hello.txt文件中没有写入内容

package it.immoc.com;

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

public class WeatherTest {

public void transWriteByBuf(){

try {

FileOutputStream fos = new FileOutputStream("hello.txt");

OutputStreamWriter osw=new OutputStreamWriter(fos);

BufferedWriter bw=new BufferedWriter(osw);

bw.write("你好吗?\r\n");

bw.write("我很好！\r\n");

bw.flush();

fos.close();

osw.close();

bw.close();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

public void transReadByBuf(){

try {

FileInputStream fis = new FileInputStream("hello.txt");

InputStreamReader isr=new InputStreamReader(fis);

BufferedReader br=new BufferedReader(isr);

String n;

while((n=br.readLine())!=null){

System.out.println(n);

}

fis.close();

isr.close();

br.close();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

public static void main(String[] args) {

// Weather wt=new Weather();

// new Thread(new GenerateWeather(wt)).start();

// new Thread(new ReadWeather(wt)).start();

WeatherTest wt=new WeatherTest();

wt.transWriteByBuf();

wt.transReadByBuf();

}

}

问题：

1. hello.txt文件中没有写入内容，

   2.直接在hello.txt文件中添加其他内容，显示在控制台上的还是bw.write()写入的内容没有其他内容,

   3.先调用读的函数后调用写的函数控制台还是能够看到bw.write()中写入的内容