Modifying Configuration for Embedded tomcat webapp - heroku

Question

I've been trying to modify embedded tomcat configuration for my heroku app. I've installed heroku app using the wiki link below that configures a simple embedded tomcat.
http://devcenter.heroku.com/articles/create-a-java-web-application-using-embedded-tomcat
The source code is here:
public static void main(String[] args) throws Exception {
String webappDirLocation = "src/main/webapp/";
Tomcat tomcat = new Tomcat();
//The port that we should run on can be set into an environment variable
//Look for that variable and default to 8080 if it isn't there.
String webPort = System.getenv("PORT");
if(webPort == null || webPort.isEmpty()) {
webPort = "8080";
}
tomcat.setPort(Integer.valueOf(webPort));
tomcat.addWebapp("/", new File(webappDirLocation).getAbsolutePath());
System.out.println("configuring app with basedir: " + new File("./" + webappDirLocation).getAbsolutePath());
tomcat.start();
tomcat.getServer().await();
}
Questions:
Since I'm using embedded tomcat, how do I configure default session timeout for my web application? It seems to default to 30 min for some reason? I want to set to something like one week.
If I launch the application from within eclipse, how do I set autodeploy = true so that I don't have to compile and restart my application every time I modify java code?
is there way to set my web.xml and server.xml?
how do I run apache tomcat manager?
The documentation on the internet is not very clear. Can you please help?
Thanks in advance..
Kiran

Answer 1

Use Context.setSessionTimeout(int). Java docs here. Here's the same Main class with a session timeout set to 30 days:
package launch;
import java.io.File;
import org.apache.catalina.startup.Tomcat;
import org.apache.catalina.Context;
public class Main {
public static void main(String[] args) throws Exception {
String webappDirLocation = "src/main/webapp/";
Tomcat tomcat = new Tomcat();
//The port that we should run on can be set into an environment variable
//Look for that variable and default to 8080 if it isn't there.
String webPort = System.getenv("PORT");
if(webPort == null || webPort.isEmpty()) {
webPort = "8080";
}
tomcat.setPort(Integer.valueOf(webPort));
Context ctx = tomcat.addWebapp("/", new File(webappDirLocation).getAbsolutePath());
ctx.setSessionTimeout(2592000);
System.out.println("configuring app with basedir: " + new File("./" + webappDirLocation).getAbsolutePath());
tomcat.start();
tomcat.getServer().await();
}
}
Notice the Context ctx = ... and ctx.setSessionTimeout(...).
As for Tomcat Manager, you can't use it when you embed Tomcat in your application this way. I am curious what you would like to use Tomcat Manager for?
Anything you would normally do from server.xml you can do via the embed API. The whole point of embedding is that you configure everything programmatically.
You can still set up your own web.xml as you normally would. Just add it in a WEB-INF directory under the directory you pass in as webappDirLocation. But again, I am curious what you would want to put in web.xml? Because you "own" the main application loop, you can set up any configuration you need from your main method. I highly recommend a practice of initializing everything you need in the main loop and reading OS environment variables for anything that is environment specific (e.g. a JDBC url).
Finally, as for Eclipse, you don't need hot deploy anymore because you are not using a container deployment model. You can simply run your application from inside Eclipse with "Debug as..." and Eclipse will auto compile and reload code as you change it. It's not exactly similar to hot deploy. For example, it won't hot reload classes with new method signatures. But it's much faster to cycle the whole app compared to when using a container, so overall, I find it much more productive.