运用JavaNIO提高做事端按次的性能

1、运用java nio提高做事端按次的性能星散具体的jova socket编程，探求使用n10前进办事端步伐的坚守的问题。java nio增长了新的socketchannel > serversocketchannel等类來供给対成立高违拗的 效力端举措的赞成。socketchannel、serversocketchannel能够在非壅塞的形式下工作，它 们但凡selectable的类。在树立服务器或者两端件时,引荐应用java n10o在传统的internet编程屮，我们一样平常使用一个专门使用线程(thread)来措置一个 socket邻接，颠末运用ni0, 个可以或许很少几个sock

2、et线程便可以处理不计其数个勾当的 socket 邻接。一样平常悄况下，通过 serversocketchannel. open ()获得一个 serversocketchannel 的实 例，经由过程 socketchannel. open 笼统 serversocketchannel. accept ()失掉一个 socketchannel实例。要使serversocketchannel笼统socketchannel在卄缠闭的内容下垄断， 可以调用sorversockctchannel. conf iguroblocking (false);或者socketchannel. configu

3、reblocking (false);语句来抵达目的。一般状况下,效劳端可使用非壅塞的serversocketchannel,多么，做 事真个措沌便可以更易地同时处置惩罚多个socket线程。下面我们来看一个赏析例子，这个例子运用了 serversocketchannel socketchannel斥地 了一个非壅塞的、能处置多线程的echo效能端措施，赐教例12-14o【递次源代码】1 / = program discription =2 / 程序名称：示例 12-14 : socketchanneldemo.java3 / 程序目的：学习 java nio#socketchannel4 /

4、=565 import java.nio.bytebuffer;6 import java.nio.channels.serversocketchannel;7 import java.nio.channels.socketchannel;8 import java.nio.channels.selector;9 import java.nio.channels.selectionkey;10 import java.nio.channels.selectablechannel;1311 import .socket;12 import .serversocket;13 import .ine

5、tsocketaddress;14 i mport java.uti 1.iterator;1815 public class socketchanneldemo2016 17 public static int port.number = 23;/监听端口18 serversocketchannel serverchannel;19 serversocket serversocket;20 selector selector;21 private bytebuffer buffer = bytebuffer.allocatedirect (1024);2722 public static v

6、oid main (string args)23 throws exception24 25 socketchanneldemo server=new socketchanneldemo();26 scrvcr.init(args);27 server.startwork();34353637 public void init (string argv)throws exception38 39 int port = port_number;4040 if (argv.length > 0) 41 port = integer.parselnt (argv 0);434445 syste

7、m.out.println ("listening on port" + port);4646 / 分配-个 serversocketchannel47 serverchannel = serversocketchannel.open();48 / 从 serversocketchannel 里获得一个对应的 socket49 serversocket = serverchannel.socket();50 / 生成一个 selector51 selector = selector.open();5352 /把socket绑定到端口上53 serversocket.bind

8、 (new inetsocketaddress (port);54 /serverchannel 为非 bolck55 serverchannel.configureblocking (false);5856 / 通过 selector 注册 serversocetchannel57 serverchannel.register (selector, selectionkey.op_accept);61626364 public void startwork()throws exception6565 66 while (true) 6867 int n = selector.select()

9、;/获得 io 准备就绪的 channel 数虽7068 if(n = 0) 69 continue; /没有channel准备就绪，继续执行70 7471 / 用一个 iterator 返回 selector 的 selectedkeys72 iterator it = selector.selectedkeys().iterator();7773 / 处理每一个 sclcctionkcy74 while (it.hasnext() 75 selectionkey key = (selectionkey) it.next();8182/判断是否有新的连接到达83 if (key.isacce

10、ptable() 84 返回 selectionkey 的 serversocketchannel85 serversocketchannel server = (serversocketchannel) key.channel();86 socketchannel channel = server.accept();8787 registerchannel (selector, channel,88 selectionkey.op_read);9089 dowork (channel);90 9394/判断是否有数据在此channel里需要读取95 if (key.isreadable()

11、9696 processdata (key);9897 )10098 删除 selectedkeys99 it.remove();100 101 102 103 protected void registerchannel (selector selector,104 selectablechannel channel, int ops)105 throws exception106 107 if (channel = null) 108 return;109 113114110 channel.configureblocking (false);116117 channel.register

12、 (selector, ops);118 119119 处理接收的数据120 protected void proccssdata (sclcctionkcy key)121 throws exception122 124125123 socketchannel socketchannel = (socketchannel) key.channel();124 int count;128125 buffer.clear(); / 清空 buffer130131读取所有的数据132 while (count = socketchannel.read (buffer) > 0) 133 bu

13、ffer.flip();134134 / send the data, don't assume it goes all at once135 while (buffer.hasremainingo)136 137 如果收到回午键，贝ij在返回的字符前增加ccho$字样138 if(buffer.get()=(char) 13)139 140 buffer.clear();141 buffer.put(mechofckpdoquot;.getbytes();142 buffer.flipo;144143 144 socketchannel.write (buffer);/在 socket 里写数据145 148146 buffer.clear(); / 清空 buffer147 151148 if (count < 0) 153/count<0,说明已经读取完毕154 socketchannel.close();155 156 157158157 private void do work (socketchannel channel)throws exception158 159 buffer.clear();16