《JSP实用教程(第2版)/耿祥义》错误之第四章例7

书上的源代码

//ListFile.java
package tom.jiafei;
import java.io.*;
class FileName implements FilenameFilter 
{  String str=null;
   FileName (String s)
   { str="."+s;
   }
   public  boolean accept(File dir,String name)
   { return name.endsWith(str);
   }              
}
public class ListFile
{  String extendsName=null;
   StringBuffer allFileName; 
   public void setExtendsName(String s)
   { extendsName=s;
   }
   public String getExtendsName()
   { return extendsName;
   }
  public StringBuffer getFileName()
  {  File dir=new File("d:/2000");
     FileName help=new FileName(extendsName);
     String file_name[]=dir.list(help);
     for(int i=0;i<file_name.length;i++)
     {  allFileName.append(file_name[i]+" ");
     }
     return allFileName;
  }  
}//ListFile.java
package tom.jiafei;