Address already in use on second Run of GWT project

Question

I have created First Sample GWT project. I have not customized any old configurations. I run the project first time, it was run sucessfully.

I stopped server and started by running the project. But Now, I get below error

[WARN] Server class 'org.eclipse.jetty.servlet.listener.ELContextCleaner' could not be found in the web app, but was found on the system classpath
   [WARN] Adding classpath entry 'file:/C:/dev/gwt-2.6.0/gwt-dev.jar' to the web app classpath for this session
   For additional info see: file:/C:/dev/gwt-2.6.0/doc/helpInfo/webAppClassPath.html
Starting Jetty on port 8888
   [WARN] FAILED SelectChannelConnector@127.0.0.1:8888: java.net.BindException: Address already in use: bind
java.net.BindException: Address already in use: bind
    at sun.nio.ch.Net.bind0(Native Method)
    at sun.nio.ch.Net.bind(Net.java:344)
    at sun.nio.ch.Net.bind(Net.java:336)
    at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:199)
    at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
    at org.eclipse.jetty.server.nio.SelectChannelConnector.open(SelectChannelConnector.java:187)
    at org.eclipse.jetty.server.AbstractConnector.doStart(AbstractConnector.java:316)
    at org.eclipse.jetty.server.nio.SelectChannelConnector.doStart(SelectChannelConnector.java:265)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
    at org.eclipse.jetty.server.Server.doStart(Server.java:293)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
    at com.google.gwt.dev.shell.jetty.JettyLauncher.start(JettyLauncher.java:717)
    at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:522)
    at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1104)
    at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:844)
    at com.google.gwt.dev.DevMode.main(DevMode.java:322)
   [WARN] FAILED org.eclipse.jetty.server.Server@1c6f846: java.net.BindException: Address already in use: bind
java.net.BindException: Address already in use: bind
    at sun.nio.ch.Net.bind0(Native Method)
    at sun.nio.ch.Net.bind(Net.java:344)
    at sun.nio.ch.Net.bind(Net.java:336)
    at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:199)
    at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
    at org.eclipse.jetty.server.nio.SelectChannelConnector.open(SelectChannelConnector.java:187)
    at org.eclipse.jetty.server.AbstractConnector.doStart(AbstractConnector.java:316)
    at org.eclipse.jetty.server.nio.SelectChannelConnector.doStart(SelectChannelConnector.java:265)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
    at org.eclipse.jetty.server.Server.doStart(Server.java:293)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
    at com.google.gwt.dev.shell.jetty.JettyLauncher.start(JettyLauncher.java:717)
    at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:522)
    at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1104)
    at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:844)
    at com.google.gwt.dev.DevMode.main(DevMode.java:322)
[ERROR] shell failed in doStartupServer method
Port 127.0.0.1:8888 is already is use; you probably still have another session active

It says port is already in Use. Can anyone tell where it is being used? Or is there any way to stop the usage of this port?

I used this online help to create gwt project.

Answer 1

Try to use unused port on each run.

On second run its also using same port no 8888 as shown in below snapshot. If first run is not stopped then it will result in error as mentioned by you.

Check automatically select unused port checkbox

Here is the settings

Go to Development mode and stop the already running server as shown below

If still its not working then close the Eclipse and restart.