String pathname = "web/static/outPutFile.txt"; 
FileReader reader = new FileReader(pathname);
BufferedReader br = new BufferedReader(reader);

原因：编码和解码的方式不一致导致乱码

解决方法一：将txt文件的编码方式设置为UTF-8.

解决方法二：使用转换流InputStreamReader，并设置解码方式为GBK

String pathname = "web/static/outPutFile.txt";
FileInputStream fis= new FileInputStream(new File(pathname));
InputStreamReader isr=new InputStreamReader(fis,"GBK");
BufferedReader br = new BufferedReader(isr);