標籤：pen bin ret org pool r.java 編程 oca decode
package block;
import java.io.*;
import java.nio.*;
import java.nio.channels.*;
import java.nio.charset.*;
import java.net.*;
import java.util.*;
import java.util.concurrent.*;
public class EchoServer {
private int port=8000;
private ServerSocketChannel serverSocketChannel = null;
private ExecutorService executorService;
private static final int POOL_MULTIPLE = 4;
public EchoServer() throws IOException {
executorService= Executors.newFixedThreadPool(
Runtime.getRuntime().availableProcessors() * POOL_MULTIPLE);
serverSocketChannel= ServerSocketChannel.open();
serverSocketChannel.socket().setReuseAddress(true);
serverSocketChannel.socket().bind(new InetSocketAddress(port));
System.out.println("伺服器啟動");
}
public void service() {
while (true) {
SocketChannel socketChannel=null;
try {
socketChannel = serverSocketChannel.accept();
executorService.execute(new Handler(socketChannel));
}catch (IOException e) {
e.printStackTrace();
}
}
}
public static void main(String args[])throws IOException {
new EchoServer().service();
}
}
class Handler implements Runnable{
private SocketChannel socketChannel;
public Handler(SocketChannel socketChannel){
this.socketChannel=socketChannel;
}
public void run(){
handle(socketChannel);
}
public void handle(SocketChannel socketChannel){
try {
Socket socket=socketChannel.socket();
System.out.println("接收到客戶串連，來自: " +
socket.getInetAddress() + ":" +socket.getPort());
BufferedReader br =getReader(socket);
PrintWriter pw = getWriter(socket);
String msg = null;
while ((msg = br.readLine()) != null) {
System.out.println(msg);
pw.println(echo(msg));
if (msg.equals("bye"))
break;
}
}catch (IOException e) {
e.printStackTrace();
}finally {
try{
if(socketChannel!=null)socketChannel.close();
}catch (IOException e) {e.printStackTrace();}
}
}
private PrintWriter getWriter(Socket socket)throws IOException{
OutputStream socketOut = socket.getOutputStream();
return new PrintWriter(socketOut,true);
}
private BufferedReader getReader(Socket socket)throws IOException{
InputStream socketIn = socket.getInputStream();
return new BufferedReader(new InputStreamReader(socketIn));
}
public String echo(String msg) {
return "echo:" + msg;
}
}
/****************************************************
* 孫衛琴 *
* 來源：<<Java網路編程精解>> *
* 支援人員網址：www.javathinker.org *
***************************************************/
EchoServer 類的構造負責建立線程池，啟動伺服器，把它綁定到一個本地連接埠。EchoServer類的service()方法負責接收客戶的串連。每接收一個客戶串連，就把它交給線程池來處理，線程池取出一個閒置線程，來執行Handler對象的run()方法。Handler類的handle()負責與客戶通訊。該方法先獲得與SocketChannel關聯的Socket對象，然後從Socket對象中得到輸入資料流與輸出資料流，再接收和發送資料。
SocketChanle實際上也是提供了read(ByteBuffer buffer),但是通過它來讀取一行字元比較麻煩。一下radLine()方法就通過SocketChannel的read(ByteBuffer buffer)方法來讀取一行字串。它的作用與BufferReader的readLine()方法等價的。
//*******************
public String readLine(SocketChannel socketChannel)throws IOException{
ByteBuffer buffer = ByteBuffer.allocate(1024);
ByteBuffer tempBuffer =ByteBuffer.allocate(1);
boolean isLine = false;
boolean isEnd = false;
String data = null;
while(!isLine && !isEnd){
tempBuffer.clear();
int n = socketChannel.read(tempBuffer);
if(n==-1){
isEnd = true;
break;
}
if(n==0) continue;
tempBuffer.flip();
buffer.put(tempBuffer);
buffer.flip();
Charset charset = Charset.forName("GBK");
CharBuffer charBuffer = charset.decode(buffer);
data = charBuffer.toString();
if(data.indexOf("\r\n")!=-1){
isLine = true;
data = data.substring(0,data.indexOf("\r\n"));
break;
}
buffer.position(buffer.limit());
buffer.limit(buffer.capacity());
}
return data;
}
EchoServer.java (阻塞模式)
