netty BIO、NIO、AIO简单例子

客官°小女子只卖身不卖艺 2022-02-01 10:57 270阅读 0赞

## socket ##

套接字分4个部分  
1、服务器监听  
2、客户端发起请求  
3、服务器确认  
4、客户端确认

# #

## **BIO** ##

同步阻塞

public class Server {
    
    	final static int PORT = 8765;
    
    	public static void main(String[] args) {
    		ServerSocket server = null;
    		BufferedReader in = null;
    		PrintWriter out = null;
    		try {
    			server = new ServerSocket(PORT);
    			System.out.println("server start");
    			Socket socket = null;
                //这里是自定义了一个线程池
    			HandlerExecutorPool executorPool = new HandlerExecutorPool(50, 1000);
    			while(true){
    				socket = server.accept();
    				executorPool.execute(new ServerHandler(socket));
    			}
    		} catch (Exception e) {
    			e.printStackTrace();
    		} finally {
    			if(in != null){
    				try {
    					in.close();
    				} catch (Exception e1) {
    					e1.printStackTrace();
    				}
    			}
    			if(out != null){
    				try {
    					out.close();
    				} catch (Exception e2) {
    					e2.printStackTrace();
    				}
    			}
    			if(server != null){
    				try {
    					server.close();
    				} catch (Exception e3) {
    					e3.printStackTrace();
    				}
    			}
    			server = null;				
    		}
    	}
    }

public class Client {
    	
    	final static String ADDRESS = "127.0.0.1";
    	final static int PORT =8765;
    	
    	public static void main(String[] args) {
    		Socket socket = null;
    		BufferedReader in = null;
    		PrintWriter out = null;
    		try {
    			socket = new Socket(ADDRESS, PORT);
    			in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
    			out = new PrintWriter(socket.getOutputStream(), true);
    			
    			out.println("Client request");
    			String response = in.readLine();
    			System.out.println("Client:" + response);
    		}  catch (Exception e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		} finally {
    			if(in != null){
    				try {
    					in.close();
    				} catch (Exception e1) {
    					e1.printStackTrace();
    				}
    			}
    			if(out != null){
    				try {
    					out.close();
    				} catch (Exception e2) {
    					e2.printStackTrace();
    				}
    			}
    			if(socket != null){
    				try {
    					socket.close();
    				} catch (Exception e3) {
    					e3.printStackTrace();
    				}
    			}
    			socket = null;				
    		}
    	}
    }

public class ServerHandler implements Runnable {
    
    	private Socket socket;
    	public ServerHandler (Socket socket){
    		this.socket = socket;
    	}
    	
    	@Override
    	public void run() {
    		BufferedReader in = null;
    		PrintWriter out = null;
    		try {
    			in = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));
    			out = new PrintWriter(this.socket.getOutputStream(), true);
    			String body = null;
    			while(true){
    				body = in.readLine();
    				if(body == null) break;
    				System.out.println("Server:" + body);
    				out.println("Server response");
    			}
    		} catch (Exception e) {
    			e.printStackTrace();
    		} finally {
    			if(in != null){
    				try {
    					in.close();
    				} catch (Exception e1) {
    					e1.printStackTrace();
    				}
    			}
    			if(out != null){
    				try {
    					out.close();
    				} catch (Exception e2) {
    					e2.printStackTrace();
    				}
    			}
    			if(socket != null){
    				try {
    					socket.close();
    				} catch (Exception e3) {
    					e3.printStackTrace();
    				}
    			}
    			socket = null;			
    		}
    	}
    }

## **NIO** ##

public class Server implements Runnable{
    	//1 多路复用器（管理所有的通道）
    	private Selector seletor;
    	//2 建立缓冲区
    	private ByteBuffer readBuf = ByteBuffer.allocate(1024);
    	//3 
    	private ByteBuffer writeBuf = ByteBuffer.allocate(1024);
    
    	public Server(int port){
    		try {
    			//1 打开路复用器
    			this.seletor = Selector.open();
    			//2 打开服务器通道
    			ServerSocketChannel ssc = ServerSocketChannel.open();
    			//3 设置服务器通道为非阻塞模式
    			ssc.configureBlocking(false);
    			//4 绑定地址
    			ssc.bind(new InetSocketAddress(port));
    			//5 把服务器通道注册到多路复用器上，并且监听阻塞事件
    			ssc.register(this.seletor, SelectionKey.OP_ACCEPT);
    			
    			System.out.println("Server start, port :" + port);
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    	}
    
    	@Override
    	public void run() {
    		while(true){
    			try {
    				//1 必须要让多路复用器开始监听
    				this.seletor.select();
    				//2 返回多路复用器已经选择的结果集
    				Iterator<SelectionKey> keys = this.seletor.selectedKeys().iterator();
    				//3 进行遍历
    				while(keys.hasNext()){
    					//4 获取一个选择的元素
    					SelectionKey key = keys.next();
    					//5 直接从容器中移除就可以了
    					keys.remove();
    					//6 如果是有效的
    					if(key.isValid()){
    						//7 如果为阻塞状态
    						if(key.isAcceptable()){
    							this.accept(key);
    						}
    						//8 如果为可读状态
    						if(key.isReadable()){
    							this.read(key);
    						}
    						//9 写数据
    						if(key.isWritable()){
    							//this.write(key); //ssc
    						}
    					}
    				}
    			} catch (IOException e) {
    				e.printStackTrace();
    			}
    		}
    	}
    	
    	private void write(SelectionKey key){
    		//ServerSocketChannel ssc =  (ServerSocketChannel) key.channel();
    		//ssc.register(this.seletor, SelectionKey.OP_WRITE);
    	}
    
    	private void read(SelectionKey key) {
    		try {
    			//1 清空缓冲区旧的数据
    			this.readBuf.clear();
    			//2 获取之前注册的socket通道对象
    			SocketChannel sc = (SocketChannel) key.channel();
    			//3 读取数据
    			int count = sc.read(this.readBuf);
    			//4 如果没有数据
    			if(count == -1){
    				key.channel().close();
    				key.cancel();
    				return;
    			}
    			//5 有数据则进行读取 读取之前需要进行复位方法(把position 和limit进行复位)
    			this.readBuf.flip();
    			//6 根据缓冲区的数据长度创建相应大小的byte数组，接收缓冲区的数据
    			byte[] bytes = new byte[this.readBuf.remaining()];
    			//7 接收缓冲区数据
    			this.readBuf.get(bytes);
    			//8 打印结果
    			String body = new String(bytes).trim();
    			System.out.println("Server : " + body);
    			// 9..可以写回给客户端数据
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    		
    	}
    
    	private void accept(SelectionKey key) {
    		try {
    			//1 获取服务通道
    			ServerSocketChannel ssc =  (ServerSocketChannel) key.channel();
    			//2 执行阻塞方法
    			SocketChannel sc = ssc.accept();
    			//3 设置阻塞模式
    			sc.configureBlocking(false);
    			//4 注册到多路复用器上，并设置读取标识
    			sc.register(this.seletor, SelectionKey.OP_READ);
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    	}
    	
    	public static void main(String[] args) {
    		new Thread(new Server(8765)).start();
    	}
    }

public class Client {
    
    	//需要一个Selector 
    	public static void main(String[] args) {
    		
    		//创建连接的地址
    		InetSocketAddress address = new InetSocketAddress("127.0.0.1", 8765);
    		//声明连接通道
    		SocketChannel sc = null;
    		//建立缓冲区
    		ByteBuffer buf = ByteBuffer.allocate(1024);
    		
    		try {
    			//打开通道
    			sc = SocketChannel.open();
    			//进行连接
    			sc.connect(address);
    			while(true){
    				//定义一个字节数组，然后使用系统录入功能：
    				byte[] bytes = new byte[1024];
    				System.in.read(bytes);
    				
    				//把数据放到缓冲区中
    				buf.put(bytes);
    				//对缓冲区进行复位
    				buf.flip();
    				//写出数据
    				sc.write(buf);
    				//清空缓冲区数据
    				buf.clear();
    			}
    		} catch (IOException e) {
    			e.printStackTrace();
    		} finally {
    			if(sc != null){
    				try {
    					sc.close();
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    			}
    		}
    		
    	}
    	
    }

JAVA 中jdk Buffer使用

public static void main(String[] args) {
    		// 1 基本操作
    		//创建指定长度的缓冲区
    		IntBuffer buf = IntBuffer.allocate(10);
    		buf.put(13);// position位置：0 - > 1
    		buf.put(21);// position位置：1 - > 2
    		buf.put(35);// position位置：2 - > 3
    		//把位置复位为0，也就是position位置：3 - > 0
    		buf.flip();
    		System.out.println("使用flip复位：" + buf);
    		System.out.println("容量为: " + buf.capacity());	//容量一旦初始化后不允许改变（warp方法包裹数组除外）
    		System.out.println("限制为: " + buf.limit());		//由于只装载了三个元素,所以可读取或者操作的元素为3 则limit=3
    		
    		
    		System.out.println("获取下标为1的元素：" + buf.get(1));
    		System.out.println("get(index)方法，position位置不改变：" + buf);
    		buf.put(1, 4);
    		System.out.println("put(index, change)方法，position位置不变：" + buf);;
    		
    		for (int i = 0; i < buf.limit(); i++) {
    			//调用get方法会使其缓冲区位置（position）向后递增一位
    			System.out.print(buf.get() + "\t");
    		}
    		System.out.println("buf对象遍历之后为: " + buf);
    		
    		
    		// 2 wrap方法使用
    		/**
    		//  wrap方法会包裹一个数组: 一般这种用法不会先初始化缓存对象的长度，因为没有意义，最后还会被wrap所包裹的数组覆盖掉。 
    		//  并且wrap方法修改缓冲区对象的时候，数组本身也会跟着发生变化。                     
    		int[] arr = new int[]{1,2,5};
    		IntBuffer buf1 = IntBuffer.wrap(arr);
    		System.out.println(buf1);
    		
    		IntBuffer buf2 = IntBuffer.wrap(arr, 0 , 2);
    		//这样使用表示容量为数组arr的长度，但是可操作的元素只有实际进入缓存区的元素长度
    		System.out.println(buf2);
    		*/
    		
    		
    		// 3 其他方法
    		/**
    		IntBuffer buf1 = IntBuffer.allocate(10);
    		int[] arr = new int[]{1,2,5};
    		buf1.put(arr);
    		System.out.println(buf1);
    		//一种复制方法
    		IntBuffer buf3 = buf1.duplicate();
    		System.out.println(buf3);
    		
    		//设置buf1的位置属性
    		//buf1.position(0);
    		buf1.flip();
    		System.out.println(buf1);
    		
    		System.out.println("可读数据为：" + buf1.remaining());
    		
    		int[] arr2 = new int[buf1.remaining()];
    		//将缓冲区数据放入arr2数组中去
    		buf1.get(arr2);
    		for(int i : arr2){
    			System.out.print(Integer.toString(i) + ",");
    		}
    		*/
    	}

## **AIO** ##

public class Server {
    	//线程池
    	private ExecutorService executorService;
    	//线程组
    	private AsynchronousChannelGroup threadGroup;
    	//服务器通道
    	public AsynchronousServerSocketChannel assc;
    	
    	public Server(int port){
    		try {
    			//创建一个缓存池
    			executorService = Executors.newCachedThreadPool();
    			//创建线程组
    			threadGroup = AsynchronousChannelGroup.withCachedThreadPool(executorService, 1);
    			//创建服务器通道
    			assc = AsynchronousServerSocketChannel.open(threadGroup);
    			//进行绑定socket连接信息
    			assc.bind(new InetSocketAddress(port));
    			
    			System.out.println("server start , port : " + port);
    			//进行阻塞
    			assc.accept(this, new ServerCompletionHandler());
    			//一直阻塞 不让服务器停止
    			Thread.sleep(Integer.MAX_VALUE);
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    	
    	public static void main(String[] args) {
    		Server server = new Server(8765);
    	}
    	
    }

public class Client implements Runnable{
    
    	private AsynchronousSocketChannel asc ;
    	
    	public Client() throws Exception {
    		asc = AsynchronousSocketChannel.open();
    	}
    	
    	public void connect(){
    		asc.connect(new InetSocketAddress("127.0.0.1", 8765));
    	}
    	
    	public void write(String request){
    		try {
    			asc.write(ByteBuffer.wrap(request.getBytes())).get();
    			read();
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    
    	private void read() {
    		ByteBuffer buf = ByteBuffer.allocate(1024);
    		try {
    			asc.read(buf).get();
    			buf.flip();
    			byte[] respByte = new byte[buf.remaining()];
    			buf.get(respByte);
    			System.out.println(new String(respByte,"utf-8").trim());
    		} catch (InterruptedException e) {
    			e.printStackTrace();
    		} catch (ExecutionException e) {
    			e.printStackTrace();
    		} catch (UnsupportedEncodingException e) {
    			e.printStackTrace();
    		}
    	}
    	
    	@Override
    	public void run() {
    		while(true){
    		}
    	}
    	
    	public static void main(String[] args) throws Exception {
    		Client c1 = new Client();
    		c1.connect();
    		
    		Client c2 = new Client();
    		c2.connect();
    		
    		Client c3 = new Client();
    		c3.connect();
    		
    		new Thread(c1, "c1").start();
    		new Thread(c2, "c2").start();
    		new Thread(c3, "c3").start();
    		
    		Thread.sleep(1000);
    		
    		c1.write("c1 aaa");
    		c2.write("c2 bbbb");
    		c3.write("c3 ccccc");
    	}
    	
    }

public class ServerCompletionHandler implements CompletionHandler<AsynchronousSocketChannel, Server> {
    
    	@Override
    	public void completed(AsynchronousSocketChannel asc, Server attachment) {
    		//当有下一个客户端接入的时候 直接调用Server的accept方法，这样反复执行下去，保证多个客户端都可以阻塞
    		attachment.assc.accept(attachment, this);
    		read(asc);
    	}
    
    	private void read(final AsynchronousSocketChannel asc) {
    		//读取数据
    		ByteBuffer buf = ByteBuffer.allocate(1024);
    		asc.read(buf, buf, new CompletionHandler<Integer, ByteBuffer>() {
    			@Override
    			public void completed(Integer resultSize, ByteBuffer attachment) {
    				//进行读取之后,重置标识位
    				attachment.flip();
    				//获得读取的字节数
    				System.out.println("Server -> " + "收到客户端的数据长度为:" + resultSize);
    				//获取读取的数据
    				String resultData = new String(attachment.array()).trim();
    				System.out.println("Server -> " + "收到客户端的数据信息为:" + resultData);
    				String response = "服务器响应, 收到了客户端发来的数据: " + resultData;
    				write(asc, response);
    			}
    			@Override
    			public void failed(Throwable exc, ByteBuffer attachment) {
    				exc.printStackTrace();
    			}
    		});
    	}
    	
    	private void write(AsynchronousSocketChannel asc, String response) {
    		try {
    			ByteBuffer buf = ByteBuffer.allocate(1024);
    			buf.put(response.getBytes());
    			buf.flip();
    			asc.write(buf).get();
    		} catch (InterruptedException e) {
    			e.printStackTrace();
    		} catch (ExecutionException e) {
    			e.printStackTrace();
    		}
    	}
    	
    	@Override
    	public void failed(Throwable exc, Server attachment) {
    		exc.printStackTrace();
    	}
    
    }