java nio http服务器（1）读取http请求

通过nio读取http的头信息。直接看代码：

package com.hcserver.conn;import java.io.BufferedReader;import java.io.ByteArrayOutputStream;import java.io.StringReader;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.util.Iterator;public class Server {public void start() throws Exception {Selector selector = Selector.open();ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();serverSocketChannel.configureBlocking(false);serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);serverSocketChannel.socket().setReuseAddress(true);serverSocketChannel.socket().bind(new InetSocketAddress(8084));while(true){while (selector.select() > 0) {Iterator<SelectionKey> selectedKeys = selector.selectedKeys() .iterator();while (selectedKeys.hasNext()) {SelectionKey key = selectedKeys.next();if (key.isAcceptable()) {ServerSocketChannel ssc = (ServerSocketChannel) key.channel();SocketChannel channel = ssc.accept();if(channel != null){channel.configureBlocking(false);channel.register(selector, SelectionKey.OP_READ);// 客户socket通道注册读操作}} else if (key.isReadable()) {SocketChannel channel = (SocketChannel) key.channel();channel.configureBlocking(false);String receive = receive(channel);BufferedReader b = new BufferedReader(new StringReader(receive));String s = b.readLine();while (s !=null) {System.out.println(s);s = b.readLine();}b.close();channel.register(selector, SelectionKey.OP_WRITE);} else if (key.isWritable()) {SocketChannel channel = (SocketChannel) key.channel();String hello = "hello world...";ByteBuffer buffer = ByteBuffer.allocate(1024);byte[] bytes = hello.getBytes();buffer.put(bytes);buffer.flip();channel.write(buffer);channel.shutdownInput();channel.close();}}}}}// 接受数据private String receive(SocketChannel socketChannel) throws Exception {ByteBuffer buffer = ByteBuffer.allocate(1024);byte[] bytes = null;int size = 0;ByteArrayOutputStream baos = new ByteArrayOutputStream();while ((size = socketChannel.read(buffer)) > 0) {buffer.flip();bytes = new byte[size];buffer.get(bytes);baos.write(bytes);buffer.clear();}bytes = baos.toByteArray();return new String(bytes);}}

package com.hcserver;import com.hcserver.conn.Server;public class ServerStartUp {/** * @param args * @throws Exception  */public static void main(String[] args) throws Exception {Server server = new Server();server.start();}}

运行代码，然后打开浏览器在地址栏输入：http://localhost:8084/hello?aa=1&bb=2,
回车后浏览器显示hello world 。而后台则输出http请求头信息：如下所示：

GET /hello?aa=1&bb=2 HTTP/1.1Accept: text/html, application/xhtml+xml, */*Accept-Language: zh-CNUser-Agent: Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/6.0)Accept-Encoding: gzip, deflateHost: localhost:8084DNT: 1Connection: Keep-Alive