How do I write a simple Servlet for Jetty using Eclipse?
Solution 1
First, your web.xml is wrong.
The servlet-class element contains the fully qualified class name of the servlet.
from web.xml schema you used http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd at line 923. Hence, the content of servlet-class element at line 9 should be MyServlet
, not MyServlet.class
.
Second, use only one way to register a servlet, filter or listener to make it clear. If you prefer to use annotation to register them to a servlet container. You had better delete servlet and servlet-mapping element in web.xml. Otherwise, You had better delete annotations in java source. And if you want to use web.xml, you should update the schema version from 2.4 to 3.0
Finally, your second problem came from the Jetty WTP Eclipse plugin can be solved by trying this: jetty run error for websockets project
Solution 2
The way you are accessing the servet may be wrong.
If we observe the war you are deploying is MySite.war
and the url you are using is localhost:8080\MyServlet\Servlet
Try with localhost:8080\MySite\Servlet
Jonas
Passionated Software Developer interested in Distributed Systems
Updated on January 31, 2020Comments
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Jonas about 4 years
I downloaded Eclipse for Java EE and Jetty 8.1 and would like to implement a very simple Servlet.
Jetty works fine when I start it using
java -jar start.jar
.To develop the Servlet I did this:
In Eclipse, I choosed "New Dynamic Web Project".
I added
jetty\lib\servlet-api-3.0.jar
to the "Build Path" in Eclipse.-
In that project, "New Servlet", and a Servlet was generated and I added some code:
/** * Servlet implementation class MyServlet */ @WebServlet("/MyServlet") public class MyServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { PrintWriter out = response.getWriter(); out.println("<html><body><h1>My Servlet</h1></body></html>"); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub } }
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I created a file
web.xml
inWebContent\WEB-INF\web.xml
with this content:<?xml version="1.0" encoding="utf-8" ?> <web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4"> <servlet> <servlet-name>My Servlet</servlet-name> <servlet-class>MyServlet.class</servlet-class> </servlet> <servlet-mapping> <servlet-name>My Servlet</servlet-name> <url-pattern>/Servlet</url-pattern> </servlet-mapping>
I copied the compiled
.class
-files inbuild\classes
toWebContent\WEB-INF\classes
Now I choose to Export the project as a
.war
-file tojetty\webapps\MySite.war
.-
I start Jetty with
java -jar start.jar
and visitlocalhost:8080/MySite/Servlet
but now I get this message:Servlet Not Initialized javax.servlet.UnavailableException: Servlet Not Initialized at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:546) at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:485) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119) at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:483) at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:233) at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1065) at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:412) at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:192) at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:999) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117) at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:250) at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:149) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:111) at org.eclipse.jetty.server.Server.handle(Server.java:351) at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:451) at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:916) at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:647) at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:233) at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:76) at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:615) at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:45) at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:599) at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:534) at java.lang.Thread.run(Thread.java:722)
and if I visit
localhost:8080/MySite/
I see two foldersWEB-INF\
andMETA-INF\
both with size0 bytes
.So it doesn't look like my
.war
-export in Eclipse worked.How do I export my simple Servlet for Jetty using Eclipse?
I have now installed the Jetty WTP plugin for Eclipse, but I can't run this servlet using it:
2012-01-30 10:06:50.322:INFO:oejs.Server:jetty-8.1.0.RC4 2012-01-30 10:06:50.353:INFO:oejdp.ScanningAppProvider:Deployment monitor C:\Users\Jonas\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\webapps at interval 1 2012-01-30 10:06:50.353:INFO:oejdp.ScanningAppProvider:Deployment monitor C:\Users\Jonas\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\contexts at interval 1 2012-01-30 10:06:50.353:INFO:oejd.DeploymentManager:Deployable added: C:\Users\Jonas\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\contexts\MySite.xml 2012-01-30 10:06:50.650:WARN:oejuc.AbstractLifeCycle:FAILED o.e.j.w.WebAppContext{/MySite,file:/C:/Users/Jonas/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/MySite/},C:\Users\Jonas\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0/wtpwebapps/MySite: java.lang.NoClassDefFoundError: org/objectweb/asm/ClassVisitor java.lang.NoClassDefFoundError: org/objectweb/asm/ClassVisitor at org.eclipse.jetty.annotations.AnnotationConfiguration.createAnnotationParser(AnnotationConfiguration.java:111) at org.eclipse.jetty.annotations.AnnotationConfiguration.configure(AnnotationConfiguration.java:73) at org.eclipse.jetty.webapp.WebAppContext.configure(WebAppContext.java:428) at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1208) at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:699) at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:454) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59) at org.eclipse.jetty.deploy.bindings.StandardStarter.processBinding(StandardStarter.java:36) at org.eclipse.jetty.deploy.AppLifeCycle.runBindings(AppLifeCycle.java:183) at org.eclipse.jetty.deploy.DeploymentManager.requestAppGoal(DeploymentManager.java:491) at org.eclipse.jetty.deploy.DeploymentManager.addApp(DeploymentManager.java:138) at org.eclipse.jetty.deploy.providers.ScanningAppProvider.fileAdded(ScanningAppProvider.java:142) at org.eclipse.jetty.deploy.providers.ScanningAppProvider$1.fileAdded(ScanningAppProvider.java:53) at org.eclipse.jetty.util.Scanner.reportAddition(Scanner.java:604) at org.eclipse.jetty.util.Scanner.reportDifferences(Scanner.java:535) at org.eclipse.jetty.util.Scanner.scan(Scanner.java:398) at org.eclipse.jetty.util.Scanner.doStart(Scanner.java:332) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59) at org.eclipse.jetty.deploy.providers.ScanningAppProvider.doStart(ScanningAppProvider.java:118) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59) at org.eclipse.jetty.deploy.DeploymentManager.startAppProvider(DeploymentManager.java:552) at org.eclipse.jetty.deploy.DeploymentManager.doStart(DeploymentManager.java:227) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59) at org.eclipse.jetty.util.component.AggregateLifeCycle.doStart(AggregateLifeCycle.java:58) at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:53) at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:91) at org.eclipse.jetty.server.Server.doStart(Server.java:263) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59) at org.eclipse.jetty.xml.XmlConfiguration$1.run(XmlConfiguration.java:1214) at java.security.AccessController.doPrivileged(Native Method) at org.eclipse.jetty.xml.XmlConfiguration.main(XmlConfiguration.java:1137) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.eclipse.jetty.start.Main.invokeMain(Main.java:457) at org.eclipse.jetty.start.Main.start(Main.java:600) at org.eclipse.jetty.start.Main.main(Main.java:82) Caused by: java.lang.ClassNotFoundException: org.objectweb.asm.ClassVisitor at java.net.URLClassLoader$1.run(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at org.eclipse.jetty.annotations.AnnotationConfiguration.createAnnotationParser(AnnotationConfiguration.java:111) at org.eclipse.jetty.annotations.AnnotationConfiguration.configure(AnnotationConfiguration.java:73) at org.eclipse.jetty.webapp.WebAppContext.configure(WebAppContext.java:428) at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1208) at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:699) at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:454) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59) at org.eclipse.jetty.deploy.bindings.StandardStarter.processBinding(StandardStarter.java:36) at org.eclipse.jetty.deploy.AppLifeCycle.runBindings(AppLifeCycle.java:183) at org.eclipse.jetty.deploy.DeploymentManager.requestAppGoal(DeploymentManager.java:491) at org.eclipse.jetty.deploy.DeploymentManager.addApp(DeploymentManager.java:138) at org.eclipse.jetty.deploy.providers.ScanningAppProvider.fileAdded(ScanningAppProvider.java:142) at org.eclipse.jetty.deploy.providers.ScanningAppProvider$1.fileAdded(ScanningAppProvider.java:53) at org.eclipse.jetty.util.Scanner.reportAddition(Scanner.java:604) at org.eclipse.jetty.util.Scanner.reportDifferences(Scanner.java:535) at org.eclipse.jetty.util.Scanner.scan(Scanner.java:398) at org.eclipse.jetty.util.Scanner.doStart(Scanner.java:332) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59) at org.eclipse.jetty.deploy.providers.ScanningAppProvider.doStart(ScanningAppProvider.java:118) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59) at org.eclipse.jetty.deploy.DeploymentManager.startAppProvider(DeploymentManager.java:552) at org.eclipse.jetty.deploy.DeploymentManager.doStart(DeploymentManager.java:227) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59) at org.eclipse.jetty.util.component.AggregateLifeCycle.doStart(AggregateLifeCycle.java:58) at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:53) at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:91) at org.eclipse.jetty.server.Server.doStart(Server.java:263) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59) at org.eclipse.jetty.xml.XmlConfiguration$1.run(XmlConfiguration.java:1214) at java.security.AccessController.doPrivileged(Native Method) at org.eclipse.jetty.xml.XmlConfiguration.main(XmlConfiguration.java:1137) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.eclipse.jetty.start.Main.invokeMain(Main.java:457) at org.eclipse.jetty.start.Main.start(Main.java:600) at org.eclipse.jetty.start.Main.main(Main.java:82)
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Nagendra Prasad over 12 yearsAlso you can add a plugin in eclipse to connect to you Jetty server via eclipse itself. Try adding new server. and then you can run your application directly within eclipse no need to export to war and then publish to Jetty seperately
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Jonas over 12 yearsSorry, it was a typo by me, I was visiting
localhost:8080\MySite\Servlet
. The URI ``localhost:8080\MyServlet\Servlet` returns404 Not Found
. I will have a look for the plugin, but it should work to export a war-file too. -
Jonas about 12 yearsI changed the servlet-class element from
MyServlet.class
tomy.package.MyServlet
and commented out the@WebServlet
-annotation and now it works. Thanks.