Java中的 URL getHost() 方法及示例

getHost()函数是 URL 类的一部分。函数getHost() 返回指定 URL 的主机。 URL 的 Host 部分是 URL 的主机名。主机的格式符合 RFC 2732。

函数签名

public String getHost()

句法

url.getHost()

参数：此函数不需要任何参数

返回类型：函数返回字符串类型

下面的程序说明了 getHost()函数的使用：

示例 1：

// Java program to show the use
// of the function getHost()
  
import java.net.*;
  
class GFG {
    public static void main(String args[])
    {
        // url  object
        URL url = null;
  
        try {
  
            // create a URL
            url
                = new URL("https:// www.geeksforgeeks.org");
  
            // get the Host
            String Host = url.getHost();
  
            // display the URL
            System.out.println("URL = " + url);
  
            // display the Host
            System.out.println("Host = " + Host);
        }
  
        // if any error occurs
        catch (Exception e) {
  
            // display the error
            System.out.println(e);
        }
    }
}

输出：

URL = https:// www.geeksforgeeks.org
Host =  www.geeksforgeeks.org

示例 2：

// Java program to show the
// use of the function getHost()
  
import java.net.*;
  
class GFG {
    public static void main(String args[])
    {
        // url  object
        URL url = null;
  
        try {
            // create a URL
            url
                = new URL(
                    "https:// www.geeksforgeeks.org:80/url-samefile-method-in-java-with-examples/");
  
            // get the Authority
            String authority
                = url.getAuthority();
  
            // get the Host
            String host = url.getHost();
  
            // display the URL
            System.out.println("URL = " + url);
  
            // display the Host
            System.out.println("Authority = "
                               + authority);
  
            // display the Host
            System.out.println("Host = " + host);
        }
        // if any error occurs
        catch (Exception e) {
  
            // display the error
            System.out.println(e);
        }
    }
}

输出：

URL = https:// www.geeksforgeeks.org:80/url-samefile-method-in-java-with-examples/
Authority =  www.geeksforgeeks.org:80
Host =  www.geeksforgeeks.org

示例 3：如果我们创建一个没有主机名的 URL 并使用 getHost()函数请求主机，则该函数返回空白字符串。

// Java program to show the
// use of the function getHost()
  
import java.net.*;
  
class GFG {
    public static void main(String args[])
    {
        // url  object
        URL url = null;
  
        try {
            // create a URL
            url = new URL("https://");
  
            // get the Host
            String Host = url.getHost();
  
            // display the URL
            System.out.println("URL = " + url);
  
            // display the Host
            System.out.println("Host = " + Host);
        }
  
        // if any error occurs
        catch (Exception e) {
  
            // display the error
            System.out.println(e);
        }
    }
}

输出：

URL = https:
Host =