Java主線程不會喚醒ServerSocket接受

Question

我正在使用java創建一個簡單的Web代理應用程序。基本上，主要方法創建一個RequestReceiver對象，該對象具有監聽Web瀏覽器http請求的ServerSocket。一個新的Connection對象是從serverSocket.accept（）返回的套接字創建的，並被放入一個線程池中。

我遇到的問題是，並非所有的http GET請求似乎都被serverSocket拾取。例如，在我測試的一個網頁上，我可以看到代理服務器只收到了10個GET請求中的7個。這會導致網頁掛起並需要很長時間才能加載。什麼可能導致帶有serverSocket.accept（）函數的線程在創建新連接時不總是優先執行？

RequestReceiver.java

public class RequestReceiver { 
    public static final int LISTENING_PORT = 4000; 
    public static final int CONNECTION_THREAD_POOL_SIZE = 30; 

    private ServerSocket serverSocket; 
    private ThreadPoolExecutor connectionThreads; 

    public RequestReceiver() throws IOException{ 
     serverSocket = new ServerSocket(LISTENING_PORT); 
     connectionThreads = new ThreadPoolExecutor(CONNECTION_THREAD_POOL_SIZE, CONNECTION_THREAD_POOL_SIZE, 
       1000, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>()); 
    } 

    public void start(){ 
     try { 
      System.out.println("Current Pool Size: " + connectionThreads.getPoolSize() 
        + " Active threads: " + connectionThreads.getActiveCount()); 
      Connection conn = new Connection(serverSocket.accept()); 
      System.out.println("Created a new connection thread. Request from " + conn.clientSocketToString()); 
      connectionThreads.execute(conn); 
     } catch (IOException e) { 
      System.err.println("Exception occured when accepting a new connection."); 
      e.printStackTrace(); 
     } 
    } 
} 

Connection.java

public class Connection implements Runnable{ 

public static final int REPLY_CHUNK_SIZE = 32768; 
public static final int DEFAULT_WEB_SERVER_PORT = 80; 
public static final int SERVER_SOCKET_TIMEOUT = 0; // milliseconds 
public static final int CLIENT_SOCKET_TIMEOUT = 0; // milliseconds 

private Socket clientSocket, serverSocket; 
private InputStream clientIS, serverIS; 
private OutputStream clientOS, serverOS; 

public Connection(Socket clientSocket){ 
    this.clientSocket = clientSocket; 
    // set client socket timeout 
    try{ 
     clientSocket.setSoTimeout(CLIENT_SOCKET_TIMEOUT); 
    }catch(SocketException soe){ 
     soe.printStackTrace(); 
    } 
} 

@Override 
public void run() { 
    String connection = ""; 
    try{ 
     // setup client streams 
     clientIS = clientSocket.getInputStream(); 
     clientOS = clientSocket.getOutputStream(); 
     // get the request from the browser 
     String request = ""; 
     String hostname = ""; 
     String[] hostAndPort = new String[2]; 
     request = browserInputStreamToString(clientIS); 
     hostname = getHostName(request); 
     hostAndPort = hostname.split(":"); 
     connection = "Connection to: " + hostname + " from " + clientSocket.getInetAddress().getHostName() 
       + ":" + clientSocket.getPort() + " Request: " + request.split(System.getProperty("line.separator"))[0]; 
     System.out.println("OPENED>> " + connection); 
     // Attempt to create socket to server 
     serverSocket = new Socket(hostAndPort[0], (hostAndPort.length > 1 ? new Integer(hostAndPort[1]):DEFAULT_WEB_SERVER_PORT)); 
     // set timeout 
     serverSocket.setSoTimeout(SERVER_SOCKET_TIMEOUT); 
     // Set up server streams 
     serverIS = serverSocket.getInputStream(); 
     serverOS = serverSocket.getOutputStream(); 
     // send client request to server 
     serverOS.write(request.getBytes()); 
     serverOS.flush(); 
     // send server response to client in chunks 
     byte[] reply = new byte[REPLY_CHUNK_SIZE]; 
     int replyLength = serverIS.read(reply); 
     while(replyLength != -1){ 
      clientOS.write(reply, 0, replyLength); 
      clientOS.flush(); 
      replyLength = serverIS.read(reply); 
     } 
     // close sockets 
     clientSocket.close(); 
     serverSocket.close(); 
    }catch(Exception e){ 
     e.printStackTrace(); 
    } finally{ 
     try { 
      if(clientSocket != null){ 
       clientSocket.close(); 
      } 
      if(serverSocket != null){ 
       serverSocket.close(); 
      } 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    } 
    System.out.println("CLOSED>> " + connection); 
} 

編輯：從catch語句刪除return語句

Answer 1

當你說7出10，你的意思是你測試的10倍或幾次，並得到這個速度？我問，因爲默認隊列大小是50，所以如果你測試了很多，你可能會遇到隊列問題。如果你還沒有改變隊列大小..

其他的事情，也關於隊列大小。你有幾個回報和嘗試緩存。如果發生任何事情，您將無法完成您的連接關閉。所以當隊列滿時，你會得到超時，直到當前連接關閉。其他相關問題，資源泄漏。