NIO入门实例
服务端
/*
* Copyright 2015-2101 Shouqi Limousine & chauffeur Group.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @Auther: qianll
* @Date: 2020年7月8日 下午5:51:14
* @Description:
*/
package com;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
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.util.Iterator;
import java.util.Set;
public class NIOServer {
/*标识数字*/
private int flag = 0;
/*缓冲区大小*/
private int BLOCK = 4096;
/*接受数据缓冲区*/
private ByteBuffer sendbuffer = ByteBuffer.allocate(BLOCK);
/*发送数据缓冲区*/
private ByteBuffer receivebuffer = ByteBuffer.allocate(BLOCK);
private Selector selector;
public NIOServer(int port) throws IOException {
// 打开服务器套接字通道
ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
// 服务器配置为非阻塞
serverSocketChannel.configureBlocking(false);
// 检索与此通道关联的服务器套接字
ServerSocket serverSocket = serverSocketChannel.socket();
// 进行服务的绑定
serverSocket.bind(new InetSocketAddress(port));
// 通过open()方法找到Selector
selector = Selector.open();
// 注册到selector，等待连接
serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
System.out.println("Server Start----8888:");
}
// 监听
private void listen() throws IOException {
while (true) {
// 选择一组键，并且相应的通道已经打开
selector.select();
// 返回此选择器的已选择键集。
Set selectionKeys = selector.selectedKeys();
Iterator iterator = selectionKeys.iterator();
while (iterator.hasNext()) {
SelectionKey selectionKey = iterator.next();
iterator.remove();
handleKey(selectionKey);
}
}
}
// 处理请求
private void handleKey(SelectionKey selectionKey) throws IOException {
// 接受请求
ServerSocketChannel server = null;
SocketChannel client = null;
String receiveText;
String sendText;
int count=0;
// 测试此键的通道是否已准备好接受新的套接字连接。
if (selectionKey.isAcceptable()) {
// 返回为之创建此键的通道。
server = (ServerSocketChannel) selectionKey.channel();
// 接受到此通道套接字的连接。
// 此方法返回的套接字通道（如果有）将处于阻塞模式。
client = server.accept();
// 配置为非阻塞
client.configureBlocking(false);
// 注册到selector，等待连接
client.register(selector, SelectionKey.OP_READ);
} else if (selectionKey.isReadable()) {
// 返回为之创建此键的通道。
client = (SocketChannel) selectionKey.channel();
//将缓冲区清空以备下次读取
receivebuffer.clear();
//读取服务器发送来的数据到缓冲区中
count = client.read(receivebuffer);
if (count > 0) {
receiveText = new String( receivebuffer.array(),0,count);
System.out.println("服务器端接受客户端数据--:"+receiveText);
client.register(selector, SelectionKey.OP_WRITE);
}
} else if (selectionKey.isWritable()) {
//将缓冲区清空以备下次写入
sendbuffer.clear();
// 返回为之创建此键的通道。
client = (SocketChannel) selectionKey.channel();
sendText="message from server--" + flag++;
//向缓冲区中输入数据
sendbuffer.put(sendText.getBytes());
//将缓冲区各标志复位,因为向里面put了数据标志被改变要想从中读取数据发向服务器,就要复位
sendbuffer.flip();
//输出到通道
client.write(sendbuffer);
System.out.println("服务器端向客户端发送数据--："+sendText);
client.register(selector, SelectionKey.OP_READ);
}
}
/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
int port = 8888;
NIOServer server = new NIOServer(port);
server.listen();
}
}
客户端
/*
* Copyright 2015-2101 Shouqi Limousine & chauffeur Group.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @Auther: qianll
* @Date: 2020年7月8日 下午5:50:24
* @Description:
*/
package com;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;
public class NIOClient {
/*标识数字*/
private static int flag = 0;
/*缓冲区大小*/
private static int BLOCK = 4096;
/*接受数据缓冲区*/
private static ByteBuffer sendbuffer = ByteBuffer.allocate(BLOCK);
/*发送数据缓冲区*/
private static ByteBuffer receivebuffer = ByteBuffer.allocate(BLOCK);
/*服务器端地址*/
private final static InetSocketAddress SERVER_ADDRESS = new InetSocketAddress(
"localhost", 8888);
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
// 打开socket通道
SocketChannel socketChannel = SocketChannel.open();
// 设置为非阻塞方式
socketChannel.configureBlocking(false);
// 打开选择器
Selector selector = Selector.open();
// 注册连接服务端socket动作
socketChannel.register(selector, SelectionKey.OP_CONNECT);
// 连接
socketChannel.connect(SERVER_ADDRESS);
// 分配缓冲区大小内存
Set selectionKeys;
Iterator iterator;
SelectionKey selectionKey;
SocketChannel client;
String receiveText;
String sendText;
int count=0;
while (true) {
//选择一组键，其相应的通道已为 I/O 操作准备就绪。
//此方法执行处于阻塞模式的选择操作。
selector.select();
//返回此选择器的已选择键集。
selectionKeys = selector.selectedKeys();
//System.out.println(selectionKeys.size());
iterator = selectionKeys.iterator();
while (iterator.hasNext()) {
selectionKey = iterator.next();
if (selectionKey.isConnectable()) {
System.out.println("client connect");
client = (SocketChannel) selectionKey.channel();
// 判断此通道上是否正在进行连接操作。
// 完成套接字通道的连接过程。
if (client.isConnectionPending()) {
client.finishConnect();
System.out.println("完成连接!");
sendbuffer.clear();
sendbuffer.put("Hello,Server".getBytes());
sendbuffer.flip();
client.write(sendbuffer);
}
client.register(selector, SelectionKey.OP_READ);
} else if (selectionKey.isReadable()) {
client = (SocketChannel) selectionKey.channel();
//将缓冲区清空以备下次读取
receivebuffer.clear();
//读取服务器发送来的数据到缓冲区中
count=client.read(receivebuffer);
if(count>0){
receiveText = new String( receivebuffer.array(),0,count);
System.out.println("客户端接受服务器端数据--:"+receiveText);
//注册写事件同时触发写事件
client.register(selector, SelectionKey.OP_WRITE);
}
} else if (selectionKey.isWritable()) {
sendbuffer.clear();
client = (SocketChannel) selectionKey.channel();
sendText = "message from client--" + (flag++);
sendbuffer.put(sendText.getBytes());
//将缓冲区各标志复位,因为向里面put了数据标志被改变要想从中读取数据发向服务器,就要复位
sendbuffer.flip();
client.write(sendbuffer);
System.out.println("客户端向服务器端发送数据--："+sendText);
client.register(selector, SelectionKey.OP_READ);
}
}
selectionKeys.clear();
}
}
}