byte[] to file in Java

Without any libraries:

try (FileOutputStream stream = new FileOutputStream(path)) {
    stream.write(bytes);
}

With Google Guava:

Files.write(bytes, new File(path));

With Apache Commons:

FileUtils.writeByteArrayToFile(new File(path), bytes);

All of these strategies require that you catch an IOException at some point too.

Use Apache Commons IO

FileUtils.writeByteArrayToFile(new File("pathname"), myByteArray)

Or, if you insist on making work for yourself...

try (FileOutputStream fos = new FileOutputStream("pathname")) {
   fos.write(myByteArray);
   //fos.close(); There is no more need for this line since you had created the instance of "fos" inside the try. And this will automatically close the OutputStream
}

Also since Java 7, one line with java.nio.file.Files:

Files.write(new File(filePath).toPath(), data);

Where data is your byte[] and filePath is a String. You can also add multiple file open options with the StandardOpenOptions class. Add throws or surround with try/catch.

Another solution using java.nio.file:

byte[] bytes = ...;
Path path = Paths.get("C:\\myfile.pdf");
Files.write(path, bytes);