Fixing Java.Net.Bindexception: Cannot Assign Requested Address: Jvm_Bind Inwards Tomcat, Jetty

Some of the most dreaded fault inwards Java based customer server based application is networking related error, e.g. java.net.BindException: Cannot assign requested address: JVM_Bind. I get got faced this issue, spell working alongside spider web servers similar Tomcat, Jetty, together with Weblogic before, exactly yesterday it came again, when ane of my colleague faced this termination inwards Windows. As presently every bit Java programmers sees java.net.BindException, they come upwards to decision that it's termination alongside two procedure listening on same port, together with ofttimes mistook it for Java.net.BindException: Address already inwards use: JVM_Bind:8080, which is slightly dissimilar than this.

If you lot hold back Java documentation for java.net.BindExcpetion, you lot volition uncovering this "Signals that an fault occurred spell attempting to bind a socket to a local address together with port. Typically, the port is inwards use, or the requested local address could non hold out assigned."

It's the second part, which is to a greater extent than interesting inwards illustration of java.net.BindException: Cannot assign requested address: JVM_Bind.

When you lot kickoff a web server or application server, which typically psyche on a port e.g. Tomcat or Jetty listens on 8080 together with 8084 for HTTP and HTTPS traffic, they bind a socket to a local address together with port. If you lot hand them hostname e.g. localhost or devhost, thus they used /etc/host inwards both Windows together with Linux to resolve domain advert into IP address, if this mapping is wrong than you lot volition teach java.net.BindException: Cannot assign requested address: JVM_Bind.

This host to IP address mapping file tin hold out flora at C:\Windows\System32\Drivers\etc\hosts, where C:\Windows is  where you lot get got installed windows operating system. If you lot hold back at this file, you lot volition come across it contains IP address together with hostname every bit shown below :

#127.0.0.1 localhost 192.168.52.1 localhost

If this mapping is changed together with localhost cannot hold out resolve to 192.168.52.1 thus you lot volition teach java.net.BindException: Cannot assign requested address: JVM_Bind. You tin testify past times next computer program to reproduce this issue, remember, you lot require admin rights to change /etc/host settings inwards Windows.

import java.io.IOException; import java.net.ServerSocket;  public class ServerSocketTesting {      public static void main(String args[]) throws IOException {          ServerSocket server = new ServerSocket(8080);         System.out.println("Server is started, listening connections on port :8080 ");         server.accept();     } }

If your /etc/host mapping is wrong than you lot volition come across something like

Exception inwards thread "main" java.net.BindException: Cannot assign requested address: JVM_Bind     at java.net.PlainSocketImpl.socketBind(Native Method)     at java.net.PlainSocketImpl.bind(PlainSocketImpl.java:383)     at java.net.ServerSocket.bind(ServerSocket.java:328)     at java.net.ServerSocket.(ServerSocket.java:194)     at java.net.ServerSocket.(ServerSocket.java:106)

Just, right the mapping, or add together 127.0.0.1 against localhost to resolve this issue.  That's all near how to laid java.net.BindException: Cannot assign requested address: JVM_Bind fault in Java based customer server application e.g. Minecraft, a pop game inwards Java, which also communicate alongside server together with other machines using TCP together with sockets. It could  also hold out locomote on when you lot are using spider web together with application server similar Tomcat, Jetty or Weblogic as well. Next time, instead of thinking that 2 procedure is listening on same port, also intend near hostname to IP address resolution termination together with verify contents of /etc/host file inwards both windows together with Linux. Let me know if you lot are facing this termination together with non able to resolve, pasting fault message together with what you lot are trying to compass volition manage to solve your fault speedily together with accurately.

How to resolve java.net.BindException: Cannot assign requested address: JVM_Bind inwards Tomcat

If you lot are getting this termination inwards Tomcat spider web server than opened upwards your server.xml, which contains host together with port information for Tomcat connectors. You tin uncovering server.xml inwards place (Windows OS) C:\Program Files\Apache Software Foundation\Apache Tomcat 7.0.41\conf\server.xml. Now hold back for your connector, if you lot are using default settings thus your connector volition hold back similar this :

 <Connector port="8080" protocol="HTTP/1.1"                connectionTimeout="20000"                redirectPort="8443" />

exactly if you lot get got modified it to include address="TestServer", thus hold back for TestServer mapping inwards /etc/hosts file. Try ping alongside the IP address together with come across if it upwards or not, you lot volition uncovering that it's incorrect. Just update alongside right IP together with restart Tomcat.

Similarly, you lot tin resolve java.net.BindException: Cannot assign requested address: JVM_Bind inwards Jetty or whatever other spider web server. Key affair is non to confuse this fault alongside address already inwards operate error.

All the best together with allow me know if you lot expression upwards similar issues.

Further Reading
The Complete Java MasterClass
Java Network Programming, (4th Addition) past times Harold, Elliotte Rusty
TCP/IP together with Networking Fundamentals for information technology Pros