import java.io.*;
import java.net.*;
import java.util.*;
import java.util.logging.*;
public class Redirector {
private static final Logger logger = Logger.getLogger("Redirector");
private final int port;
private final String newSite;
public Redirector(String newSite, int port) {
this.port = port;
this.newSite = newSite;
}
public void start() {
try (ServerSocket server = new ServerSocket(port)) {
logger.info("Redirecting connections on port "
+ server.getLocalPort() + " to " + newSite);
while (true) {
try {
Socket s = server.accept();
Thread t = new RedirectThread(s);
t.start();
} catch (IOException ex) {
logger.warning("Exception accepting connection");
} catch (RuntimeException ex) {
logger.log(Level.SEVERE, "Unexpected error", ex);
}
}
} catch (BindException ex) {
logger.log(Level.SEVERE, "Could not start server.", ex);
} catch (IOException ex) {
logger.log(Level.SEVERE, "Error opening server socket", ex);
}
}
private class RedirectThread extends Thread {
private final Socket connection;
RedirectThread(Socket s) {
this.connection = s;
}
public void run() {
try {
Writer out = new BufferedWriter(
new OutputStreamWriter(
connection.getOutputStream(), "US-ASCII"
)
);
Reader in = new InputStreamReader(
new BufferedInputStream(
connection.getInputStream()
)
);
// read the first line only; that's all we need
StringBuilder request = new StringBuilder(80);
while (true) {
int c = in.read();
if (c == '\r' || c == '\n' || c == -1) break;
request.append((char) c);
}
String get = request.toString();
String[] pieces = get.split("\\w*");
String theFile = pieces[1];
// If this is HTTP/1.0 or later send a MIME header
if (get.indexOf("HTTP") != -1) {
out.write("HTTP/1.0 302 FOUND\r\n");
Date now = new Date();
out.write("Date: " + now + "\r\n");
out.write("Server: Redirector 1.1\r\n");
out.write("Location: " + newSite + theFile + "\r\n");
out.write("Content-type: text/html\r\n\r\n");
out.flush();
}
// Not all browsers support redirection so we need to
// produce HTML that says where the document has moved to.
out.write("Document moved\r\n");
out.write("Document moved
\r\n");
out.write("The document " + theFile
+ " has moved to\r\n"
+ newSite + theFile
+ ".\r\n Please update your bookmarks");
out.write("\r\n");
out.flush();
logger.log(Level.INFO,
"Redirected " + connection.getRemoteSocketAddress());
} catch(IOException ex) {
logger.log(Level.WARNING,
"Error talking to " + connection.getRemoteSocketAddress(), ex);
} finally {
try {
connection.close();
} catch (IOException ex) {}
}
}
}
public static void main(String[] args) {
int thePort;
String theSite;
try {
theSite = args[0];
// trim trailing slash
if (theSite.endsWith("/")) {
theSite = theSite.substring(0, theSite.length() - 1);
}
} catch (RuntimeException ex) {
System.out.println(
"Usage: java Redirector http://www.newsite.com/ port");
return;
}
try {
thePort = Integer.parseInt(args[1]);
} catch (RuntimeException ex) {
thePort = 80;
}
Redirector redirector = new Redirector(theSite, thePort);
redirector.start();
}
}