海贼王罗pk明哥:请教高手

我想请问一下我要执行命令行操作应该怎么实现啊!
public class Stream
{
public static void main(String[] args)
{
FileInputStream fis1=null;
FileInputStream fis2=null;
FileOutputStream fos=null;
if(args.length!=3)
{
System.out.println("java file error!");
System.exit(0);
}
try
{
fis1=new FileInputStream(new File(args[0]));
fis2=new FileInputStream(new File(args[1]));
File file=new File(args[2]);
if(file.exists())
{
System.out.println("The file"+args[2]+"already exists");
return;
}
else fos=new FileOutputStream(args[2]);
System.out.println("The file"+args[0]+"has"+fis1.available()+"bytes");
System.out.println("The file"+args[1]+"has"+fis2.available()+"byte");
int r;
while(fis1.read()!=-1&&fis2.read()!=-1)
{
r=fis1.read();
fos.write((byte)r);
r=fis2.read();
fos.write((byte)r);
}
while((r=fis1.read())!=-1)
{
fos.write((byte)r);
}
while((r=fis2.read())!=-1)
{
fos.write((byte)r);
}
}
catch(FileNotFoundException ex)
{
System.out.println("File not found:"+args[0]+"or"+args[1]);
}
catch(IOException ex)
{
System.out.println(ex.getMessage());
}
finally
{
try
{
if(fis1!=null) fis1.close();
if(fis2!=null) fis2.close();
if(fos!=null) fos.close();
}
catch(IOException ex)
{
System.out.println(ex);
}
}
}
}