哪为大哥帮我把这个程序编译通过

Question

F:\linhaiwen\j2ee\java>javac ReadMultiFile.java
ReadMultiFile.java:9: non-static variable this cannot be referenced from a stati
c context
        FileFilter fFilter=new FileFilter("f:\\linhaiwen\\j2ee","java");
                           ^
1 error

Answer 1

FileFilter是interface,不能直接new的

Answer 2

嵌套类放到外面来放到外面后
import java.io.*;
import java.util.*;
class ReadMutilFile 
{
public static void main(String[] args) throws Exception
{
try
{
FileFilter fFilter=new FileFilter("f:\\linhaiwen\\j2ee","java");
SequenceInputStream seqInput=new SequenceInputStream(fFilter);
FileOutputStream fOutput=new FileOutputStream("sourcesum.java");
int nContent;
while ((nContent=seqInput.read())!=-1)
{
fOutput.write(nContent);
}
seqInput.close();
fOutput.close();
}
catch(FileNotFoundException e1)
{
e1.printStackTrace();
}
// System.out.println("Hello World!");
}
}
class FileFilter implements Enumeration
{
File directory;
String extension;
String strFileList[];
Filter filter;
int nCounter;
FileFilter(String strDirectoryName,String extension)
{
this.extension=extension;
directory=new File(strDirectoryName);
if (directory.isDirectory())
{
filter=new Filter(extension);
strFileList=directory.list(filter);
}
else 
{
strFileList=new String[1];
strFileList[0]=strDirectoryName;
}
nCounter=0;
}
public boolean hasMoreElements()
{
if (nCounter<strFileList.length)
{
return true;
}
else
{
return false;
}
}
public Object nextElement()
{
// try
// {
if (hasMoreElements())
{
nCounter++;
return new FileInputStream(strFileList[nCounter-1]);
}
else 
return null;
// }
// catch(FileNotFoundException e2)
// {
// e2.printStackTrace();
// }
}
}
class Filter implements FilenameFilter
{
String extension;
Filter(String extension)
{
this.extension=extension;
}
public boolean accept(File directory,String filename)
{
return filename.endsWith("."+extension);
}
}
F:\linhaiwen\j2ee>javac ReadMultiFile.java
ReadMultiFile.java:68: unreported exception java.io.FileNotFoundException; must
be caught or declared to be thrown
                        return new FileInputStream(strFileList[nCounter-1]);
                               ^
1 error这里要怎么抛出异常，哪位可否编译通过后贴上来，我马上结贴

Answer 3

将 nextElement()方法替换成下面的，编译能通过，运行怎么样不知道
public Object nextElement()
{
// try
// {
if (hasMoreElements())
{
nCounter++;
FileInputStream fis=null;
try{
fis=new FileInputStream(strFileList[nCounter-1]);
}catch(FileNotFoundException ex){
System.out.println("找不到指定文件");
ex.printStackTrace();
}
return fis;
}
else 
return null;
// }
// catch(FileNotFoundException e2)
// {
// e2.printStackTrace();
// }
}
}