写入从getResourceAsStream（）返回的文件流

Question

I am getting aa InputStream from getResourceAsStream() , and I managed to read from the file by passing the returned InputStream to a BufferedReader .

Is there any way I can write to the file as well?

Answer 1

Not directly, no - getResourceAsStream() is intended to return a view on read-only resources.

If you know that the resource is a writeable file, though, you can jump through some hoops, eg

URL resourceUrl = getClass().getResource(path);
File file = new File(resourceUrl.toURI());
OutputStream output = new FileOutputStream(file);

This should work nicely on unix-style systems, but windows file paths might give this indigestion. Try it and find out, though, you might be OK.

Answer 2

Is there any way I can write to the file as well?

Who says it's a file? The whole point of getResourceAsStream() is to abstract that away because it might well not be true. Specifically, the resource may be situated in a JAR file, may be read from a HTTP server, or really anything that the implementer of the ClassLoader could imagine.

You really shouldn't want to write to a resource that's part of your program distribution. It's conceptually the wrong thing to do in most cases. Settings or User-specific data should go to the Preferences API or the user's home directory.