath;

public class Loggertest {
    //------------------configure---------
    public static Logger log =null; 
    private static Loggertest loggertestinstance=null;
    String filename="D:\test\1.txt";
    int size=1024*1024;
    int numb=10;
    boolean bappend=true;//追加到一个文件中
    FileHandler fh;
    //------------------configure---------
    
    public Loggertest()
    {
        if(log==null){
            //log=Logger.getLogger(Loggertest.class.getSimpleName());
            //log=Logger.getLogger("");
            log=Logger.getAnonymousLogger();

            try {
                fh = new FileHandler(filename,size,numb,bappend);
                
                //Simple
                //fh.setFormatter(new SimpleFormatter());
                //default
                //fh.setFormatter(new XMLFormatter());     
                log.addHandler(fh);
            

            } catch (SecurityException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } 
        }
    }
    
    public static void dologtask(Object obj,String logcontent)
    {
        if(loggertestinstance==null){
            
            loggertestinstance=new Loggertest();
        }
        loggertestinstance.log.info(obj.getClass().toString()+":"+logcontent);
    }
    public static void dologtask(String logcontent)
    {
        if(loggertestinstance==null){
            
            loggertestinstance=new Loggertest();
        }
        loggertestinstance.log.info(logcontent);
    }
    public static void main(String[] args) {
        
         //Loggertest.dologtask(this,"from Syspath test!!!");
         //call point
         Loggertest.dologtask(new Syspath(),"!!! test  !!!");
         Loggertest.dologtask("::: test  :::");
    }
}