James embedding

[Goran Markovic]

Hi, I find some James embedding example on this url, Embeddable James, but I don't really get how to relate, the refined MAIN class of author (the args argument) and the servlet code 9inside what args variable has been used).? This is the code of lunchJAMES servlet:

public class launchJAMES extends HttpServlet {

    protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/plain");
        PrintWriter writer = response.getWriter();
        try
        {
            System.setProperty( "phoenix.home", "C:\\Documents and Settings\\Owner\\Desktop\\\\james-2.2.0" );
            System.setProperty( "catalina.home", "C:\\Program Files\\Apache Software Foundation\\Tomcat 5.5");
            URLClassLoader childClassLoader =
                new URLClassLoader(
                    new URL[] {           
                        new File("C:\\Documents and Settings\\Owner\\Desktop\\james-2.2.0\\bin\\phoenix-loader-modified.jar").toURL()
                });
            final Class mainClass = childClassLoader.loadClass( "org.apache.avalon.phoenix.launcher.Main" );
            final Class[] paramTypes =
                new Class[]{args.getClass()};
            final Method method = mainClass.getMethod( "main", paramTypes );
            Object main_instance = mainClass.newInstance();
            method.invoke(main_instance, new Object[]{args} );
        }
        catch (Exception e)
        {
                e.printStackTrace();
        }
        writer.flush();
        writer.close();
    }
  }

and this is working version of Main with functions that were added or modified :

public final class Main
{
    private static final String MAIN_CLASS =
        "org.apache.avalon.phoenix.frontends.CLIMain";
    /* 
     * Note: This is changed from phoenix-loader.jar to phoenix-loader-modified.jar
     * for this example 
     */
    private static final String LOADER_JAR = "phoenix-loader-modified.jar";
    private static Object c_frontend;

    /* Comment out the System.exit statement. We work with Tomcat not alone anymore */
    public static final void main( final String[] args )
        throws Exception
    {
        final int exitCode =
            startup( args, new HashMap(), false );
        //System.exit( exitCode );
    }

    public static ClassLoader phoenixHomeClassLoader()
    {
        File[] libjars = (new File(System.getProperty( "phoenix.home" )+"/lib")).listFiles(new FilenameFilter() {
                public boolean accept(File dir, String name) {
                        return (name.endsWith(".jar"));
                }});
        File[] binjars = (new File(System.getProperty( "phoenix.home" )+"/bin")).listFiles(new FilenameFilter() {
                public boolean accept(File dir, String name) {
                        return (name.endsWith(".jar"));
                }});
        File[] binlibjars = (new File(System.getProperty( "phoenix.home" )+"/bin/lib")).listFiles(new FilenameFilter() {
                public boolean accept(File dir, String name) {
                        return (name.endsWith(".jar"));
                }});
        File[] catalinajars = (new File(System.getProperty( "catalina.home" )+"/shared/lib")).listFiles(new FilenameFilter() {
                public boolean accept(File dir, String name) {
                        return (name.endsWith(".jar"));
                }});
        List jarURLs = new ArrayList();
        for (int i=0; i<libjars.length; i++)
        {
                try
                {
                        jarURLs.add(libjars[i].toURL());
                }
                catch (Exception e)
                {
                        e.printStackTrace();
                }
        }
        for (int i=0; i><binjars.length; i++)
        {
                try
                {
                        if (!binjars[i].getName().equalsIgnoreCase("phoenix-loader.jar"))
                                jarURLs.add(binjars[i].toURL());
                }
                catch (Exception e)
                {
                        e.printStackTrace();
                }
        }
        for (int i=0; i><binlibjars.length; i++)
        {
                try
                {
                        jarURLs.add(binlibjars[i].toURL());
                }
                catch (Exception e)
                {
                        e.printStackTrace();
                }
        }
        for (int i=0; i><catalinajars.length; i++)
        {
                try
                {
                        jarURLs.add(catalinajars[i].toURL());
                }
                catch (Exception e)
                {
                        e.printStackTrace();
                }
        }       URL[] returnVal = (URL[])jarURLs.toArray( new URL[ jarURLs.size() ] );
        return new URLClassLoader( returnVal, Main.class.getClassLoader() );            
    }

    protected static final int startup( final String[] args,
                                        final Map data,
                                        final boolean blocking )
        throws Exception
    {
        int exitCode;
        try
        {
            //setup new Policy manager
            Policy.setPolicy( new FreeNEasyPolicy() );

            //Create engine ClassLoader
            final URL[] urls = getEngineClassPath();
            final URLClassLoader classLoader = new URLClassLoader( urls );

            /* 
             * We build our own classloader which searches for the PHOENIX_HOME directory 
             * for jars 
             */
            ClassLoader commonLibClassLoader = phoenixHomeClassLoader();
            data.put( "common.classloader", commonLibClassLoader );
            data.put( "container.classloader", classLoader );
            data.put( "phoenix.home", new File( findPhoenixHome() ) );            

                        
            //Setup context classloader
            //Thread.currentThread().setContextClassLoader( classLoader );

            //Create main launcher
            final Class clazz = commonLibClassLoader.loadClass( MAIN_CLASS );
            final Class[] paramTypes =
                new Class[]{args.getClass(), Map.class, Boolean.TYPE};
            final Method method = clazz.getMethod( "main", paramTypes );
            c_frontend = clazz.newInstance();

            //kick the tires and light the fires....
            final Integer integer = (Integer)method.invoke(
                c_frontend, new Object[]{args, data, new Boolean( blocking )} );
            exitCode = integer.intValue();
        }
        catch( final Exception e )
        {
            e.printStackTrace();
            exitCode = 1;
        }
        return exitCode;
    }
    /*
     * The other methods namely shutdown, getEngineClassPath, findEngineLibDir, 
     * findPhoenixHome, and findLoaderDir are unmodified and hence not shown here.
     */
  }

Is this way of embedding achievable ( I also find some quite obscure means of James embedding in association with Spring) ?>

[Ulf Dittmer]

This seems to use separate classloaders for James; is that necessary in your case? I'd just drop all the libraries into WEB-INF/lib, and use a context listener to start a background thread that calls the standard main method.

[Goran Markovic]

No of course, it's not necessary but was the only example of embedding James. So, you suggest to copy each libraries from james source (there is few lib. folders containing many libraries. Do I need some particular like phoenix-loader.jar), and in the web.xml ( I'm gonna try to add it into .war apps. to place something like this :

<listener>
<listener-class>com.example.MyContextListener
</listener-class>
</listener>

and in the class MyContextListener, to do somthing like this :

contextInitialized(ServletContextEvent){

org.apache.avalon.phoenix.launcher.Main james = new org.apache.avalon.phoenix.launcher.Main();
}

Is that what you think?

[Goran Markovic]

No, it was just ridiculous thought. I try it really I do not get it...

[Ulf Dittmer]

That is pretty much exactly what I was thinking of.

[Goran Markovic]

yeah? But nothing's happens.. I cannot send messages between users (probably because James hasn't started).I wrote this testing listener:

package test;

import javax.servlet.*;

public class MyListener implements ServletContextListener {
public void contextInitialized(ServletContextEvent event) {

org.apache.avalon.phoenix.launcher.Main james = new org.apache.avalon.phoenix.launcher.Main();  
}  

public void contextDestroyed(ServletContextEvent event) {
// nothing to do here
}
}

and this mapping ;

<listener>
<listener-class>test.MyListener
</listener-class>
</listener>

<welcome-file-list>
<welcome-file>Welcome.jsp</welcome-file>
</welcome-file-list>

When I type address http://www.localhost.com:8080/James_Test/, the Welcome.jsp page would open, and nothing ( I believe that myListener class should be invoked on servletcontext startup, and create instance of Main class. Probably I need to invoke some method of James (like I start it from command line typing run.bat). If so, what is that method?

[Ulf Dittmer]

But nothing's happens

I wouldn't expect anything visible to happen, since James has no GUI.

I cannot send messages between users

What happened when you tried?

[Goran Markovic]

Well, nothing. I even monitor number of processes when I start server, and no more is added (unlike when I start James by command prompt). However, when I open outlook I get follow error :

The connection to the server has failed. Account: '127.0.0.1', Server: '127.0.0.1', Protocol: POP3, Port: 110, Secure(SSL): No, Socket Error: 10061, Error Number: 0x800CCC0E

It mean, that James hasn't started, i think, because, when I start it by run.bat, I can perform sending/receiving of messages between users.

[Goran Markovic]

One more thing. In my application lib-folder, I store only phoenix-xxx.jar, jar files and mx4j-tools.jar. If I include all from JAMES_HOME/lib, and JAMES_HOME/tools, and JAMES_HOME/bin/lib, I continuously receive an exception and failed deployment of application...

[Ulf Dittmer]

I even monitor number of processes when I start server, and no more is added (unlike when I start James by command prompt).

The number of processes wouldn't change, because it runs inside the JVM (which is just one process).

The connection to the server has failed. Account: '127.0.0.1', Server: '127.0.0.1', Protocol: POP3, Port: 110, Secure(SSL): No, Socket Error: 10061, Error Number: 0x800CCC0E

Not sure what that's trying to tell us, but it sure doesn't look good. But "Account: '127.0.0.1'" looks particularly strange, as if the code were using "127.0.0.1" for the username.

In my application lib-folder, I store only phoenix-xxx.jar, jar files and mx4j-tools.jar. If I include all from JAMES_HOME/lib, and JAMES_HOME/tools, and JAMES_HOME/bin/lib, I continuously receive an exception and failed deployment of application...

I'd expect all jar files to be needed; if there are exceptions I'd start by tracking those down. It's possible that there are version conflicts with other jar files your code -or the servlet engine- uses.

You could also make this a separate web app, independent of the one that runs your other application code.

[Goran Markovic]

well, 127.0.0.1, was name of account nothing special. I have change it. I've delete applications from Tomcat's deployment directory, so this is the only. There is something wrong about some arguments, and excalibur.jar I have nowhere on my classpath. I just have configured PHOENIX_HOME environment variable. This is the stack trace ;

SEVERE: Error deploying web application directory Jame
java.lang.IllegalArgumentException: oro,excalibur-i18n,excalibur-extension-Extension-Name
	at java.util.jar.Attributes$Name.<init>(Attributes.java:447)
	at java.util.jar.Attributes.getValue(Attributes.java:99)
	at org.apache.catalina.util.ManifestResource.getRequiredExtensions(ManifestResource.java:186)
	at org.apache.catalina.util.ManifestResource.processManifest(ManifestResource.java:155)
	at org.apache.catalina.util.ManifestResource.<init>(ManifestResource.java:52)
	at org.apache.catalina.util.ExtensionValidator.validateApplication(ExtensionValidator.java:186)
	at org.apache.catalina.core.StandardContext.start(StandardContext.java:4064)
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:760)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:740)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:544)
	at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:927)
	at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:890)
	at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:492)
	at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1150)
	at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:311)
	at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:120)
	at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1022)
	at org.apache.catalina.core.StandardHost.start(StandardHost.java:736)
	at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1014)
	at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
	at org.apache.catalina.core.StandardService.start(StandardService.java:448)
	at org.apache.catalina.core.StandardServer.start(StandardServer.java:700)
	at org.apache.catalina.startup.Catalina.start(Catalina.java:552)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:295)
	at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:433)