JAVA中的SSL套接字连接池

Question

I am creating a SSL server-client. Till now, what I have implemented is a simple server which can talk to a single client (no threading, that is). Now, I want to scale this application for multiple clients and I want to use connection pooling for that. Now, do I need to use threading for that or is there inbuilt library that I can use. Any examples, link etc would work.

PS: I have tried googling but have not found a suitable link.

Below is my code if required:

Server:

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.UnrecoverableKeyException;
import java.security.cert.CertificateException;

import javax.net.ssl.*;

public class SSLServer {

    public static void main(String args[]){
        String ksname = "file.jks";
        char kspass[] = "pass".toCharArray();
        char ctpass[] = "pass".toCharArray();

        try {
            KeyStore ks = KeyStore.getInstance("JKS");
            ks.load(new FileInputStream(ksname), kspass);
            KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
            kmf.init(ks, ctpass);
            SSLContext sc = SSLContext.getInstance("TLS");
            sc.init(kmf.getKeyManagers(), null, null);
            SSLServerSocketFactory ssf = sc.getServerSocketFactory();
            SSLServerSocket s = (SSLServerSocket) ssf.createServerSocket(4321);
            //printServerSocketInfo(s);
            SSLSocket c = (SSLSocket) s.accept();
            //printSocketInfo(c);

            BufferedReader r = new BufferedReader(new InputStreamReader(c.getInputStream()));
            BufferedWriter w = new BufferedWriter(new OutputStreamWriter(c.getOutputStream()));

            w.write("Server starts\n");

            w.flush();
            String k = null;
            while((k = r.readLine()) != null){
                //do something
                if(k.equals("end"))
                    break;
                w.write(resolve(k));
                w.newLine();
                w.flush();
            }
            w.close();
            r.close();
            c.close();
            s.close();

        } catch (KeyStoreException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (NoSuchAlgorithmException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (CertificateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (UnrecoverableKeyException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (KeyManagementException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }   
    }

    private static void printSocketInfo(SSLSocket s) {
          System.out.println("Socket class: "+s.getClass());
          System.out.println("   Remote address = "
             +s.getInetAddress().toString());
          System.out.println("   Remote port = "+s.getPort());
          System.out.println("   Local socket address = "
             +s.getLocalSocketAddress().toString());
          System.out.println("   Local address = "
             +s.getLocalAddress().toString());
          System.out.println("   Local port = "+s.getLocalPort());
          System.out.println("   Need client authentication = "
             +s.getNeedClientAuth());
          SSLSession ss = s.getSession();
          System.out.println("   Cipher suite = "+ss.getCipherSuite());
          System.out.println("   Protocol = "+ss.getProtocol());
    }

    private static void printServerSocketInfo(SSLServerSocket s) {
          System.out.println("Server socket class: "+s.getClass());
          System.out.println("   Socket address = "
             +s.getInetAddress().toString());
          System.out.println("   Socket port = "
             +s.getLocalPort());
          System.out.println("   Need client authentication = "
             +s.getNeedClientAuth());
          System.out.println("   Want client authentication = "
             +s.getWantClientAuth());
          System.out.println("   Use client mode = "
             +s.getUseClientMode());
    }

    private static String resolve(String p){
        //some implementation
        return "something";
    }

    }

Client:

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.UnknownHostException;

import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;

public class SSLClient {

    public static void main(String[] args){

        SSLSocketFactory f = (SSLSocketFactory) SSLSocketFactory.getDefault();

        try {
            SSLSocket c = (SSLSocket) f.createSocket("localhost", 4321);
            printSocketInfo(c);
            c.startHandshake();
            BufferedWriter w = new BufferedWriter(new OutputStreamWriter(c.getOutputStream()));
            BufferedReader r = new BufferedReader(new InputStreamReader(c.getInputStream()));

            //to input hex code message
            BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
            String k = null;
            while((k = r.readLine()) != null){
                //send message to server
                System.out.println(k);
                System.out.flush();
                k = in.readLine();
                if(k.equals("."))
                    break;
                System.out.println(k);
                System.out.flush();
                w.write(k);
                w.newLine();
                w.flush();
            }
            w.close();
            r.close();
            c.close();
        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

Answer 1

Your server is able to connect to multiple clients. In your code you've initialized a SSLServerSocket who's task it is to wait for additional clients - each of them will get it's own SSLSocket .

If your server isn't able to handle all clients, you'd use something like a loadbalancer which spreads the incoming requests to different server.

Connection Pooling is typically used inside a server - eg for talking to a database.

Does this answer your question? If not, is your intention to spread the requests to more than one server or to get to know what connection pooling is for?

Answer 2

Connection pooling is implenented at the client.

At the server end, all you can do is accept connections and not terminate them until closed by the client, or until some read timeout occurs trying to read the second or subsequent request.