TFTPExample.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.net.examples.ftp;
import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.time.Duration;
import org.apache.commons.net.tftp.TFTP;
import org.apache.commons.net.tftp.TFTPClient;
import org.apache.commons.net.tftp.TFTPPacket;
/**
* This is an example of a simple Java TFTP client. Notice how all the code is really just argument processing and error handling.
* <p>
* Usage: TFTPExample [options] hostname localfile remotefile hostname - The name of the remote host, with optional :port localfile - The name of the local file
* to send or the name to use for the received file remotefile - The name of the remote file to receive or the name for the remote server to use to name the
* local file being sent. options: (The default is to assume -r -b) -s Send a local file -r Receive a remote file -a Use ASCII transfer mode -b Use binary
* transfer mode.
* </p>
*/
public final class TFTPExample {
static final String USAGE = "Usage: TFTPExample [options] hostname localfile remotefile\n\n" + "hostname - The name of the remote host [:port]\n"
+ "localfile - The name of the local file to send or the name to use for\n" + "\tthe received file\n"
+ "remotefile - The name of the remote file to receive or the name for\n" + "\tthe remote server to use to name the local file being sent.\n\n"
+ "options: (The default is to assume -r -b)\n" + "\t-t timeout in seconds (default 60s)\n" + "\t-s Send a local file\n"
+ "\t-r Receive a remote file\n" + "\t-a Use ASCII transfer mode\n" + "\t-b Use binary transfer mode\n" + "\t-v Verbose (trace packets)\n";
private static boolean close(final TFTPClient tftp, final Closeable output) {
boolean closed;
tftp.close();
try {
if (output != null) {
output.close();
}
closed = true;
} catch (final IOException e) {
closed = false;
System.err.println("Error: error closing file.");
System.err.println(e.getMessage());
}
return closed;
}
public static void main(final String[] args) throws IOException {
boolean receiveFile = true, closed;
int transferMode = TFTP.BINARY_MODE, argc;
String arg;
final String hostname;
final String localFilename;
final String remoteFilename;
final TFTPClient tftp;
int timeout = 60000;
boolean verbose = false;
// Parse options
for (argc = 0; argc < args.length; argc++) {
arg = args[argc];
if (!arg.startsWith("-")) {
break;
}
if (arg.equals("-r")) {
receiveFile = true;
} else if (arg.equals("-s")) {
receiveFile = false;
} else if (arg.equals("-a")) {
transferMode = TFTP.ASCII_MODE;
} else if (arg.equals("-b")) {
transferMode = TFTP.BINARY_MODE;
} else if (arg.equals("-t")) {
timeout = 1000 * Integer.parseInt(args[++argc]);
} else if (arg.equals("-v")) {
verbose = true;
} else {
System.err.println("Error: unrecognized option.");
System.err.print(USAGE);
System.exit(1);
}
}
// Make sure there are enough arguments
if (args.length - argc != 3) {
System.err.println("Error: invalid number of arguments.");
System.err.print(USAGE);
System.exit(1);
}
// Get host and file arguments
hostname = args[argc];
localFilename = args[argc + 1];
remoteFilename = args[argc + 2];
// Create our TFTP instance to handle the file transfer.
if (verbose) {
tftp = new TFTPClient() {
@Override
protected void trace(final String direction, final TFTPPacket packet) {
System.out.println(direction + " " + packet);
}
};
} else {
tftp = new TFTPClient();
}
// We want to timeout if a response takes longer than 60 seconds
tftp.setDefaultTimeout(Duration.ofSeconds(timeout));
// We haven't closed the local file yet.
closed = false;
// If we're receiving a file, receive, otherwise send.
if (receiveFile) {
closed = receive(transferMode, hostname, localFilename, remoteFilename, tftp);
} else {
// We're sending a file
closed = send(transferMode, hostname, localFilename, remoteFilename, tftp);
}
System.out.println("Recd: " + tftp.getTotalBytesReceived() + " Sent: " + tftp.getTotalBytesSent());
if (!closed) {
System.out.println("Failed");
System.exit(1);
}
System.out.println("OK");
}
private static void open(final TFTPClient tftp) throws IOException {
try {
tftp.open();
} catch (final SocketException e) {
throw new IOException("Error: could not open local UDP socket.", e);
}
}
private static boolean receive(final int transferMode, final String hostname, final String localFilename, final String remoteFilename,
final TFTPClient tftp) throws IOException {
final File file = new File(localFilename);
// If file exists, don't overwrite it.
if (file.exists()) {
System.err.println("Error: " + localFilename + " already exists.");
return false;
}
FileOutputStream output;
// Try to open local file for writing
try {
output = new FileOutputStream(file);
} catch (final IOException e) {
tftp.close();
throw new IOException("Error: could not open local file for writing.", e);
}
open(tftp);
final boolean closed;
// Try to receive remote file via TFTP
try {
final String[] parts = hostname.split(":");
if (parts.length == 2) {
tftp.receiveFile(remoteFilename, transferMode, output, parts[0], Integer.parseInt(parts[1]));
} else {
tftp.receiveFile(remoteFilename, transferMode, output, hostname);
}
} catch (final UnknownHostException e) {
System.err.println("Error: could not resolve hostname.");
System.err.println(e.getMessage());
System.exit(1);
} catch (final IOException e) {
System.err.println("Error: I/O exception occurred while receiving file.");
System.err.println(e.getMessage());
System.exit(1);
} finally {
// Close local socket and output file
closed = close(tftp, output);
}
return closed;
}
private static boolean send(final int transferMode, final String hostname, final String localFilename, final String remoteFilename, final TFTPClient tftp)
throws IOException {
FileInputStream input;
// Try to open local file for reading
try {
input = new FileInputStream(localFilename);
} catch (final IOException e) {
tftp.close();
throw new IOException("Error: could not open local file for reading.", e);
}
open(tftp);
final boolean closed;
// Try to send local file via TFTP
try {
final String[] parts = hostname.split(":");
if (parts.length == 2) {
tftp.sendFile(remoteFilename, transferMode, input, parts[0], Integer.parseInt(parts[1]));
} else {
tftp.sendFile(remoteFilename, transferMode, input, hostname);
}
} catch (final UnknownHostException e) {
System.err.println("Error: could not resolve hostname.");
System.err.println(e.getMessage());
System.exit(1);
} catch (final IOException e) {
System.err.println("Error: I/O exception occurred while sending file.");
System.err.println(e.getMessage());
System.exit(1);
} finally {
// Close local socket and input file
closed = close(tftp, input);
}
return closed;
}
}