如何让 PrintWriter 写成 UTF-8？

Question

How to make the PrintWriter to write UTF-8?

pstream = new PrintWriter(csocket.getOutputStream(), true);
String res = "some string";
pstream.println(res); // here I want to output string as UTF-8

Answer 1

Use an OutputStreamWriter :

pstream = new PrintWriter(new OutputStreamWriter(
    csocket.getOutputStream(), StandardCharsets.UTF_8), true)

Answer 2

OutputStream os = new FileOutputStream("file.txt");
PrintWriter pw = new PrintWriter(new OutputStreamWriter(os, "UTF-8"));

Answer 3

Look at Java: Difference between PrintStream and PrintWriter discussion.

To be quick: you can use -Dfile.encoding=utf8 JVM parameter or method suggested in the discussion (see second answer).

Answer 4

PrintWriter out1 = null;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
    out1 = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), StandardCharsets.UTF_8),true);
} else { 
    out1 = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), "UTF8"), true);
}

Answer 5

Don't user PrintWriter. If you need UTF-8 encoding, just write direct to the OutputStream.

csocket.getOutputStream().write(res.getBytes("UTF-8"));

Answer 6

您只能使用任何字符集写入文件，否则使用平台默认字符集，请参阅文档