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javafileioprintwriterwriter

Java PrintWriter File Overwrite

I want to write into a file using UTF-16 so I use PrintWriter(file,"UTF-16"), but then it deletes everything in the file, I could use FileWriter(file,true), but then it wouldn't be in UTF-16, and there apparently isn't a constructor for PrintWriter like PrintWriter(Writer,Charset,boolean append);

What should I do?

Solution

  • The JavaDoc for FileWriter says:

    The constructors of this class assume that the default character encoding and the default byte-buffer size are acceptable. To specify these values yourself, construct an OutputStreamWriter on a FileOutputStream.

    So you can do:

     Writer writer = new PrintWriter(
     new OutputStreamWriter(
           new FileOutputStream(filename, true),
           StandardCharsets.UTF16));

    You might want to include BufferedOutputStream in there too for maximum efficiency.