使用DataOutputStream将消息写入客户端套接字仅在关闭Client Socket后发送到服务器套接字为什么？
我用Java编写了一个Socket-Client编程。 我正在使用DataOutputStream将消息发送到服务器套接字。 有时，DataOutputstream上的写入消息未发送到ServerSocket。 我认为这是因为我发送消息后没有冲洗。 我这样做但没用。 如果我终止类执行，那么只有我从ServerSocket接收消息。
我的代码：
public class LoggingClient { LinkedBlockingQueue messages = new LinkedBlockingQueue(); public static LoggingClient clientObj; /* * waiting 2 seconds for connecting centralized log server . If it's not reachable writing log's in local machine * this log's will be collected on eclipse restart. */ public static final int SOCKET_TIMEOUT = 2000; /** * Server which the log server is currently running. */ public static final String SERVER = "bharathi"; /** * Port which the log server is running. */ public static final int PORT = 10000; /** * Client socket used to connect the server . */ Socket client = null; public static Logger logger = Logger.getLogger(LoggingClient.class.getName()); /** * Used to write given logs into client output stream. */ DataOutputStream out = null; public boolean isConnected = false; /** * Used for preventing instaniate LoggingClient without calling getInstance method. */ private LoggingClient(){ } /** * Clear's the socket and initialize new socket . */ public void init(){ try{ clear(); client = new Socket(); client.setTcpNoDelay(true); client.connect(new InetSocketAddress(SERVER,PORT),SOCKET_TIMEOUT); //trying to make connection within two 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 we call close method it invokes flush and then closes the 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 this message into a queue . Scheduled thread will get this logs and push into central logging server. * @param message */ public synchronized void write(byte[] message){ if(!isConnected){ //has connection. init(); } messages.add(message); //adding message to this queue . Background thread will collect the log message and sent it to the central log server. } /** * Sending logs into central log server . If it's not reachable write into 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 this logs when restart of eclipse. } } /** * Writing log's into his machine this log will be synced on plugin startup. * @param file - File path. * @param message - Message to 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 be due to given file not found in system , reason {0}", e); } finally { try{ fileWriter.close(); }catch(Exception e){ } } } /** * @return - Recently received message from queue . Returns null if it's empty. */ public byte[] getMessage(){ return messages.poll(); //returns the head element and deletes it. } }
测试用于将消息发送到服务器套接字的java类。
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()); }
已发送的消息将存储在文件中。
输出：
START TIME 1340815857896 END TIME 1340815858063
完成将消息放入队列。 无限while循环将负责将日志发送到服务器套接字。
存储在文件中的内容是0字节为什么？ 。 如果我停止运行课程，我会收到发送消息的原因？
您发布了太多代码，但是在这些情况下，只有在流/程序关闭您的问题后才能看到数据的情况下，您已经发布了99次，但是在写入数据后您永远不会刷新数据