关注:CodingTechWork
引言
在项目开发中,有一个程序是专门给服务下发tcp端口占用的,但是tcp端口有时候会被其他服务给占用,此时端口就会冲突。本文提供一个工具类进行端口占用判断并返回可用端口。
代码
工具类
@Slf4j
public class SocketPortUtil {
public static int getNextAvailablePort(int fromPort) throws IOException {
ServerSocket serverSocket = null;
try {
//构建ServerSocket
serverSocket = new ServerSocket(fromPort);
return serverSocket.getLocalPort();
} catch (IOException e) {
// port被占用
log.info("port={} is not avaiable.", fromPort);
} finally {
if (serverSocket != null) {
serverSocket.close();
}
}
//递归查找下一个可用port
return getNextAvailablePort(fromPort + 1);
}
public static void main(String[] args) throws IOException {
int port = SocketPortUtil.getNextAvailablePort(64661);
System.out.println("next available port is: " + port);
}
}
测试
通过netstat
查找当前服务器被占用的tcp端口,如查看到64661端口被占用,运行上述main函数。测试结果如下:
11:19:06.721 [main] INFO com.test.selfcoding.utils.SocketPortUtil - port=64661 is not avaiable.
next available port is: 64662
Process finished with exit code 0