java - 未报告的异常 UnknownHostException；必须被抓住或宣布被扔掉

Question

我有一个下面给出的代码。但是，当我尝试编译代码时，出现以下错误。

MyClient.java:12: error: unreported exception UnknownHostException; must be caught or declared to be thrown
    InetAddress address = InetAddress.getByName("localhost");

我在代码中发现了上述异常。我不知道为什么会这样。？

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.ClassNotFoundException;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;

public class MyClient {    
    public static void main(String[] args) {
        InetAddress address = InetAddress.getByName("localhost");

        int count = 0;
        try {
            /*
             * Create a connection to the server socket on the server application
             */

            Socket socket = new Socket(address, 9090);

            /*
             * Read and display the response message sent by server application
             */

            ObjectInputStream ois = new ObjectInputStream(socket.getInputStream());
            System.out.println("Created client socket and Input Stream Reader");
            while (true) {
                if (count < 1000) {
                    String message = (String) ois.readObject();
                    System.out.println("OFMessage: " + message);
                    count++;
                } else {
                    break;
                }
            }

            ois.close();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Answer 1

InetAddress address = InetAddress.getByName("localhost");

这个语句在外面try{}，把它放在 try 块中，被你的 catch 块有效地捕获