String HOST = "myServer";
  int PORT = 1234;
  int NUM_OF_CONNECTION = 1000;

  InetAddress addr = InetAddress.getByName(HOST);

  Socket socket = null;

  for(int i=0; i<NUM_OF_CONNECTION; i++){

      try{
        socket = new Socket(addr, PORT);
      }catch(IOException e){
        e.printStackTrace();
        System.exit(-1);
      }

      doSomethingWithThisConnection(socket);
      
      try{
        socket.close();
      }catch(IOException e){
        e.printStackTrace();
        System.exit(-1);
      }
  }

java.net.BindException: Address already in use: connect
	at java.net.PlainSocketImpl.socketConnect(Native Method)
	at java.net.PlainSocketImpl.doConnect(Unknown Source)
	at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
	at java.net.PlainSocketImpl.connect(Unknown Source)
	at java.net.SocksSocketImpl.connect(Unknown Source)
	at java.net.Socket.connect(Unknown Source)
	at java.net.Socket.connect(Unknown Source)
	at java.net.Socket.<init>(Unknown Source)
	at java.net.Socket.<init>(Unknown Source)

[JAVA DOC]:

setReuseAddress(boolean on) throws SocketException

Enable/disable the SO_REUSEADDR socket option. 

When a TCP connection is closed the connection may remain in a timeout state 
for a period of time after the connection is closed (typically known as the
TIME_WAIT state or 2MSL wait state). For applications using a well known socket
address or port it may not be possible to bind a socket to the required
SocketAddress if there is a connection in the timeout state involving the socket
address or port. 

Enabling SO_REUSEADDR prior to binding the socket using bind(SocketAddress) 
allows the socket to be bound even though a previous connection is in a timeout state.