private String saveTmpFile(byte[] b, int offset, int len) {
			String path = "";
			if (len > 0) {
				String tmpdir = System.getProperty("java.io.tmpdir");
				try {
					File temp = File.createTempFile("NanoHTTPD", "", new File(
							tmpdir));
					OutputStream fstream = new FileOutputStream(temp);
					fstream.write(b, offset, len);
					fstream.close();
					path = temp.getAbsolutePath();
				} catch (Exception e) { // Catch exception if any
					myErr.println("Error: " + e.getMessage());
				}
			}
			return path;
		}
Retrieves the content of a sent file and saves it to a temporary
file. The full path to the saved file is returned.
selendroid-standalone/src/test/java/io/selendroid/standalone/server/support/NanoHTTPD.java