我的代码

public class MainActivity {
    public static void main(String[] args) throws IOException {
        //1.创建客户端Socket，指定服务器地址和端口
        Socket socket = new Socket("***.***.**.*",8080);
        //2.获取输出流，向服务器端发送信息
        OutputStream os = socket.getOutputStream();//字节输出流
        PrintWriter pw = new PrintWriter(os);//将输出流包装为打印流
        //获取客户端的IP地址
        InetAddress address = InetAddress.getLocalHost();
        String ip = address.getHostAddress();
        System.out.println("本地ip：" + ip);
        System.out.println("本地端口:" + socket.getLocalPort());
        System.out.println("连接服务端ip:"+socket.getInetAddress());
        System.out.println("打印服务器端口:"+socket.getPort());
        System.out.println("本地地址:"+socket.getLocalAddress());
        System.out.println("本地端口:" + socket.getLocalPort());
        pw.write("客户端：~" + ip + "~ 接入服务器！！");
        pw.flush();
        System.out.println();
        socket.shutdownOutput();//关闭输出流
        socket.close();
    }
}

错误原因 ： Connection refused: connect。

Exception in thread "main" java.net.ConnectException: Connection refused: connect
	at java.net.DualStackPlainSocketImpl.connect0(Native Method)
	at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
	at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
	at java.net.Socket.connect(Socket.java:589)
	at java.net.Socket.connect(Socket.java:538)
	at java.net.Socket.<init>(Socket.java:434)
	at java.net.Socket.<init>(Socket.java:211)
	at cn.hyyj.project.gateway.socket.test1.MainActivity.main(MainActivity.java:11)

这是因为自己提供的IP和端口没有组合不正确。所以会报错。

解决方案：

我们可以使用【win】 + 【r】打开cmd窗口

输入：netstat -na 查看自己电脑的IP地址和端口

 ipconfig也可以看自己电脑和连接的IP地址