新手，帮忙看看这问题

[liubinjun]

A.txt里的内容只有前面一部分导到B.txt里去，应该怎么改？

package study_java;
import java.io.*;
public class FileRead {
public static void main(String[] args) {
try{
int num=1048576;
FileInputStream filein = new FileInputStream("C:\\Documents and Settings\\Administrator\\桌面\\A.txt");
BufferedReader filein1=new BufferedReader(new InputStreamReader(filein));
String str=filein1.readLine();

FileOutputStream fileout = new FileOutputStream("C:\\Documents and Settings\\Administrator\\桌面\\B.txt", true);
BufferedWriter fileout1=new BufferedWriter(new OutputStreamWriter(fileout),num);
while (str!=null){
System.out.println(str);
fileout1.write(str);
fileout1.newLine();
str=filein1.readLine();
}
filein1.close();
}
catch(Exception e){
String err=e.toString();
System.out.println(err);
}
}
}

[liubinjun]

没人吗？是不是都不屑一顾？

[lubber]

"A.txt里的内容只有前面一部分"?条件是什么,不符合条件就不导到B里不就行了吗