Embedded Jetty Server Classpath Issue

Question

I'm trying to deploy a web application on an embedded Jetty Server. My application runs fine locally in a windows environment with the code below but when i deploy it as a JAR File on a Linux Server, it looks like my web.xml File is not picked up. Is there something i need to change in Descriptor or ResourceBase fields below before building a JAR?

static void startJetty() {
        try {
            Server server = new Server(9090); 
            WebAppContext context = new WebAppContext();
            context.setDescriptor("/WEB-INF/web.xml");                     
            context.setResourceBase("../DemoWithMultiChannels/src/");
            context.setContextPath("/");            
            context.setParentLoaderPriority(true);   
            server.setHandler(context);

            System.out.println("Starting Server!");             
            server.start(); 

Answer 1

Deploy embedded Jetty as follows:

Main Class

public static void main(String[] args) throws Exception {
   Server server = new Server(8085);         

    WebAppContext webContext = new WebAppContext();
    webContext.setDescriptor("WEB-INF/web.xml");
    webContext.setResourceBase("src/sim/ai/server/start");      
    webContext.setServer(server);
    webContext.setParentLoaderPriority(true);
    server.setHandler(webContext);

    server.start();
    server.join();
}

web.xml

<!DOCTYPE web-app
    PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
    "http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>
    <display-name>sim.ai.server.start</display-name>
    <servlet>
        <servlet-name>Jersey REST Service</servlet-name>
        <servlet-class>
        com.sun.jersey.spi.container.servlet.ServletContainer
        </servlet-class>
        <init-param>
            <param-name>com.sun.jersey.config.property.packages</param-name>
            <param-value>sim.ai.server.start</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
      <servlet-name>Jersey REST Service</servlet-name>
      <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>
</web-app>   

Create a WEB_INF folder in the same folder as the jar file; copy web.xml into WEB_INF, such as:

sim/light.jar
sim/WEB-INF/web.xml

Answer 2

Here is how to do it.

First, in your pom.xml, declare where the webapp folder is:

 <build>
    <resources>
       <resource>
            <directory>src/main</directory>
       </resource>
    </resources>

Here is the tree of my src/main directory:

├── java
│   └── com
│       └── myco
│           └── myapp
│               └── worker
│                   ├── App.java
|                    ...
├── resources
│   ├── log4j.properties
│   └── version.properties
└── webapp
    ├── index.html
    ├── index.jsp
    ├── lib
    │   ├── inc_meta.jsp
    │   └── inc_navigation.jsp
    ├── query.html
    ├── scripts
    │   ├── angular.min.js
    │   └── bootstrap.min.css
    ├── showresults.jsp
    ├── status.jsp
    └── WEB-INF
        └── web.xml

Add Maven Shade plugin in your pom.xml file:

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-shade-plugin</artifactId>
            <version>2.3</version>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>shade</goal>
                    </goals>
                </execution>
            </executions>
            <configuration>
                 <finalName>uber-${artifactId}-${version}/finalName>                            
            </configuration>                                        
        </plugin>

Then start Jetty like this:

public static void startJetty() throws Exception {
    logger.info("starting Jetty...");

    Server server = new Server(8080);
    WebAppContext webAppContext = new WebAppContext();
    webAppContext.setContextPath("/");

    /* Important: Use getResource */
    String webxmlLocation = App.class.getResource("/webapp/WEB-INF/web.xml").toString();
    webAppContext.setDescriptor(webxmlLocation);

    /* Important: Use getResource */
    String resLocation = App.class.getResource("/webapp").toString();
    webAppContext.setResourceBase(resLocation);

    webAppContext.setParentLoaderPriority(true);

    server.setHandler(webAppContext);

    server.start();
    server.join();
}

The important part is to use <YourApp>.class.getResource(<your location>) that will give the path to the files inside the jar. The wrong way would be to do it like this: webContext.setDescriptor("WEB-INF/web.xml"); which gives the path on the file system.

Then create package

$mvn clean package

The uber-jar file is generated and contains the webapp directory that was declared as resource.

Move the jar anywhere or on the production server and run it like this:

$ java -jar myjettyembededwithwebxmlandhtmljspfile.jar

Answer 3

I have replaced WebAppContext and WebXmlConfiguration with specific descendants which can find resources in classpath:

Server: https://github.com/jreznot/diy-remote/blob/master/server/src/org/strangeway/diyremote/server/RemoteServer.java

WebAppContex: https://github.com/jreznot/diy-remote/blob/master/server/src/org/strangeway/diyremote/server/sys/ClasspathWebAppContext.java

WebXmlConfiguration: https://github.com/jreznot/diy-remote/blob/master/server/src/org/strangeway/diyremote/server/sys/ClasspathWebXmlConfiguration.java

It works good for me

Answer 4

I had the same problem and just found the solution:
It was working fine when I run "java -jar ..." from terminal, but when I spawned it off from another project, web.xml was not picked up.

Reason was web.xml path was wrong, it was relative to original project, what I end up doing is:

context.setDescriptor(Launch.class.getResource("/WEB-INF/web.xml").toString());

If you don't use resource you just read the regular file inside your src folder, not the one inside the .jar