How do I fix Java net UnknownHostException?
To resolve:
- Do echo $HOSTNAME on your terminal.
- Whatever hostname it shows (lets say myHostName ), try to ping it : ping myHostName . If it returns ping: cannot resolve myHostName: Unknown host then add an entry into your /etc/hosts file.
- For that edit /etc/hosts file and add following: 127.0.0.1 myHostName.
What is InetAddress getLocalHost ()?
Java InetAddress getLocalHost() method The getLocalHost() method of Java InetAddress class returns the instance of InetAddress containing local host name and address. In this, firstly the host name is retrieved from the system, then that name is resolved into InetAddress.
What is Java net InetAddress?
The java. net. InetAddress class provides methods to get the IP address of any hostname. An IP address is represented by 32-bit or 128-bit unsigned number. InetAddress can handle both IPv4 and IPv6 addresses.
How do I find my hostname in InetAddress?
Example 1
- import java.net.InetAddress;
- import java.net.UnknownHostException;
- public class JavaInetAddressGetHostNameExample1 {
- public static void main(String[] args) {
- try {
- InetAddress id = InetAddress.getLocalHost();
- System.out.println( id.getHostName());
- } catch (UnknownHostException e) {
What causes Java net UnknownHostException?
UnknownHostException indicates that the IP address of a hostname could not be determined. It can happen because of a typo in the hostname: String hostname = “http://locaihost”; URL url = new URL(hostname); HttpURLConnection con = (HttpURLConnection) url.
What does UnknownHostException mean?
UnknownHostException is a common error message in Java applications. This error typically indicates that there was a DNS resolution failure. However, the message is generic, and it doesn’t describe the root cause of the issue.
What is InetAddress class discuss?
InetAddress class is Java’s encapsulation of an IP address. It is used by most of the other networking classes, including Socket , ServerSocket , URL , DatagramSocket , DatagramPacket , and more. public final class InetAddress extends Object implements Serializable.
What is an InetAddress?
The InetAddress is Java’s representation of an IP address. Instances of this class are used together with UDP DatagramSockets and normal Socket’s and ServerSocket’s.
What methods can you use to get the IP address and hostname from an InetAddress?
In Java, you can use InetAddress. getLocalHost() to get the Ip Address of the current Server running the Java app and InetAddress. getHostName() to get Hostname of the current Server name.
What are the reasons of getting UnknownHostException error even if all the settings are properly configured?
UnknownHostException typically occurs when one of the following is true. 1) TCP/IP is not started on the server. 2) The Fully Qualified Domain Name (FQDN), which consists of the hostName. domainName (i.e. server.ibm.com) listed in CFGTCP Option 12 is not being resolved to a valid IP address properly.
Does inetaddress getlocalhost ignore the resolv file?
It seems that InetAddress.getLocalHost () ignores the /etc/resolv.conf, but only looks at the /etc/hosts file (where I hadn’t specified anything besides localhost ). Adding the IP and hostname to this file solves the problem and the exception is gone. Another answer is almost correct and I got hint from above and my problem get resolved…Thanks.
What is the use of getlocalhost () method in Java?
The getLocalHost () method of Java InetAddress class returns the instance of InetAddress containing local host name and address. In this, firstly the host name is retrieved from the system, then that name is resolved into InetAddress. It returns the instance of the local host.
What does it return when it calls unknownhostexception?
It returns the instance of the local host. UnknownHostException: if the local host name could not be resolved into an instance.
How do I get the local host name in Java?
Java InetAddress getLocalHost () method The getLocalHost () method of Java InetAddress class returns the instance of InetAddress containing local host name and address. In this, firstly the host name is retrieved from the system, then that name is resolved into InetAddress.