解决eclipse中java项目导出成jar包后读写UTF-8文件中文乱码问题

最近遇到了一个小麻烦，就是在eclipse环境中读写UTF-8格式的txt文件时很正常，但是当导出成jar包后，通过点击来读写文件时出现了部分中文乱码问题。

解决办法：
开始时用的是FileReader和FileWriter来读写的，后来改成用InputStreamReader和OutputStreamWriter后问题解决

关键代码：

BufferedReader reader;
BufferedWriter writer;

//reader = new BufferedReader(new FileReader(new File(filedir,filename)));
reader = new BufferedReader(new InputStreamReader(new FileInputStream(new File(filedir,filename)),"UTF-8"));

//writer = new BufferedWriter(new FileWriter(new File(filedir,emailDomain+".txt"),true));
writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(filedir,emailDomain+".txt"),true),"UTF-8"));

（PS：不用管代码中的具体文件路径和文件名，看懂思路即可）