java socket nio编程

上次写了一个socket的基本编程，但是有个问题，阻塞特别严重，于是小编便去找了nio学习了一下...

public class TimeServer {

    public static void main(String[] args) {
        MultipexerTimeServer timersServer=new MultipexerTimeServer("192.168.1.102", 8400);
        new Thread(timersServer, "nio-多路复用器").start();
    }
    
}

public class MultipexerTimeServer implements Runnable {

    private Selector selector;
    
    private ServerSocketChannel serverSocketChannel;
    
    private volatile boolean stop;
    
    public MultipexerTimeServer(String addr,int point){
        try {
            selector=Selector.open();
            serverSocketChannel=ServerSocketChannel.open();
            serverSocketChannel.socket().bind(new InetSocketAddress(addr, point));
            serverSocketChannel.configureBlocking(false);
            serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
            System.out.println("socket服务端:"+serverSocketChannel.socket().getInetAddress()+":"+serverSocketChannel.socket().getLocalPort()+"");
        } catch (Exception e) {
            e.printStackTrace();
            System.exit(1);
        }
    }
    
    public void stop(){
        this.stop=true;
    }
    
    @Override
    public void run() {
        while(!stop){
            try {
                selector.select(1000);
                Set<SelectionKey> selectionKeys=selector.selectedKeys();
                if(selectionKeys !=null && selectionKeys.size()>0){
                    Iterator<SelectionKey> it=selectionKeys.iterator();
                    SelectionKey key=null;
                    while(it.hasNext()){
                        key=it.next();
                        it.remove();
                        try {
                            handleInput(key);
                        } catch (Exception e) {
                            if(key!=null){
                                key.cancel();
                                if(key.channel()!=null){
                                    try {
                                        key.channel().close();
                                    } catch (Exception e1) {
                                        e1.printStackTrace();
                                    }
                                }
                            }
                        }
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        if(selector!=null){
            try {
                selector.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    private void handleInput(SelectionKey key) throws IOException{
        if(key.isValid()){
            //处理新接入的请求
            if(key.isAcceptable()){
                ServerSocketChannel ssc=(ServerSocketChannel)key.channel();
                SocketChannel sc=ssc.accept();
                sc.configureBlocking(false);
                sc.register(selector,SelectionKey.OP_READ);
                SocketAddress clientAddress =sc.getRemoteAddress();  
                System.out.println("socket链接新客户端:" + clientAddress);  
            }
            if(key.isReadable()){
                //读取数据
                SocketChannel sc=(SocketChannel)key.channel();
                ByteBuffer readBuffer=ByteBuffer.allocate(1024);
                int readBytes=sc.read(readBuffer);
                if(readBytes>0){
                    readBuffer.flip();
                    byte[] bytes=new byte[readBuffer.remaining()];
                    readBuffer.get(bytes);
                    String body=new String(bytes, Charset.forName("GBK"));
                    SocketAddress clientAddress =sc.getRemoteAddress();  
                    System.out.println("socket链接老客户端:" + clientAddress);  
                    System.out.println("服务器接收数据:"+body);
                    //然后回写点数据给客服端
                    SimpleDateFormat  dateFormat=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                    String time=dateFormat.format(new Date());
                    String res="来自与服务端的回应,时间:"+ time;
                    doWrite(sc,res);
                }else if(readBytes<0){
                    key.cancel();
                    sc.close();
                }else{
                    //System.out.println("服务器收到0字节数据...");
                }
            }
        }
    }
    
    private void doWrite(SocketChannel sc,String res) throws IOException{
        if(res!=null && res.trim().length()>0){
            byte[] bytes=res.getBytes();
            ByteBuffer byteBuffer=ByteBuffer.allocate(1024);
            byteBuffer.put(bytes);
            byteBuffer.flip();
            sc.write(byteBuffer);
        }
    }
    

代码不想解释太多，有空整理一下nio的基本概念...