问题
In my application I create a ServerSocket instance with some port. After I am finished, I close the socket, but when I try to make a new ServerSocket on the same port, it throws:
"java.net.BindException: Address already in use"
If I create the ServerSocket with a different port, then it works.
ServerSocket.isClosed also returns true
What is the problem?
public void run() {
try {
BufferedInputStream bufferedinputstream = new BufferedInputStream(
new FileInputStream(fileReq));
BufferedOutputStream outStream = new BufferedOutputStream(
cs.getOutputStream());
byte buffer[] = new byte[1024];
int read;
System.out.println(cs);
while ((read = bufferedinputstream.read(buffer)) != -1)
{
outStream.write(buffer, 0, read);
outStream.flush();
}
System.out.println("File transfered");
outStream.close();
bufferedinputstream.close();
try {
this.finalize();
} catch (Throwable e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (Exception e) {
System.out.println("Exce....");
System.out.println(e.getMessage());
}
finally
{
if ( cs != null)
try {
int usedPort=cs.getLocalPort();
System.out.println("Closing "+cs);
cs.close();
System.out.println(cs+" Closed");
System.out.println("asd"+cs.isClosed());
portManager.getInstance().mp.put(usedPort,true);
} catch (IOException e) {
System.err.println("in sendToClient can't close sockt");
System.err.println(e.getMessage());
}
}
回答1:
Have you tried calling setReuseAddress(true) on the server socket? It's normal for the TCP state machine to enter TIME_WAIT state. For detailed explanation look here.
回答2:
It is because there is a cooldown period implemented on some O.S. If you wait a little (a couple of minutes for example), then you should be able to access the port again.
That being said, it is not a good idea to open and close serversockets on a port. It is better to open it and keep it open as long as necessary. Then close it when you are done. Don't open/close/open/close/open/close...
回答3:
Just close the socket when done. It automatically shuts down the port it is listening on. Never keep open the socket (port) when you are done.
回答4:
This means that the server is already open you need a check for user input or client input that says close the server like
while( bufferedinputstream != "quit" )
try{
...
}
Once you have the server open its just open until something closes it.
来源：https://stackoverflow.com/questions/6147481/how-to-close-port-after-using-server-sockets