Java with BufferedReader read utf-8 files garbled

The original code:

BufferedReader reader = new BufferedReader (new FileReader (file));

Read Utf-8 file garbled, modified as follows:

FileInputStream in = new FileInputStream (file);
BufferedReader reader = new BufferedReader (new InputStreamReader (in, "UTF-8"));

Error resolution.

The cause of the problem occurs:

The problem is that in the process of FileReader reading a file, FileReader inherits InputStreamReader, but does not implement a constructor with character set parameters in the parent class, so filereader can only be decoded by the system default character set, and then in UTF-8 -> GBK-> UTF-8, the code loses during the process, causing the result to not restore the original character. The 
reason is clear, this problem is not difficult to solve, with InputStreamReader instead of Filereader,inputstreamreader isr=new InputStreamReader (new FileInputStream (FileName), "UTF-8"), so that read the file will be directly with the UTF-8 decoding, no more coding conversion.