Java:无法初始化InetAddress

Question

由于某种原因，我似乎无法初始化InetAddress对象，我查看了文档，它与我使用它的方式完全相同

 InetAddress firstMachineAddress = InetAddress.getByName("129.26.70.95");
 InetAddress secondMachineAddress = InetAddress.getByName("129.26.70.108");

Eclipse说：

Default constructor cannot handle exception type UnknownHostException thrown by implicit super constructor. Must define an explicit constructor

到底怎么了

Answer 1

inetAddress对象会抛出一个异常，因此您需要围绕它包装一个try catch，或者让您的方法也抛出一个异常。此外，我相信你得到了错误，因为有一个异常返回，你没有处理。getByName（）方法使用www.google等网址名称的字符串参数。com或www.amazon。com等等

try{
        InetAddress Address = InetAddress.getByName("www.google.com"); 
        System.out.println(Address);
    }catch(UnknownHostException e){
        e.printStackTrace();
    }

这显示了www.google。com/64.233.177.147

Answer 2

您的代码似乎位于一个类的构造函数中，该构造函数由另一个类扩展，如下所示：

import java.net.*;

class SuperclassWithUnknownHostException {
    public SuperclassWithUnknownHostException() throws UnknownHostException {
        InetAddress firstMachineAddress = InetAddress.getByName("129.26.70.95");
        InetAddress secondMachineAddress = InetAddress.getByName("129.26.70.108");
    }
}

class SubclassCannotHandleException extends SuperclassWithUnknownHostException {

}

您需要向引发异常的子类添加默认构造函数：

class SubclassCannotHandleException extends SuperclassWithUnknownHostException {
    public SubclassCannotHandleException() throws UnknownHostException {

    }
}