Develop Reference

Trying to run a simple example of Java NIO SSL to load the contents of https://www.amazon.com but getting 400 Bad Request

Trying everyting but it does not work :(
The complete code and example can be found here: https://examples.javacodegeeks.com/core-java/nio/java-nio-ssl-example/
Also you can download the full source (it is only 3 classes) by clicking here: https://examples.javacodegeeks.com/wp-content/uploads/2015/12/NioSSLExample.zip
Thanks for any help!
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLEngine;
import javax.net.ssl.SSLSession;
public class NioSSLExample
{
public static void main(String[] args) throws Exception
{
InetSocketAddress address = new InetSocketAddress("www.amazon.com", 443);
Selector selector = Selector.open();
SocketChannel channel = SocketChannel.open();
channel.connect(address);
channel.configureBlocking(false);
int ops = SelectionKey.OP_CONNECT | SelectionKey.OP_READ;
SelectionKey key = channel.register(selector, ops);
// create the worker threads
final Executor ioWorker = Executors.newSingleThreadExecutor();
final Executor taskWorkers = Executors.newFixedThreadPool(2);
// create the SSLEngine
final SSLEngine engine = SSLContext.getDefault().createSSLEngine();
engine.setUseClientMode(true);
engine.beginHandshake();
final int ioBufferSize = 32 * 1024;
final NioSSLProvider ssl = new NioSSLProvider(key, engine, ioBufferSize, ioWorker, taskWorkers)
{
#Override
public void onFailure(Exception ex)
{
System.out.println("handshake failure");
ex.printStackTrace();
}
#Override
public void onSuccess()
{
System.out.println("handshake success");
SSLSession session = engine.getSession();
try
{
System.out.println("local principal: " + session.getLocalPrincipal());
System.out.println("remote principal: " + session.getPeerPrincipal());
System.out.println("cipher: " + session.getCipherSuite());
}
catch (Exception exc)
{
exc.printStackTrace();
}
//HTTP request
StringBuilder http = new StringBuilder();
http.append("GET / HTTP/1.0\r\n");
http.append("Connection: close\r\n");
http.append("\r\n");
byte[] data = http.toString().getBytes();
ByteBuffer send = ByteBuffer.wrap(data);
this.sendAsync(send);
}
#Override
public void onInput(ByteBuffer decrypted)
{
// HTTP response
byte[] dst = new byte[decrypted.remaining()];
decrypted.get(dst);
String response = new String(dst);
System.out.print(response);
System.out.flush();
}
#Override
public void onClosed()
{
System.out.println("ssl session closed");
}
};
// NIO selector
while (true)
{
key.selector().select();
Iterator keys = key.selector().selectedKeys().iterator();
while (keys.hasNext())
{
keys.next();
keys.remove();
ssl.processInput();
}
}
}
}

http.append("GET / HTTP/1.0\r\n");
http.append("Connection: close\r\n");
http.append("\r\n");
While this is in theory a correct HTTP/1.0 request in practice, most systems today require that a Host header is included. While this is mandatory only with HTTP/1.1 it is needed if an IP address hosts multiple domains:
http.append("GET / HTTP/1.0\r\n");
http.append("Host: www.amazon.com\r\n");
http.append("\r\n");
Also note that the Connection: close is unnecessary since it is implicit with HTTP/1.0 (but not with HTTP/1.1).
Apart from that HTTP is way more complex than this simple request and even this one had its problems as you saw. If you need to implement it for yourself please study the standards instead of making assumptions of how servers react or looking only at a few examples.

Running a live Java Server on Amazon AWS

I am developing a Client-Server application with several other programmers, in Java. At this point in time I do not want to be running the code locally. I want to be able to connect to the Server from any machine.
I wrote a test server and test client, just to make sure that things are working properly. But they are not. I am using Amazon AWS EC2 Linux that comes with Java. I am able to compile and run my Server after I SSH into the EC2, but the Client on my local disk is just not connecting. Here is the code.
// Code found online (https://cs.lmu.edu/~ray/notes/javanetexamples/)
import java.io.IOException;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
import java.util.concurrent.Executors;
import java.util.concurrent.ExecutorService;
public class TestServer {
public static void main(String[] args) throws Exception {
try (ServerSocket listener = new ServerSocket(50000)) {
System.out.println("The capitalization server is running...");
System.out.println(listener.getInetAddress());
ExecutorService pool = Executors.newFixedThreadPool(20);
while (true) {
pool.execute(new Capitalizer(listener.accept()));
}
}
}
private static class Capitalizer implements Runnable {
private Socket socket;
Capitalizer(Socket socket) {
this.socket = socket;
}
#Override
public void run() {
System.out.println("Connected: " + socket);
try {
Scanner in = new Scanner(socket.getInputStream());
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
while (in.hasNextLine()) {
out.println(in.nextLine().toUpperCase());
}
} catch (Exception e) {
System.out.println("Error:" + socket);
} finally {
try { socket.close(); } catch (IOException e) {}
System.out.println("Closed: " + socket);
}
}
}
}
// Code found online (https://cs.lmu.edu/~ray/notes/javanetexamples/)
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Scanner;
public class TestClient {
public static void main(String[] args) throws Exception {
try (Socket socket = new Socket("ADDRESS HERE", 50000)) {
System.out.println("Enter lines of text then Ctrl+D or Ctrl+C to quit");
Scanner scanner = new Scanner(System.in);
Scanner in = new Scanner(socket.getInputStream());
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
while (scanner.hasNextLine()) {
out.println(scanner.nextLine());
System.out.println(in.nextLine());
}
}
}
}
In place of "ADDRESS HERE" in the Client, I have tried the private IP and public IP of my Amazon EC2 instance. I have also tried the public DNS name. Nothing seems to work. There is just no connection from the Client to the Server. In fact, "Enter lines of text then Ctrl+D or Ctrl+C to quit" never prints.
All help is appreciated. Thank you.

Allow your IP address to send request to the EC2. For this, you need to go to your Security Group and add your IP there. Follow these steps-
GO to your AWS console.
Click on EC2, then under Resources you will find Security Groups.
Select your security group.
Follow the steps in the given image.

Since you're able to connect to EC2 instance via SSH, your Security Group allows this.
Now you need to allow requests from the client in this Security Group. You will either need to provide a concrete IP, IP range or allow all IPs (not recommended) in the group.
You can find how to do this here.

Java XML RPC getting Time Out Exception

Need help to get response from server using java library helma.xmlrpc, i have read and try code in this link : XML-RPC to connect confluence in JAVA, this is the code that i've tried :
import java.util.Vector;
import java.util.Hashtable;
import helma.xmlrpc.*;
import java.util.Arrays;
public class RPC_appache {
// The location of our server.
private final static String server_url ="http://11.111.22.213:6789";
public static void main (String [] args) {
try {
// Create an object to represent our server.
XmlRpcClient server = new XmlRpcClient(server_url);
Vector<Object> params = new Vector<Object>();
params.add("username");
params.add("pass");
params.add("username");
params.add("pass");
String token = (String) server.execute("topUpInquiry", params );
System.out.println(token);
}
catch (Exception exception) {
exception.printStackTrace();
System.err.println("JavaClient: " + exception.toString());
}
}
}
but I am getting this error :
java.io.IOException: Connection timed out: connect at
helma.xmlrpc.XmlRpcClient$Worker.execute(XmlRpcClient.java:135) at
helma.xmlrpc.XmlRpcClient.execute(XmlRpcClient.java:67) at
id.my.berkah.dmt.H2HRPC.RPC_appache.main(RPC_appache.java:31)
JavaClient: java.io.IOException: Connection timed out: connect

Android Phone as Realtime MJPEG Video Server

I'm trying to use my phone as a realtime MJPEG video source. So far, capturing frames and converting them into JPEGs is no big deal. My real issue is sending the multipart response properly. There's tons of documentation about sending multipart responses out there, but the issue with them is that they all expect that all of the images are available at the time the HTTP request comes in (such as would be used for a multi-image upload). In order to stream in realtime, of course, I need to be able to begin to send the multipart response while continually adding jpegs in the body. I'm by no means a HTTP buff, so it's not desirable for me be required to roll my own HTTP response and write directly to a socket. Is there a library out there that supports this kind of behavior? I've scoured the internet for solutions, but I really don't see anything useful out there.
Any ideas? Worst case scenario, I'd be willing to look at human-readable documentation of how to write a multipart response by hand, but I'd really just rather use a library if that's possible.
Thanks in advance.
edit: got it working using the orielly servlet library as per sigmavirus' suggestion. Note that the MJPEG stream is more or less implicitly inferred from the fact that I'm sending a multipart/x-mixed-replace that only has image/jpeg's in it. Check out the comment in my code for a tutorial that shows what jetty libraries you'll need to get this running. Of course, you'll additionally need cos.jar, the Orielly servlet library. The code follows:
package edu.stevens.arpac.webclient;
import java.io.IOException;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.util.Collections;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletRequest;
import org.apache.http.conn.util.InetAddressUtils;
import org.eclipse.jetty.server.Handler;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.handler.AbstractHandler;
import org.eclipse.jetty.server.Request;
import com.oreilly.servlet.MultipartResponse;
import com.oreilly.servlet.ServletUtils;
import android.os.Environment;
import android.util.Log;
// holla at http://puregeekjoy.blogspot.com/2011/06/running-embedded-jetty-in-android-app.html
public class JettyServer extends Thread
{
private static final String TAG = "JettyServer";
private Server webServer;
private Boolean isStarted = false;
public JettyServer()
{
super();
Log.i(TAG, "Initializing server to port 8080");
webServer = new Server(8080);
Handler handler = new AbstractHandler() {
public void handle(String target, Request request, HttpServletRequest servletRequest,
HttpServletResponse servletResponse) throws IOException, ServletException {
ServletOutputStream out = servletResponse.getOutputStream();
MultipartResponse multi = new MultipartResponse(servletResponse);
Boolean go = true;
while( go )
{
try
{
multi.startResponse("image/jpeg");
ServletUtils.returnFile(Environment.getExternalStorageDirectory().getPath() + "/ARPac/twi.jpg", out);
multi.endResponse();
}
catch(IOException ex)
{
go = false;
Log.i(TAG, "IO Failed with exception " + ex.getMessage());
}
}
request.setHandled(true);
}
};
webServer.setHandler(handler);
try {
webServer.start();
Log.d(TAG, "started Web server # " + getIPAddress());
isStarted = true;
}
catch (Exception e) {
Log.d(TAG, "unexpected exception starting Web server: " + e);
}
}
/**
* Get IP address from first non-localhost interface
* #return address or empty string
*/
private String getIPAddress()
{
try
{
List<NetworkInterface> interfaces = Collections.list(NetworkInterface.getNetworkInterfaces());
for (NetworkInterface intf : interfaces)
{
List<InetAddress> addrs = Collections.list(intf.getInetAddresses());
for (InetAddress addr : addrs)
{
if (!addr.isLoopbackAddress())
{
String sAddr = addr.getHostAddress().toUpperCase();
if (InetAddressUtils.isIPv4Address(sAddr))
{
//Log.d(TAG, "IP address is: " + sAddr);
return sAddr;
}
}
}
}
}
catch (Exception ex)
{
Log.e(TAG, "could not get IP address: " + ex.getMessage());
} // for now eat exceptions
Log.e(TAG, "Could not find a non-loopback IPv4 address!");
return "";
}
public void teardown()
{
if( isStarted )
{
try {
webServer.stop();
isStarted = false;
} catch (Exception e) {
Log.e(TAG, "Couldn't stop server. Probably was called when server already stopped.");
}
}
}
public void run()
{
}
}

Have you seen this? http://www.servlets.com/cos/javadoc/com/oreilly/servlet/MultipartResponse.html It looks like the example sends each part individually and waits a specified time limit before sending the next or receiving an interrupt.

java. Skype - send message

I'm trying to understand how to work with Skype using java (JSkype lib)
i use example (official site):
package testproj;
import net.lamot.java.jskype.general.AbstractMessenger;
import net.lamot.java.jskype.general.MessageListenerInterface;
import net.lamot.java.jskype.windows.Messenger;
import java.lang.Thread;
import java.lang.Exception;
import java.util.Date;
public class JSkype implements MessageListenerInterface {
private AbstractMessenger msgr = null;
public JSkype() {
msgr = new Messenger();
msgr.addListener(this);
msgr.initialize();
try {
Thread.sleep(5000);
msgr.sendMessage("MESSAGE echo123 test message");
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
new JSkype();
}
public void onMessageReceived(String str) {
System.out.println("RESULT: "+str);
}
}
after run, in console i have many information, but for me more intresting information, that I receive after send message:
RESULT: MESSAGE 21129 STATUS SENDING
RESULT: MESSAGE 21129 STATUS SENDING
RESULT: CHAT #my.name/$echo123;9797238991f90d78 ACTIVITY_TIMESTAMP 1294574640
and now I'm trying to understand, how to determine the success of sending a message?
yep, we need parsind result string.. but what is a number 21129? 9797238991f90d78? how i can know this number before start parsing?