java 讀取txt文件亂碼

private void msgTxt(){

try {
InputStreamReader isr = new InputStreamReader(new FileInputStream("文件路徑"), "UTF-8");   //設置爲UTF-8
BufferedReader br = new BufferedReader(isr);
String s1 = null;
while((s1 = br.readLine()) != null) {
       System.out.println(s1.toString());
} 
br.close();
isr.close(); 
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
 
  }