java - Writing messages to client socket using DataOutputStream to Server Socket only sent after closing the Client Socket why? -

i had socket-client programming in java . using dataoutputstream send messages server socket . writed messages on dataoutputstream not sent serversocket . think it's due not flushing after sent message . no use . if terminate class execution receive messages serversocket .

my code :

public class loggingclient {   linkedblockingqueue<byte[]> messages = new linkedblockingqueue<byte[]>();  public static loggingclient clientobj;  /*  * waiting 2 seconds connecting centralized log server . if it's not reachable writing log's in local machine  * log's collected on eclipse restart.  */ public static final int socket_timeout = 2000; /**  * server log server running.  */ public static final  string server = "bharathi"; /**  * port log server running.  */ public static final int port = 10000;  /**  * client socket used connect server .  */ socket client = null;  public static logger logger = logger.getlogger(loggingclient.class.getname());   /**  * used write given logs client output stream.  */ dataoutputstream out = null;  public boolean isconnected = false;  /**  * used preventing instaniate loggingclient without calling getinstance method.  */ private loggingclient(){  }  /**  * clear's socket , initialize new socket .  */ public void init(){ try{     clear();     client = new socket();         client.settcpnodelay(true);     client.connect(new inetsocketaddress(server,port),socket_timeout); //trying make connection within 2 seconds.     out = new dataoutputstream(client.getoutputstream());     isconnected = true; }catch(exception e){     isconnected = false; } }  public static loggingclient getinstance(){ if(clientobj == null){     clientobj = new loggingclient(); } return clientobj; }  public void clear(){ try{     if(out != null){     out.close(); //if call close method invokes flush , closes dataoutputstream.     }      if(client != null){     client.close();     } }catch(exception e){     logger.log(level.info,"error while closing connection , reason {0}",e); }finally{     try{     client.close();     out.close();     }catch(exception e){      }     isconnected = false; } }   /**  * adding message queue . scheduled thread logs , push central logging server.  * @param message  */ public synchronized void write(byte[] message){ if(!isconnected){ //has connection.     init(); } messages.add(message); //adding message queue . background thread collect log message , sent central log server. }  /**  * sending logs central log server . if it's not reachable write local machine.  * @param message  */ public void sendlog(byte[] message){ try {     out.write(message);     out.flush(); } catch (exception e) {     writeinlocalmachine(localloggingpath, message); //in case of failure writing logs in local machine . sync logs when restart of eclipse. } }  /**  * writing log's machine log synced on plugin startup.  * @param file - file path.  * @param message - message  log.  */ public static void writeinlocalmachine(string file, byte[] message) { fileoutputstream filewriter = null; file f = new file(file); try {     if(!f.exists()){     f.createnewfile();     }     filewriter = new fileoutputstream(file, true);     filewriter.write(message);     filewriter.flush(); } catch (exception e) {    logger.log(         level.warning,         "this may due given file not found in system , reason {0}",         e); } {     try{     filewriter.close();     }catch(exception e){      } } }  /**  * @return - received message queue . returns null if it's empty.  */ public byte[] getmessage(){ return messages.poll(); //returns head element , deletes it. } 

}

testing java class sending messages server socket .

public class logtest implements runnable {  public static final string line_separator = system.getproperty("line.separator");   @override public void run() { while(true){     try{         loggingclient client = loggingclient.getinstance();         byte[] message = client.getmessage();         if(message != null){             client.sendlog(message);         }     }catch(exception e){      } } }  public static void startsending(){ for(int i=0;i<10000;i++){     string msg = "msg number" + i+line_separator;     loggingclient.getinstance().write(msg.getbytes()); } }  public static void main(string args[]){     loggingclient c = loggingclient.getinstance();     system.out.println("start time " + system.currenttimemillis());     thread t = new thread(new logtest(),"log messager");     t.start();     startsending();     system.out.println("end time " + system.currenttimemillis()); } 

sent messages stored in file .

ouput :

start time 1340815857896 end time 1340815858063 

finished putting messages queue . infinite while loop take care of sending logs server socket .

content stored in file 0 bytes why ? . if stop running class receive sent messages why?

you have posted code, 99 times out of 100 in these cases see data after stream / program has closed problem never flushing data after written