How to read/write a file in UTF-8 in Java?

I am getting this error:

io.MalformedByteSequenceException: Invalid byte 2 of 2-byte UTF-8 sequence

The solution is to read and write a file in UTF-8.

My code is:

InputStream input = null;
OutputStream output = null;
OutputStreamWriter bufferedWriter = new OutputStreamWriter( output, "UTF8");
input = new URL(url).openStream();
output = new FileOutputStream("DirectionResponse.xml");
byte[] buffer = new byte[1024];
for (int length = 0; (length = input.read(buffer)) > 0;) {
   output.write(buffer, 0, length);
}
BufferedReader br = new BufferedReader(new FileReader("DirectionResponse.xml" ));
FileWriter fstream = new FileWriter("ppre_DirectionResponse.xml");
BufferedWriter out = new BufferedWriter(fstream);

I'm reading a url and writing it to a file DirectionResponse.xml. Then reading DirectionResponse.xml and writing the same as ppre_DirecionResponse.xml for processing.

How do I change this so that reading and writing is done in UTF-8?

Solution

First, you need to call output.close() (or at least call output.flush()) before you reopen the file for input. That's probably the main cause of your problems.

Then, you shouldn't use FileReader or FileWriter for this because it always uses the platform-default encoding (which is often not UTF-8). From the docs for FileReader:

The constructors of this class assume that the default character encoding and the default byte-buffer size are appropriate.

You have the same problem when using a FileWriter. Replace this:

BufferedReader br = new BufferedReader(new FileReader("DirectionResponse.xml" ));

with something like this:

BufferedReader br = new BufferedReader(new InputStreamReader(
    new FileInputStream("DirectionResponse.xml"), "UTF-8"));

and similarly for fstream.