システムプログラム（第8回）: スレッドによる複数のクライアントに対するサービスの同時提供(Java版)

                                       筑波大学 システム情報系 情報工学域
                                       新城 靖
                                       <yas@cs.tsukuba.ac.jp>

このページは、次の URL にあります。
http://www.coins.tsukuba.ac.jp/~syspro/2019/2019-06-12 /echo-server-java-thread.html
あるいは、次のページから手繰っていくこともできます。
http://www.coins.tsukuba.ac.jp/~syspro/2019/
http://www.coins.tsukuba.ac.jp/~yas/

EchoServer.java

  23:	        public static void echo_server( int portno ) throws IOException
  24:	        {
  25:	                ServerSocket acc = new ServerSocket( portno );
  26:	                print_my_host_port( portno );
  27:	                while( true )
  28:	                {
  29:	                        stdout.printf("accepting incoming connections (hash== %s) ...\n", 
  30:	                                      acc.hashCode());
  31:	                        Socket com = acc.accept();
  32:	                        tcp_peeraddr_print( com );
  33:	                        Thread th = new Thread( new EchoServerWorker(com) );
  34:	                        th.start();
  35:	                }
  36:	        }

 $ diff -c  EchoServerSingle.java EchoServer.java
 *** EchoServerSingle.java	2019-07-22 20:48:30.000000000 +0900 --- EchoServer.java	2019-07-27 14:57:38.000000000 +0900 ***************
 *** 1,26 ****
   /*
 !   EchoServerSingle.java -- 文字列を送受信するサーバ(TCP/IP, Java版, スレッドなし)
 !   ~yas/syspro/ipc/EchoServerSingle.java
 !   Created on 2004/05/09 20:00:24
   */

   import java.net.*;
   import java.io.*;

 ! class EchoServerSingle
   {
	 public static void main(String argv[]) throws IOException
	 {
		 if( argv.length != 1 )
		 {
 ! 			stderr.printf("Usage: %% java EchoServerSingle port\n");
			 System.exit( -1 );
		 }
		 int portno = Integer.parseInt( argv[0] );
 ! 		echo_server_single( portno );
	 }

 ! 	public static void echo_server_single( int portno ) throws IOException
	 {
		 ServerSocket acc = new ServerSocket( portno );
		 print_my_host_port( portno );
 --- 1,26 ----
   /*
 !   EchoServer.java -- 文字列を送受信するサーバ(TCP/IP, Java版)
 !   ~yas/syspro/ipc/EchoServer.java
 !   Created on 2004/02/14 16:22:13
   */

   import java.net.*;
   import java.io.*;

 ! class EchoServer
   {
	 public static void main(String argv[]) throws IOException
	 {
		 if( argv.length != 1 )
		 {
 ! 			stderr.printf("Usage: %% java EchoServer port\n");
			 System.exit( -1 );
		 }
		 int portno = Integer.parseInt( argv[0] );
 ! 		echo_server( portno );
	 }

 ! 	public static void echo_server( int portno ) throws IOException
	 {
		 ServerSocket acc = new ServerSocket( portno );
		 print_my_host_port( portno );
 ***************
 *** 30,37 ****
				       acc.hashCode();
			 Socket com = acc.accept();
			 tcp_peeraddr_print( com );
 ! 			EchoServerWorker esw = new EchoServerWorker(com);
 ! 			esw.run();
		 }
	 }
	 public static void print_my_host_port( int portno )
 --- 30,37 ----
				       acc.hashCode();
			 Socket com = acc.accept();
			 tcp_peeraddr_print( com );
 ! 			Thread th = new Thread( new EchoServerWorker(com) );
 ! 			th.start();
		 }
	 }
	 public static void print_my_host_port( int portno )

))

実行例

$ cp ~yas/syspro/ipc/EchoServer{,Worker}.java . 
$ ls *java 
EchoServer.java         EchoServerWorker.java
$ javac EchoServer.java EchoServerWorker.java 
$ ls *class 
EchoServer.class        EchoServerWorker.class
$ java  EchoServer 1231 
run telnet aloe30.local 1231
accepting incoming connections (hash== 1173230247) ...
connection (hash== 856419764) from 2001:2f8:3a:1711:0:0:230:39:53148
accepting incoming connections (hash== 1173230247) ...
received (com hash==856419764) 5 characters, [012
]
connection (hash== 621009875) from 2001:2f8:3a:1711:0:0:230:40:63522
accepting incoming connections (hash== 1173230247) ...
received (com hash==621009875) 5 characters, [abc
]
received (com hash==621009875) 5 characters, [def
]
received (com hash==856419764) 5 characters, [345
]
connection (com hash==856419764) closed.
connection (com hash==621009875) closed.
^C
$ 

$ telnet aloe30 1231 
Trying 2001:2f8:3a:1711::230:30...
Connected to aloe30.
Escape character is '^]'.
012
012
345
345
^]
telnet> ^D
Connection closed.
$ 

$ telnet aloe30 1231 
Trying 2001:2f8:3a:1711::230:30...
Connected to aloe30.
Escape character is '^]'.
abc
abc
def
def
^]
telnet> ^D
Connection closed.
$ 

スレッドの切り離し

    Thread th = new Thread( new EchoServerWorker(com) );
    th.setDaemon(true);
    th.start();