java编程： 查看端口是否已使用，出现问题

[D20152107]

源代码：
package getip;

import java.net.*;
import java.io.*;



public class CheckSocket {

public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
Socket Skt;
String host = "localhost";
if(args.length > 0) {
host = args[0];
}
for (int i = 0; i < 1024; i++) {
try {
System.out.println("查看"+ i);
Skt = new Socket(host, i);
System.out.println("端口 " + i + " 已被使用");
}
catch(UnknownHostException e) {
System.out.println("Exception occured" + e);
}
}

}

}


查看0
Exception in thread "main" java.net.ConnectException: connect: Address is invalid on local machine, or port is not valid on remote machine
at java.base/java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.base/java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.base/java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.base/java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.base/java.net.PlainSocketImpl.connect(Unknown Source)
at java.base/java.net.SocksSocketImpl.connect(Unknown Source)
at java.base/java.net.Socket.connect(Unknown Source)
at java.base/java.net.Socket.connect(Unknown Source)
at java.base/java.net.Socket.<init>(Unknown Source)
at java.base/java.net.Socket.<init>(Unknown Source)
at getip.CheckSocket.main(CheckSocket.java:20)

求教大佬，这是什么问题，如何解决，谢谢您！

[qq_39936465]

io异常需要处理

public static void main(String args[]) {
		Socket skt;
		String host="localhost";
		if(args.length>0) {
			host=args[0];
		}
		for(int i=0;i<50;i++) {
			try {
				System.out.println("查看"+i);
				skt = new Socket(host, i);
				System.out.println("端口"+i+"已被使用");
			} catch (UnknownHostException e) {
				// TODO Auto-generated catch block
				System.out.println(e);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				System.out.println(e);
			}
		}
	}