package test;
 
import java.io.File;
import java.io.FileInputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
 
public class Test {
 public static void main(String[] args) throws Exception {
  FileInputStream fin = new FileInputStream(new File(
    "d:\\temp_buffer.tmp"));
  FileChannel fc = fin.getChannel();
  ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
  fc.read(byteBuffer);
  fc.close();
  byteBuffer.flip();//读写转换
 }
}

public static void nioCopyFile(String resource, String destination)
   throws IOException {
  FileInputStream fis = new FileInputStream(resource);
  FileOutputStream fos = new FileOutputStream(destination);
  FileChannel readChannel = fis.getChannel(); // 读文件通道
  FileChannel writeChannel = fos.getChannel(); // 写文件通道
  ByteBuffer buffer = ByteBuffer.allocate(1024); // 读入数据缓存
  while (true) {
   buffer.clear();
   int len = readChannel.read(buffer); // 读入数据
   if (len == -1) {
    break; // 读取完毕
   }
   buffer.flip();
   writeChannel.write(buffer); // 写入文件
  }
  readChannel.close();
  writeChannel.close();
 }

public static void main(String[] args) throws Exception {
  ByteBuffer b = ByteBuffer.allocate(15); // 15个字节大小的缓冲区
  System.out.println("limit=" + b.limit() + " capacity=" + b.capacity()
    + " position=" + b.position());
  for (int i = 0; i < 10; i++) {
   // 存入10个字节数据
   b.put((byte) i);
  }
  System.out.println("limit=" + b.limit() + " capacity=" + b.capacity()
    + " position=" + b.position());
  b.flip(); // 重置position
  System.out.println("limit=" + b.limit() + " capacity=" + b.capacity()
    + " position=" + b.position());
  for (int i = 0; i < 5; i++) {
   System.out.print(b.get());
  }
  System.out.println();
  System.out.println("limit=" + b.limit() + " capacity=" + b.capacity()
    + " position=" + b.position());
  b.flip();
  System.out.println("limit=" + b.limit() + " capacity=" + b.capacity()
    + " position=" + b.position());
 
 }

public static void main(String[] args) throws Exception {
  RandomAccessFile raf = new RandomAccessFile("C:\\mapfile.txt", "rw");
  FileChannel fc = raf.getChannel();
  // 将文件映射到内存中
  MappedByteBuffer mbb = fc.map(FileChannel.MapMode.READ_WRITE, 0,
    raf.length());
  while (mbb.hasRemaining()) {
   System.out.print((char) mbb.get());
  }
  mbb.put(0, (byte) 98); // 修改文件
  raf.close();
 }

public static void main(String[] args) throws Exception {
  ServerSocket echoServer = null;
  Socket clientSocket = null;
  try {
   echoServer = new ServerSocket(8000);
  } catch (IOException e) {
   System.out.println(e);
  }
  while (true) {
   try {
    clientSocket = echoServer.accept();
    System.out.println(clientSocket.getRemoteSocketAddress()
      + " connect!");
    tp.execute(new HandleMsg(clientSocket));
   } catch (IOException e) {
    System.out.println(e);
   }
  }
 }

static class HandleMsg implements Runnable{ 
   省略部分信息     
   public void run(){   
    try {   
     is = new BufferedReader(new InputStreamReader(clientSocket.getInputStream())); 
     os = new PrintWriter(clientSocket.getOutputStream(), true); 
     // 从InputStream当中读取客户端所发送的数据    
     String inputLine = null;     
     long b=System. currentTimeMillis ();     
     while ((inputLine = is.readLine()) != null)
     {   
      os.println(inputLine);     
     }     
     long e=System. currentTimeMillis ();     
     System. out.println ("spend:"+(e - b)+" ms ");    
   } catch (IOException e) {     
    e.printStackTrace();    
   }finally
   { 
    关闭资源 
   }  
  } 
  }

public static void main(String[] args) throws Exception {
  Socket client = null;
  PrintWriter writer = null;
  BufferedReader reader = null;
  try {
   client = new Socket();
   client.connect(new InetSocketAddress("localhost", 8000));
   writer = new PrintWriter(client.getOutputStream(), true);
   writer.println("Hello!");
   writer.flush();
   reader = new BufferedReader(new InputStreamReader(
     client.getInputStream()));
   System.out.println("from server: " + reader.readLine());
  } catch (Exception e) {
  } finally {
   // 省略资源关闭
  }
 }

private static ExecutorService tp= Executors.newCachedThreadPool(); 
  private static final int sleep_time=1000*1000*1000; 
  public static class EchoClient implements Runnable{ 
   public void run(){   
    try {    
     client = new Socket();    
     client.connect(new InetSocketAddress("localhost", 8000)); 
     writer = new PrintWriter(client.getOutputStream(), true); 
     writer.print("H");    
     LockSupport.parkNanos(sleep_time);  
     writer.print("e");   
     LockSupport.parkNanos(sleep_time);  
     writer.print("l");  
     LockSupport.parkNanos(sleep_time); 
     writer.print("l");  
     LockSupport.parkNanos(sleep_time); 
     writer.print("o");  
     LockSupport.parkNanos(sleep_time); 
     writer.print("!");   
     LockSupport.parkNanos(sleep_time); 
     writer.println();  
     writer.flush(); 
    }catch(Exception e)
    {
    }
   }
  }

package test;
 
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.channels.spi.AbstractSelector;
import java.nio.channels.spi.SelectorProvider;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
 
public class MultiThreadNIOEchoServer {
 public static Map<Socket, Long> geym_time_stat = new HashMap<Socket, Long>();
 
 class EchoClient {
  private LinkedList<ByteBuffer> outq;
 
  EchoClient() {
   outq = new LinkedList<ByteBuffer>();
  }
 
  public LinkedList<ByteBuffer> getOutputQueue() {
   return outq;
  }
 
  public void enqueue(ByteBuffer bb) {
   outq.addFirst(bb);
  }
 }
 
 class HandleMsg implements Runnable {
  SelectionKey sk;
  ByteBuffer bb;
 
  public HandleMsg(SelectionKey sk, ByteBuffer bb) {
   super();
   this.sk = sk;
   this.bb = bb;
  }
 
  @Override
  public void run() {
   // TODO Auto-generated method stub
   EchoClient echoClient = (EchoClient) sk.attachment();
   echoClient.enqueue(bb);
   sk.interestOps(SelectionKey.OP_READ | SelectionKey.OP_WRITE);
   selector.wakeup();
  }
 
 }
 
 private Selector selector;
 private ExecutorService tp = Executors.newCachedThreadPool();
 
 private void startServer() throws Exception {
  selector = SelectorProvider.provider().openSelector();
  ServerSocketChannel ssc = ServerSocketChannel.open();
  ssc.configureBlocking(false);
  InetSocketAddress isa = new InetSocketAddress(8000);
  ssc.socket().bind(isa);
  // 注册感兴趣的事件，此处对accpet事件感兴趣
  SelectionKey acceptKey = ssc.register(selector, SelectionKey.OP_ACCEPT);
  for (;;) {
   selector.select();
   Set readyKeys = selector.selectedKeys();
   Iterator i = readyKeys.iterator();
   long e = 0;
   while (i.hasNext()) {
    SelectionKey sk = (SelectionKey) i.next();
    i.remove();
    if (sk.isAcceptable()) {
     doAccept(sk);
    } else if (sk.isValid() && sk.isReadable()) {
     if (!geym_time_stat.containsKey(((SocketChannel) sk
       .channel()).socket())) {
      geym_time_stat.put(
        ((SocketChannel) sk.channel()).socket(),
        System.currentTimeMillis());
     }
     doRead(sk);
    } else if (sk.isValid() && sk.isWritable()) {
     doWrite(sk);
     e = System.currentTimeMillis();
     long b = geym_time_stat.remove(((SocketChannel) sk
       .channel()).socket());
     System.out.println("spend:" + (e - b) + "ms");
    }
   }
  }
 }
 
 private void doWrite(SelectionKey sk) {
  // TODO Auto-generated method stub
  SocketChannel channel = (SocketChannel) sk.channel();
  EchoClient echoClient = (EchoClient) sk.attachment();
  LinkedList<ByteBuffer> outq = echoClient.getOutputQueue();
  ByteBuffer bb = outq.getLast();
  try {
   int len = channel.write(bb);
   if (len == -1) {
    disconnect(sk);
    return;
   }
   if (bb.remaining() == 0) {
    outq.removeLast();
   }
  } catch (Exception e) {
   // TODO: handle exception
   disconnect(sk);
  }
  if (outq.size() == 0) {
   sk.interestOps(SelectionKey.OP_READ);
  }
 }
 
 private void doRead(SelectionKey sk) {
  // TODO Auto-generated method stub
  SocketChannel channel = (SocketChannel) sk.channel();
  ByteBuffer bb = ByteBuffer.allocate(8192);
  int len;
  try {
   len = channel.read(bb);
   if (len < 0) {
    disconnect(sk);
    return;
   }
  } catch (Exception e) {
   // TODO: handle exception
   disconnect(sk);
   return;
  }
  bb.flip();
  tp.execute(new HandleMsg(sk, bb));
 }
 
 private void disconnect(SelectionKey sk) {
  // TODO Auto-generated method stub
  //省略略干关闭操作
 }
 
 private void doAccept(SelectionKey sk) {
  // TODO Auto-generated method stub
  ServerSocketChannel server = (ServerSocketChannel) sk.channel();
  SocketChannel clientChannel;
  try {
   clientChannel = server.accept();
   clientChannel.configureBlocking(false);
   SelectionKey clientKey = clientChannel.register(selector,
     SelectionKey.OP_READ);
   EchoClient echoClinet = new EchoClient();
   clientKey.attach(echoClinet);
   InetAddress clientAddress = clientChannel.socket().getInetAddress();
   System.out.println("Accepted connection from "
     + clientAddress.getHostAddress());
  } catch (Exception e) {
   // TODO: handle exception
  }
 }
 
 public static void main(String[] args) {
  // TODO Auto-generated method stub
  MultiThreadNIOEchoServer echoServer = new MultiThreadNIOEchoServer();
  try {
   echoServer.startServer();
  } catch (Exception e) {
   // TODO: handle exception
  }
 
 }
 
}

server.accept(null,
    new CompletionHandler<AsynchronousSocketChannel, Object>() {
     final ByteBuffer buffer = ByteBuffer.allocate(1024);
 
     public void completed(AsynchronousSocketChannel result,
       Object attachment) {
      System.out.println(Thread.currentThread().getName());
      Future<Integer> writeResult = null;
      try {
       buffer.clear();
       result.read(buffer).get(100, TimeUnit.SECONDS);
       buffer.flip();
       writeResult = result.write(buffer);
      } catch (InterruptedException | ExecutionException e) {
       e.printStackTrace();
      } catch (TimeoutException e) {
       e.printStackTrace();
      } finally {
       try {
        server.accept(null, this);
        writeResult.get();
        result.close();
       } catch (Exception e) {
        System.out.println(e.toString());
       }
      }
     }
 
     @Override
     public void failed(Throwable exc, Object attachment) {
      System.out.println("failed: " + exc);
     }
    });