求助，高手们我调试不出以下程序片段

[redocean]

package first;
import sun.net.*;
import java.awt.*;
import java.io.*;
public class download {
Filer filer1=new Filer(this,"文件下载到.....",Filer.SAVE);
public download(String filename,String directory) {
try
{
if(directory.equals(""))
{
filer1.setFile(filename);
filer1.show();
directory=filer1.getDirectory();
String file=file1.getFile();
if(dirctrory=null||directory.equals("")) return;
if(file==null||file.equals(""))
file=filename;
else
{
int index=filename.lastIndexOf(".");
String extn=filename.substring(index+1);
if(!extn.equals(extn1)) file=file+"."+extn;
}
directory=directory+file;
}
else
direcory+=filename;
DownloadFile down=new DownloadFile(this,path,filename,directory);
down.start();
downFile.addElement(down); }
catch(Exception e)
{textArea1.append("文件"+filename+"下载出错！\n");}
}

}