为什么会这样？

Question

题目是这样的:写一个简单程序，读取一个文件，每次读取一行，生成另一个文件.我是这样写的：
package han;import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;public class Test8 {
public static void main(String[] args)throws Exception {
FileOutputStream out=new FileOutputStream("E:\\1.txt");
PrintWriter writer=new PrintWriter(out);
writer.println("床前明月光");
writer.println("疑是地上霜");
writer.println("举头望明月");
writer.println("低头思故乡");
FileInputStream in=new FileInputStream("E:\\1.txt");
InputStreamReader reader=new InputStreamReader(in);
BufferedReader buffered=new BufferedReader(reader);
String br=buffered.readLine();
while(br!=null){
FileOutputStream out1=new FileOutputStream("E:\\2.txt");
PrintWriter writer1=new PrintWriter(out);
writer1.println(br);
br=buffered.readLine();
}


}}
运行了一下，发现生成1.txt,但里面没内容。2.txt没生成！我不知道错在哪？请高手指导一下！谢谢！

Answer 1

下面这个可以满足楼主的要求package beans.dg.test;import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;public class Testa { public static void main(String[] args) throws Exception {
FileOutputStream out = new FileOutputStream("E:\\1.txt");
PrintWriter writer = new PrintWriter(out);
writer.println("床前明月光");
writer.println("疑是地上霜");
writer.println("举头望明月");
writer.println("低头思故乡");

writer.flush();
FileInputStream in = new FileInputStream("E:\\1.txt");
InputStreamReader reader = new InputStreamReader(in);
BufferedReader buffered = new BufferedReader(reader);
String br = null;
int i = 1;
while ((br = buffered.readLine()) != null) {
i++;
FileOutputStream out1 = new FileOutputStream("E:\\" + i + ".txt");
PrintWriter writer1 = new PrintWriter(out1);   //这里lz写成了out writer1.println(br);
writer1.flush();    //这里需要flush一下
} }}

Answer 2

答:在writer.println("低头思故乡"); 之后加上:
writer.flush();
writer.close();将:FileOutputStream out1=new FileOutputStream("E:\\2.txt"); 
PrintWriter writer1=new PrintWriter(out1  );
移到:while(br!=null){ 之前,循环的外面.最后再加上
writer1.flush();
writer1.close();

Answer 3

因为没有关闭流（下面那些close方法） public static void main(String[] args) throws Exception {
FileOutputStream out = new FileOutputStream("E:\\1.txt");
PrintWriter writer = new PrintWriter(out);
writer.println("床前明月光");
writer.println("疑是地上霜");
writer.println("举头望明月");
writer.println("低头思故乡");
writer.close();
out.close();

FileInputStream in = new FileInputStream("E:\\1.txt");
InputStreamReader reader = new InputStreamReader(in);
BufferedReader buffered = new BufferedReader(reader);
String br = null;
FileOutputStream out1 = new FileOutputStream("E:\\2.txt");
PrintWriter writer1 = new PrintWriter(out1);
while ((br = buffered.readLine()) != null) {
writer1.println(br);
}
writer1.close();
out1.close();
buffered.close();
reader.close();
in.close();
}

Answer 4

最重要的是
writer1.flush(); 
writer1.close(); 
必须关闭流