Create a nonblocking server socket channel with ServerSocketChannel - Java Network

Java examples for Network:Socket Channel

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Description

Create a nonblocking server socket channel with ServerSocketChannel

Demo Code

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.util.Iterator;
import java.util.Set;

public class Main {

  public Main() {
    try {// w  ww  . j  a v  a  2  s  . co m
      // Create a nonblocking server socket channel
      ServerSocketChannel sockChannel = ServerSocketChannel.open();
      sockChannel.configureBlocking(false);

      InetSocketAddress server = new InetSocketAddress("localhost", 79);
      ServerSocket socket = sockChannel.socket();
      socket.bind(server);

      Selector selector = Selector.open();
      sockChannel.register(selector, SelectionKey.OP_ACCEPT);

      while (true) {
        // Wait for a connection
        selector.select();

        // Get list of selection keys with pending events
        Set keys = selector.selectedKeys();
        Iterator it = keys.iterator();

        // Handle each key
        while (it.hasNext()) {

          // Get the key and remove it from the iteration
          SelectionKey selKey = (SelectionKey) it.next();

          it.remove();
          if (selKey.isAcceptable()) {

            // Create a socket connection with the client
            ServerSocketChannel selChannel = (ServerSocketChannel) selKey
                .channel();
            ServerSocket selSocket = selChannel.socket();
            Socket connection = selSocket.accept();

            // Handle the finger request
            handleRequest(connection);
            connection.close();
          }
        }
      }
    } catch (IOException ioe) {
      System.out.println(ioe.getMessage());
    }
  }

  private void handleRequest(Socket connection) throws IOException {

    // Set up input and output
    InputStreamReader isr = new InputStreamReader(connection.getInputStream());
    BufferedReader is = new BufferedReader(isr);
    PrintWriter pw = new PrintWriter(new BufferedOutputStream(
        connection.getOutputStream()), false);

    // Output server greeting
    pw.println("Nio Finger Server");
    pw.flush();

    // Handle user input
    String outLine = null;
    String inLine = is.readLine();

    if (inLine.length() > 0) {
      outLine = inLine;
    }
    readPlan(outLine, pw);

    // Clean up
    pw.flush();
    pw.close();
    is.close();
  }

  private void readPlan(String userName, PrintWriter pw) {
    try {
      FileReader file = new FileReader(userName + ".plan");
      BufferedReader buff = new BufferedReader(file);
      boolean eof = false;

      pw.println("\nUser name: " + userName + "\n");

      while (!eof) {
        String line = buff.readLine();

        if (line == null) {
          eof = true;
        } else {
          pw.println(line);
        }
      }

      buff.close();
    } catch (IOException e) {
      pw.println("User " + userName + " not found.");
    }
  }

  public static void main(String[] arguments) {
    Main nio = new Main();
  }
}

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