如何生成.txt文件为UTF-8编码？

Question

I want to write a code to convert UTF-8 encoded in java.I creating "a.txt" file which contains only English characters inside the "a.txt" file.While generating, It's giving me ANSI encoded version but I need UTF-8 encoded version.

Note:- A file does not contain any special characters, it contains only ASCI value.

I have written below code.

writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), "UTF-8")); 
writer.write(content);

Answer 1

There is no such thing as ANSI encoding (it is an imprecise term for single byte character sets whose first 128 characters are ASCII); and if your file only contains ASCII (characters 0 - 127), then it doesn't matter if you use UTF-8 or one of the 'ANSI' encodings.

Considering that editors infer character sets (or better: guess(!)), and that UTF-8 with only ASCII 0 - 127 is indistinguishable from actual ASCII, or one of the 'ANSI' encodings, this is entirely expected

This means that if you write a file with - for example - only "ABC" in UTF-8, it is also valid ASCII, Windows-1252, ISO-8859-x, and any other character set that takes ASCII as its starting point. The editor cannot decide what the actual character set is, and just reports ANSI.

In other words: your code is working ok; it is just the heuristics of your editor that is guessing the wrong character set. In the end, text files are just a stream of bytes that only get meaning when applying the right character set; the character set is not specified in the file itself.

PS: The code in your question has a typo in that it reference UTF-18 , which does not exist.