Embedded Jetty with Maven example fails to restart: Address already in use

Question

When trying to repeatedly run the Embedded Jetty with Maven example in NetBeans, I unfortunately get the error:

cd /Users/afarber/src/JettyMavenHelloWorld; JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home "/Applications/NetBeans/NetBeans 8.1.app/Contents/Resources/NetBeans/java/maven/bin/mvn" "-Dexec.args=-classpath %classpath org.example.HelloWorld" -Dexec.executable=/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/bin/java org.codehaus.mojo:exec-maven-plugin:1.2.1:exec
Running NetBeans Compile On Save execution. Phase execution is skipped and output directories of dependency projects (with Compile on Save turned on) will be used instead of their jar artifacts.
Scanning for projects...

------------------------------------------------------------------------
Building Jetty HelloWorld 0.1-SNAPSHOT
------------------------------------------------------------------------

--- exec-maven-plugin:1.2.1:exec (default-cli) @ hello-world ---
2016-05-24 19:01:26.748:INFO:oejs.Server:main: jetty-9.0.2.v20130417
2016-05-24 19:01:26.817:WARN:oejuc.AbstractLifeCycle:main: FAILED ServerConnector@7591083d{HTTP/1.1}{0.0.0.0:8080}: java.net.BindException: Address already in use
java.net.BindException: Address already in use
    at sun.nio.ch.Net.bind0(Native Method)
    at sun.nio.ch.Net.bind(Net.java:437)
    at sun.nio.ch.Net.bind(Net.java:429)
    at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
    at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
    at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:227)
    at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)
    at org.eclipse.jetty.server.Server.doStart(Server.java:309)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)
    at org.example.HelloWorld.main(HelloWorld.java:29)
2016-05-24 19:01:26.818:WARN:oejuc.AbstractLifeCycle:main: FAILED org.eclipse.jetty.server.Server@77a567e1: java.net.BindException: Address already in use
java.net.BindException: Address already in use
    at sun.nio.ch.Net.bind0(Native Method)
    at sun.nio.ch.Net.bind(Net.java:437)
    at sun.nio.ch.Net.bind(Net.java:429)
    at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
    at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
    at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:227)
    at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)
    at org.eclipse.jetty.server.Server.doStart(Server.java:309)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)
    at org.example.HelloWorld.main(HelloWorld.java:29)
Exception in thread "main" java.net.BindException: Address already in use
    at sun.nio.ch.Net.bind0(Native Method)
    at sun.nio.ch.Net.bind(Net.java:437)
    at sun.nio.ch.Net.bind(Net.java:429)
    at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
    at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
    at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:227)
    at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)
    at org.eclipse.jetty.server.Server.doStart(Server.java:309)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)
    at org.example.HelloWorld.main(HelloWorld.java:29)

If the root cause for this is the SO_REUSEADDR limitation when binding listening sockets - then probably ServerSocket.setReuseAddress(true) would help.

But how and where to call it in the HelloWorld.java?

package org.example;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import java.io.IOException;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.server.handler.AbstractHandler;

public class HelloWorld extends AbstractHandler
{
    public void handle(String target,
                       Request baseRequest,
                       HttpServletRequest request,
                       HttpServletResponse response)
        throws IOException, ServletException
    {
        response.setContentType("text/html;charset=utf-8");
        response.setStatus(HttpServletResponse.SC_OK);
        baseRequest.setHandled(true);
        response.getWriter().println("<h1>Hello World</h1>");
    }

    public static void main(String[] args) throws Exception
    {
        Server server = new Server(8080);
        server.setHandler(new HelloWorld());
        server.start();
        server.join();
    }
}

I am using the following pom.xml:

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

  <modelVersion>4.0.0</modelVersion>
  <groupId>org.example</groupId>
  <artifactId>hello-world</artifactId>
  <version>0.1-SNAPSHOT</version>
  <packaging>jar</packaging>
  <name>Jetty HelloWorld</name>

  <properties>
      <jettyVersion>9.3.9.v20160517</jettyVersion>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.eclipse.jetty</groupId>
      <artifactId>jetty-server</artifactId>
      <version>${jettyVersion}</version>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>exec-maven-plugin</artifactId>
        <version>1.1</version>
        <executions>
          <execution><goals><goal>java</goal></goals></execution>
        </executions>
        <configuration>
          <mainClass>org.example.HelloWorld</mainClass>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

UPDATE:

Lars Gendner is correct and I do have HelloWorld processes still running at my Macbook:

# ps -ef | grep HelloWorld
  501   944     1   0  6:58pm ??         0:04.20 /Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/bin/java -classpath /Users/afarber/src/JettyMavenHelloWorld/target/classes:/Users/afarber/.m2/repository/org/eclipse/jetty/jetty-server/9.0.2.v20130417/jetty-server-9.0.2.v20130417.jar:/Users/afarber/.m2/repository/org/eclipse/jetty/orbit/javax.servlet/3.0.0.v201112011016/javax.servlet-3.0.0.v201112011016.jar:/Users/afarber/.m2/repository/org/eclipse/jetty/jetty-http/9.0.2.v20130417/jetty-http-9.0.2.v20130417.jar:/Users/afarber/.m2/repository/org/eclipse/jetty/jetty-util/9.0.2.v20130417/jetty-util-9.0.2.v20130417.jar:/Users/afarber/.m2/repository/org/eclipse/jetty/jetty-io/9.0.2.v20130417/jetty-io-9.0.2.v20130417.jar org.example.HelloWorld
  501   948     1   0  6:58pm ??         0:03.89 /Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/bin/java -classpath /Users/afarber/src/JettyMavenHelloWorld/target/classes:/Users/afarber/.m2/repository/org/eclipse/jetty/jetty-server/9.0.2.v20130417/jetty-server-9.0.2.v20130417.jar:/Users/afarber/.m2/repository/org/eclipse/jetty/orbit/javax.servlet/3.0.0.v201112011016/javax.servlet-3.0.0.v201112011016.jar:/Users/afarber/.m2/repository/org/eclipse/jetty/jetty-http/9.0.2.v20130417/jetty-http-9.0.2.v20130417.jar:/Users/afarber/.m2/repository/org/eclipse/jetty/jetty-util/9.0.2.v20130417/jetty-util-9.0.2.v20130417.jar:/Users/afarber/.m2/repository/org/eclipse/jetty/jetty-io/9.0.2.v20130417/jetty-io-9.0.2.v20130417.jar org.example.HelloWorld

And the port 8080 is in use:

# netstat -an | grep -w 8080
tcp46      0      0  *.8080                 *.*                    LISTEN

But of course I do not want to change port number again and again (and spawn more processes).

Instead (being NetBeans and Jetty newbie) I wonder how to properly stop embedded Jetty in NetBeans? (besides of awk /HelloWorld/ '{print $2}'| xargs kill workaround)

UPDATE 2:

Adding jetty-maven-plugin to the pom.xml and runningmvn jetty:run does start a web server at port 8080, but it only displays the red text:

Directory: /

Here is the full Maven output:

# mvn jetty:run
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building Jetty HelloWorld 0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] >>> jetty-maven-plugin:9.3.9.v20160517:run (default-cli) > test-compile @ hello-world >>>
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ hello-world ---
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory /Users/afarber/src/jetty-newbie/JettyMavenHelloWorld/src/main/resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ hello-world ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding UTF-8, i.e. build is platform dependent!
[INFO] Compiling 1 source file to /Users/afarber/src/jetty-newbie/JettyMavenHelloWorld/target/classes
[INFO] 
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ hello-world ---
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory /Users/afarber/src/jetty-newbie/JettyMavenHelloWorld/src/test/resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ hello-world ---
[INFO] No sources to compile
[INFO] 
[INFO] <<< jetty-maven-plugin:9.3.9.v20160517:run (default-cli) < test-compile @ hello-world <<<
[INFO] 
[INFO] --- jetty-maven-plugin:9.3.9.v20160517:run (default-cli) @ hello-world ---
[INFO] Configuring Jetty for project: Jetty HelloWorld
[INFO] webAppSourceDirectory not set. Trying src/main/webapp
[INFO] webAppSourceDirectory /Users/afarber/src/jetty-newbie/JettyMavenHelloWorld/src/main/webapp does not exist. Trying /Users/afarber/src/jetty-newbie/JettyMavenHelloWorld/target/webapp-tmp
[INFO] Reload Mechanic: automatic
[INFO] Classes = /Users/afarber/src/jetty-newbie/JettyMavenHelloWorld/target/classes
[INFO] Logging initialized @3610ms
[INFO] Context path = /
[INFO] Tmp directory = /Users/afarber/src/jetty-newbie/JettyMavenHelloWorld/target/tmp
[INFO] Web defaults = org/eclipse/jetty/webapp/webdefault.xml
[INFO] Web overrides =  none
[INFO] web.xml file = null
[INFO] Webapp directory = /Users/afarber/src/jetty-newbie/JettyMavenHelloWorld/target/webapp-tmp
[INFO] jetty-9.3.9.v20160517
[INFO] Started o.e.j.m.p.JettyWebAppContext@58a63629{/,file:///Users/afarber/src/jetty-newbie/JettyMavenHelloWorld/target/webapp-tmp/,AVAILABLE}{file:///Users/afarber/src/jetty-newbie/JettyMavenHelloWorld/target/webapp-tmp/}
[INFO] Started ServerConnector@75a118e6{HTTP/1.1,[http/1.1]}{0.0.0.0:8080}
[INFO] Started @4608ms
[INFO] Started Jetty Server
[INFO] Using Non-Native Java sun.nio.fs.PollingWatchService
[WARNING] Quiet Time is too low for non-native WatchService [sun.nio.fs.PollingWatchService]: 1000 < 5000 ms (defaulting to 5000 ms)

Are you using `jetty-maven-plugin` in your pom.xml? please post it in your question. — Lucky, May 25 '16 at 07:45
I have added the [pom.xml](https://github.com/afarber/jetty-newbie/blob/master/JettyMavenHelloWorld/pom.xml) to my question, I am not using jetty-maven-plugin yet — Alexander Farber, May 25 '16 at 07:48
This post has a more detailed answer for killing the processes. http://stackoverflow.com/questions/7082476/jetty-startup-fails-address-in-use — Semih Sezer, Jun 18 '16 at 04:13

score 1 · Answer 1 · answered May 24 '16 at 17:27

1

I am pretty sure that you already have a process running on port 8080. If you track down that process and end it (maybe you are trying to start Jetty twice instead of ending an already running Jetty instance properly?), your process should start just fine.

You can also try and use some other port instead of 8080 (e.g. 8090).

answered May 24 '16 at 17:27

Lars Gendner

1,816
2
14
24

Yes, you're correct - there are processes running... So my question (I have updated it) is: **how to stop embedded Jetty properly**, so that I can debug my handler again? – Alexander Farber May 24 '16 at 17:34
1

Easiest way is to kill the running processes (using "kill " or "kill -9 "). Or are you looking for some automated solution? – Lars Gendner May 24 '16 at 17:39
1

Then maybe http://stackoverflow.com/questions/14981435/how-do-i-stop-jetty could help? – Lars Gendner May 24 '16 at 17:53
Yes, `ps -ef | awk '/HelloWorld/ {print $2}' | xargs kill` would work, but I am looking for the Jetty command to stop the running embedded Jetty-server. Like `mvn jetty:stop` (which does not work for me either)... – Alexander Farber May 24 '16 at 20:24
What about the command mentioned in the link? "java -jar start.jar STOP.PORT= STOP.KEY=" – Lars Gendner May 25 '16 at 08:15

score 1 · Accepted Answer · answered May 25 '16 at 08:03

1

You should add jetty-maven-plugin to your pom and try stopping the server. The jetty stop goal looks for the plugin configuration. Please refer this jetty doc Jetty Stop goal

The stop goal stops a running instance of jetty. To use it, you need to configure the plugin with a special port number and key. That same port number and key will also be used by the other goals that start jetty.

Here's the plugin configuration for jetty-stop,

<plugin>
  <groupId>org.eclipse.jetty</groupId>
  <artifactId>jetty-maven-plugin</artifactId>
  <version>@project.version@</version>
  <configuration>
    <stopPort>9966</stopPort>
    <stopKey>foo</stopKey>
    <stopWait>10</stopWait>
  </configuration>
</plugin>

And after jetty is started, issue the following command,

mvn jetty:stopmvn jetty:stop

or simply try the

mvn jetty:stop

And mvn jetty:run command would start the server. For other goals/configurations please refer to Configuring Jetty Maven plugin

answered May 25 '16 at 08:03

Lucky

16,787
19
117
151

Thank you, but I have tried your suggestion both on Win 7 and Mac OSX and `mvn jetty:run` does start a web server now, but it only displays a red text `Directory: /` (please see the update 2 in my question) – Alexander Farber May 25 '16 at 16:11
1

@Alexander Yes your webapp started successfully and you should be able to access the site at `http://localhost:8080`. This will show the available contexts registered by jetty. The log show that you don't have webapp folder. And did the jetty stop goal work? – Lucky May 25 '16 at 16:46
Yes, but my handler `response.getWriter().println("
Hello World
");` is not called for some reason? – Alexander Farber May 25 '16 at 16:50
1

Do you have a servlet mapping in your web.xml for the HelloWorld servlet? You shuld add the servlet mapping request URL and servlet class in it for this to work. – Lucky May 25 '16 at 17:00
This post [Servlet Mapping using web.xml](http://stackoverflow.com/q/8198312/1793718) should help you for mapping your servlet handler methods with request urls. Or as suggested in the answer you can use [@WebServlet](http://docs.oracle.com/javaee/6/api/javax/servlet/annotation/WebServlet.html) since Servlet 3.0. – Lucky May 26 '16 at 06:48

Embedded Jetty with Maven example fails to restart: Address already in use

2 Answers2

Hello World