Java socket programming example

I. Client

Package net. sockettest; import Java. io. bufferedreader; import Java. io. ioexception; import Java. io. inputstreamreader; import Java. io. outputstreamwriter; import Java. io. printwriter; import Java. io. reader; import Java. io. writer; import java.net. socket; import java.net. unknownhostexception; import Java. util. random; import Java. util. concurrent. executorservice; import Java. util. concurrent. executors; public class multithreadclient_jiaohu {public static void main (string [] ARGs) throws interruptedexception {int numtasks = 2120; executorservice exec = executors. newcachedthreadpool (); For (INT I = 0; I <numtasks; I ++) {thread. sleep (5l); exec.exe cute (createtask (I) ;}// define a simple task Private Static runnable createtask (final int taskid) {return New runnable () {private Socket socket = NULL; private int Port = 8821; Public void run () {socket clinet = NULL; int task_id = taskid; try {clinet = new socket ("192.168.252.155 ", port);} catch (unknownhostexception e) {// todo auto-generated catch blocke. printstacktrace ();} catch (ioexception e) {// todo auto-generated catch blocke. printstacktrace ();} reader = NULL; try {reader = new inputstreamreader (clinet. getinputstream ();} catch (ioexception e) {// todo auto-generated catch blocke. printstacktrace ();} bufferedreader clinetin = new bufferedreader (Reader); writer = NULL; try {writer = new outputstreamwriter (clinet. getoutputstream ();} catch (ioexception e) {// todo auto-generated catch blocke. printstacktrace ();} printwriter clientout = new printwriter (writer); int I = 0; while (true) {I ++; try {int ran = new random (). nextint (20*60) + 1; thread. sleep (Ran * 1000l);} catch (interruptedexception e) {// todo auto-generated catch blocke. printstacktrace ();} string STR = "Thread No.:" + task_id; clientout. println (STR); clientout. flush (); string newstr = NULL; try {newstr = clinetin. readline ();} catch (ioexception e) {// todo auto-generated catch blocke. printstacktrace ();} system. out. println ("--:" + newstr); if (I> = 100000) break;} Try {clinetin. close ();} catch (ioexception e) {// todo auto-generated catch blocke. printstacktrace ();} clientout. close (); system. out. println ("=== sending end = ");}};}}

Ii. Server

 

Package net. sockettest; import Java. io. bufferedreader; import Java. io. ioexception; import Java. io. inputstream; import Java. io. inputstreamreader; import Java. io. outputstream; import Java. io. printwriter; import java.net. *; import Java. util. concurrent. *; public class socketserver {private int Port = 8821; private serversocket; private executorservice; // thread pool private final int pool_siz E = 2200; // the size of a single CPU thread pool is also the maximum number of connections; otherwise, the number of connections exceeding this limit cannot be connected to private int COUNT = 0; Public socketserver () throws ioexception {serversocket = new serversocket (port); // The availableprocessor () method of runtime returns the number of CPUs of the current system. executorservice = executors. newfixedthreadpool (runtime. getruntime (). availableprocessors () * pool_size); system. out. println ("START socket server at Port:" + port);} public void start () {While (true) {Socket socket = nu Ll; try {// receive the customer connection. As long as the customer connects, accept () is triggered, and the connection socket = serversocket is established. accept (); count ++; system. out. println ("" + count); executorservice.exe cute (new handler (socket);} catch (exception e) {e. printstacktrace () ;}} public static void main (string [] ARGs) throws ioexception {New socketserver (). start () ;}} class handler implements runnable {private Socket socket; Public handler (Socket socket) {This. Socket = socket;} 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 void run () {try {system. out. println ("New Co Nnection accepted "+ 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 (MSG) ;}} catch (ioexception e) {e. printstacktrace ();} finally {try {If (socket! = NULL) socket. Close () ;}catch (ioexception e) {e. printstacktrace ();}}}}