显示报文

package com.we;

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.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.util.Iterator;


public class HttpServer {
	public static void main(String[] args) throws IOException {
		
		 // 创建 ServerSocketChanne1，监听8080端口
		 ServerSocketChannel ssc = ServerSocketChannel.open(); 
		 ssc.socket().bind(new InetSocketAddress(8080));
		 // 设置为非阻塞模式
		 ssc.configureBlocking(false);
		 // 为ssc注册选择器
		 Selector selector = Selector.open();
		 ssc.register(selector, SelectionKey.OP_ACCEPT);
		 // 创建处理器
		 while (true) {
			// 等待请求，每次等待阻塞3s，超过3s后线程继续向下运行，如果传入0或者不传参数将直阻塞
			if (selector.select(3000) == 0) {
				continue;
			}
		    // 获取待处理的 SelectionKey
			Iterator<SelectionKey> keyIter = selector.selectedKeys().iterator();
			
			while (keyIter.hasNext()) {
				SelectionKey key  = keyIter.next();
				// 启动新线程处理SelectionKey
				new Thread(new HttpHandler(key)).run();
				// 处理完后， 从待处理的SelectionKey迭代器中移除当前所使用的key
				keyIter.remove();
			}
		 } 
	}
	
	private static class HttpHandler implements Runnable {
		private int bufferSize = 1024;
		private String localCharest = "UTF-8";
		private SelectionKey key;
		
		public HttpHandler(SelectionKey key) {
			this.key = key;
		}
		
		public void handleAccept() throws IOException {
			SocketChannel clientChannel = ((ServerSocketChannel)key.channel()).accept();
			clientChannel.configureBlocking(false);
			clientChannel.register(key.selector(), SelectionKey.OP_READ, ByteBuffer.allocate(bufferSize));
		}
		
		public void handleRead() throws IOException {
			// 获取channel
			SocketChannel sc = (SocketChannel)key.channel();
			// 获取buffer并重置
			ByteBuffer buffer = (ByteBuffer)key.attachment();
			buffer.clear();
			// 没有读到内容则关闭
			if (sc.read(buffer) == -1) {
				sc.close();
			} else {
				// 接收请求数据
				buffer.flip();
				String  receivedString = Charset.forName(localCharest).newDecoder().decode(buffer).toString();
			    // 控制台打印请求报文头
				String[] requestMessage = receivedString.split("\r\n");
				for (String s : requestMessage) {
					System.out.println(s);
					// 遇到空行说明报文头已经打完
					if (s.isEmpty()) {
						break;
					}	
				}
				
				// 控制台打印首行信息
				String[] firstLine = requestMessage[0].split(" ");
				System.out.println();
				System.out.println("Method:\t" + firstLine[0]);
				System.out.println("url:\t" + firstLine[1]);
				System.out.println("HTTP Version:\t" + firstLine[2]);
				System.out.println();
				
				// 返回客户端
				StringBuilder sendString = new StringBuilder();
				sendString.append("HTTP/1.1 200 OK\r\n");// 响应报文首行，200表示处理成功
				sendString.append("Content-Type:text/html;charset=" + localCharest + "\r\n");
				sendString.append("\r\n");// 报文头结束后加一个空行
				
				sendString.append("<html><head><title>显示报文</title></head></body>");
				sendString.append("接收到的请求报文是：<br/>" );
				
				for (String s : requestMessage) {
					sendString.append(s + "<br/>");
				}
				sendString.append("</body></html>");
				buffer = ByteBuffer.wrap(sendString.toString().getBytes(localCharest));
				sc.write(buffer);
				sc.close();
			}
			

			
			
		}

		@Override
		public void run() {
			try {
				// 接收到连接请求时
				if (key.isAcceptable()) {
					handleAccept();
				}
				// 读数据
				if (key.isReadable()) {
					handleRead();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
			
		}
	}

}