What Java web development environment is the best for absolutely minimizing the build-deploy-test cycle time?
Web development environment: JBOSS, Tomcat, Jetty? Deploy WAR exploded? Copy WAR or use symbolic links? There are factors here I don't know about.
Build-deploy-test cycle? The amount of time it takes to test a change in the browser after making a change to the source code or other resources (including Java source, HTML, JSP, JS, images, etc.).
I am looking to speed up my development by reducing the amount of time I spend watching Ant builds and J2EE containers start. I want the Ruby on Rails experience --- or as close as I can get.
I'd prefer a solution that is web framework agnostic, however if a particular framework is particularly advantageous, then I'd like to hear about it.
Assume all the standard tools are in use: Hibernate, Spring, JMS, etc. If stubbing/mocking support infrastructure is required to make this work, I'm OK with that. In fact, I'm OK with having a development environment that is very different from our production environment if it saves me enough time.
You should probably take a look at Javarebel:
http://www.zeroturnaround.com/javarebel/
and this thread here:
How to improve productivity when developing Java EE based web applications
JBOSS uses Tomcat for its servlet/JSP engine, so that's a wash.
Tomcat does support hot deploy.
Jetty's pretty small and starts quickly, but it doesn't support hot deploy.
Eclipse is merely an IDE. It needs a servlet/JSP engine of some kind. If it's like IntelliJ, you can use any Java EE app server or servlet/JSP engine you'd like.
IntelliJ is pretty darned fast, and you don't have to stop and start the server every time you rebuild. It works off the exploded WAR, so things happen fast.
Building (used to be compiling) is a a sign of our times. We need quick validation of our thoughts and our actions. Whenever I find myself building to many times it is usually a sign that I'm not focused. That I don't have a plan. For me this is the time to stop and think. Do a list of things that need to be done (this is web framework agnostic) do them all and test them all after one build.
Jboss Seam together with the Jboss Developer Studio is good for hot deploying everything aside from EJBs (SLSB, SFSB and Entities need redeploy).
Have you considered Grails?
Deployment is as fast as it can get with Google App-Engine + GWT (optional) + Eclipse Plugin.
Never seen anything faster.
Maven 2 and eclipse. mvn eclipse:eclipse <- pure awesomeness. Also, WTP within eclipse works great (and maven generates working WTP projects).
Small web containers will load faster than overloaded webcontainers with the kitchen sink built in (.. cough .. jboss ).
Some design decisions slow build times (e.g. aspect-weaving based toolkits add an aspect-weaving phase to compile times).
Avoid building components that can only be tested after long elaborate load cycles. Caches are a prime culprit here. If your system has deep dependencies on a global cache scattered everywhere you'll need to load the cache every time you need to test something.
Unit-testable components, so you can run pieces instead of the whole thing.
I find that projects built reasonably compile, deploy, and startup in a few to 10 seconds, which is usually fine.
GWT in eclipse is probably the fastest I can think of. Using the hosted mode browser for your tests you can debug and change your code without restarting anything. Just need to click the refresh button in the browser and the changes are there (java, css, etc). One other thing is that GWT is adding this same support to normal browsers (Firefox, IE, Safari) so you can debug from within them the same way. These changes are coming in 2.0. See http://code.google.com/events/io/sessions/GwtPreviewGoogleWebToolkit2.html
Have you tried using Eclipse Java EE and then tell it to deploy to a server managed by Eclipse? Tomcat and JBOss works pretty well in this way. Also allow you to change code in a method, use Ctrl-S and have the class updated inside the server.
MyEclipse also works pretty well like this.
JRuby on Rails. Develop on whatever platform you want, deploy to standard Java servers.
I think the best way to avoid the long build deploy tests cycles is writing unit tests for your code. This way you can find bugs without waiting for the build/deploy phases.
For JSP you can edit the JSP files directly in the JBOSS work folder:
> cd $JBOSS_HOME/server/default/tmp
> find -name myJspFile.jsp
./tmp/vfs/automountd798af2a1b44fc64/Jee6Demo.war-bafecc49fc594b00/myJspFile.jsp
If you edit the file in the tmp folder you can test your changes just hitting the browser refresh button.
Related
I have a Java Spring Boot Application, and I build it with Maven. With
spring-boot-maven-plugin,
I can create fat, executable jar file.
Then I copy it to the remote server and run. But sometimes,
I change only one line or event one word in my code and I had to do whole build/copy step again. I'm sure that I'm doing it wrong, but I couldn't find another way that more efficient (Like capistrano in Rails).
At this point, I'm planning to clone source code to server, push from local, pull from remote, build and run approach. What is the correct (or elegant) way of doing this deployment?
For automatic build and deployment process (continuous integration), you can use Jenkins. Refer this documentation for more details: https://jenkins.io/doc/
I would say it depends where are you trying to do it.
The best and the most agile way to do it for a controlled environment is surely a CI-CD (Continuous Integration and Continuous Deployment) pipelines, which complies-builds-tests-deploys your code against every commit made to the source code BUT it may be too slow to use CI-CD for a development environment where you had like to have a shorter feedback cycle and faster feedback to see how the code is progressing.
However, if you are talking about development environment, I will hit another chord and ask you why to deploy to the external server AT ALL while developing. When you use Spring Boot, which helps you develop a self-contained application, you get the Tomcat Server embedded with it for free. That gives you the choice to run the code anywhere you develop and test to move forward.
A simple maven goal - mvn spring-boot:run can make the code run anywhere you had like.
There is another magical library available in Spring-Boot, known as Devtools, which is meant to support agile developers. The library once in the app classpath, performs hot-swapping of byte-code to auto reload of code into the running application (running locally with embedded Tomcat) as soon there is a saved change. This is one of the coolest gadget that a developer can have.
Use of Spring-Loaded (or JRebel for non spring-boot apps) libraries can also help a developer do hot-swapping of byte code to load changes in running application as soon saved.
I hope it helps.
I'm trying to build a Dynamic Web Application in Eclipse and I'm having trouble when I test my changes.
Sometimes when I make changes, I relaunch the Tomcat server and behold, my project looks exactly the same as last time. I then clean and rebuild the project a few times as well as clean the server, and finally my changes are visible.
This is time consuming and doesn't feel correct.
Is there a proper, quicker, more efficient way to launch a clean copy of your project on the local server?
I have used the Eclipse Tomcat plugin for years with no issues and more recently the Spring Tools Suite with plugin for their customized Tomcat. As you say having your project Build Automatically and having the Server configuration, via the plugin, set to Publish Changes Automatically goes some way towards alleviating the pain of Java web development.
For non Java files (JSP, CSS, JSF, JS etc.) you should see the changes instantly. For Java files, the plugin will reload the application to reflect the changed classes. While this works okay for small applications, for large applications the reload time can become significant. There can also be issues with permgen after multiple reloads and you can lose your session and be booted back to some previous screen and have to step back through the various screens to see your changes.
The ultimate solution then is to use a tool called JRebel which will swap you updated classes into the running VM without the requirement to reload the whole application as well as publishing non java files, reloading application config files (log4J, Spring) managing JPA entities and a lot more.
http://zeroturnaround.com/software/jrebel/
It's a commercial product and while not exactly cheap, in my experience worth every penny. I've been using it for years and couldn't live without it. Your productivity will increase x-fold especially when working on larger applications. No connection, just a satisfied customer.
For a free alternative see:
http://www.hotswapagent.org
In my experience, the tomcat plugin in eclipse has been flaky like this from the beginning. I suggest that you not use it - its just not worth the trouble.
There are at least two alternatives.
First, you could just install tomcat locally, build your war file, and deploy it manually.
A better alternative IMHO is to set up a maven build for your project, and then install the maven tomcat plugin, which just works. I've never seen it get flaky.
Something similar is probably available for gradle, if you want to use that instead of maven.
I've discovered that selecting Build Automatically, under the Projects menu item, changes in the code are automatically recompiled and added to the currently running Tomcat server instance.
Now it's going great! Much faster!
I used playframework previously. Development with play! is so fast. It has an internal java compiler and all the actlon methods are static. So the result is awesome.
Nowadays i use spring on netbeans. Netbeans has a deploy on save feature. But redeployment time is greater than 10 seconds. I used jrebel. But jrebel does not give the same effect. I used eclipse. Eclipse is worst than netbeans. Why java development should be so difficult? Is there any method for fast redeployment?
You have already mentioned JRebel. There are other options, but they are not faster. For example, WTP plugin for Eclipse. You can use jetty-maven plugin, you can use emended jetty-server for development. You can use file-sync plugin for Eclipse. This is 3 most popular and fastest way to deploy project. But all of them require redeploy of server.
You will never get this speed like Play framework or some dynamic compiler language. But probably it's not necessary ?
If you change static resources, like jsp, js, css, you don't need deploy. If you change Java code, just test your code with JUnit or something else. Or write a bunch of code and make deploy
IMHO the more experience you gain, rarely you make deploy =) You don't need to check, what's going on, because you know exactly, what you are doing =)
The reason why Play deployment is so fast, is that it isn't an actual deployment in the original sense of the word. Play checks for the modifications in your Java code, then takes just that file and compiles it and changes the state of the JVM to incorporate the new class.
A real deployment to an application server or event to "just" a servlet container is more than that. The package (war, ear) has to be expanded. Internal structures of the app server has to be updated and the app has to be started. This all takes time because much more components are working together.
What are the implications of building a java program against the jars of one web container (say Jetty) and running it in another (say Tomcat)?
I have an application which I run in Jetty durring development but which is deployed into a tomcat server for production (Why? because it seems easier to develop without having to run a whole tomcat server.)
You should compile against only the official Java EE API's for the level you target, for any non-developer builds. Preferably by a build engine. Preferably on a different operating system than you develop on.
For a web application this mean the appropriate servlet API as downloaded from Oracle. Similar for an enterprise application.
In my experience this is the best way to keep it straight.
Edit: Java EE SDK is available from http://www.oracle.com/technetwork/java/javaee/downloads/index.html. If you need an older version than Java EE 6, then follow the "Previous Releases" link.
You can get issues such as MethodNotFoundError. You can usually resolve these by making sure versions of jars installed on the servers match.
you typically want to develop where you deploy. It might be slightly harder to develop with tomcat vs jetty, but you have identified a potential mess of a problem with jar conflicts, so doesn't it seem worth it to develop with tomcat, since you deploy to tomcat?
Also, typically the pain of developing against tomcat/your container of choice is mitigated by putting in the time to write a ant (or other) task that will deploy your code to your development container. The work cycle bemoes
1) Write new code
2) make sure tests pass
3) run your 'redeploy' script
4) poke around in the running instance
You probably want to do that.
Finally, in the spirit of loose coupling, you probably do not want to depend on a container-specific libraries if you can avoid it; only do that as an absolute last resort.
I currently have Apache HTTP Server, but I'm guessing I'll need Tomcat (and then have to configure it in a way that makes it not open to the public), a Java JDK (which I already have, but should probably update), and an IDE (I have Eclipse). But what else should I have or know before starting?
Lets see... you'll need:
A JDK. Preferably the Standard Edition, unless you plan on using GlassFish as a J2EE server. If you do use the standard edition, you need to include the jars from your servlet container/J2EE stack to access J2EE libraries.
A Servlet container. Apache Tomcat is a popular one, and Eclipse already has integration support for it. Keep in mind that Tomcat is not a complete J2EE stack... you need something like JBoss Application Server or Apache Geronimo for that.
(Semi-Optional) A web server. Apache Web Server surprisingly works well with Apache Tomcat or Apache Geronimo... it's almost like they were made by the same people! Eclipse has built-in support for Tomcat and doesn't appear to require a web server because of it. I could be wrong, though.
(Optional) An IDE. If you use Eclipse, get the version for Java EE Developers.
(Optional) A Database. MySQL and HSQLDB are popular ones for Java, at least for small to medium applications. Keep in mind that you also need to download the JDBC drivers for your database.
(Optional) A revision control system. Even on a single-developer project, a revision control system can save your hide if you accidentally remove code or a file that you shouldn't. There are several choices here; Subversion is my personal choice, along with an Eclipse plugin for it, such as Subclipse.
I'd recommend having a database server installed as well- you can go pretty far with the various pure Java implementations, but anything significant will probably benefit from having a copy of MySQL around.
I'd also get some sort of version control going- tortoiseSVN works really well for windows. Even if you're just goofing around for yourself, getting in the habit of using it will save time and heartache down the road.
If you're trying to stay pretty simple you have everything you need; a servlet container.
The IDE of course helps.
I would recommend Eclipse's Web tools project as it will allow you to code, and then hit a button that will put that code on tomcat all from the IDE.
http://www.eclipse.org/webtools/
As Bogdan mentioned maven is a dependency management tool but depending on your level of comfort I'm not sure if you want to muddy the water with that yet.
Another project that uses Maven is appfuse (http://appfuse.org/display/APF/Home) and will help you get off the ground quickly for generating a webapp. It will give you a webapp, a database, unit tests, dependency management, and a good skeleton to structure your project off of.
So, if you're just wanting to play around with some .jsps and a servlet or two I would stick with the IDE, but if you're comfortable with web applications, MVC, and build tools I'd recommend appfuse.
That's all you need from the tools.
Then, you need to google some tutorial on using servlets and jsp pages. Even documentation bundled with tomcat is good enough.
You'll probably also want a database like MySQL or HSQLDB. You could replace Tomcat with Jetty which is often easier to get class changes to reload without restarting the server.
You can do everything from within NetBeans if you're willing to switch IDEs (it's a relatively painless switch, but you might be able to create a similar setup in Eclipse). There's a Tomcat plugin for NetBeans that allows you to create, edit, run, and debug servlet and JSP web apps all from within NetBeans. There's a starter tutorial here. When you install the Tomcat plugin, you get lots of good example servlets and JSPs as a bonus.
I would go for maven.
It will give you a quick start in configuring your project (by using archetypes) and it will manage your dependencies.
Install it and run the archetype command to create your project.
mvn archetype:create -DgroupId=com.mycompany.app -DartifactId=my-webapp -DarchetypeArtifactId=maven-archetype-webapp
After that just use the maven eclipse plugin to configure your eclipse environment for that project (http://maven.apache.org/plugins/maven-eclipse-plugin/).
I currently have Apache HTTP Server, but I'm guessing I'll need Tomcat (and then have to configure it in a way that makes it not open to the public)
For simple Java based web applications, you need not have Apache installed unless you are too concerned about performance and want to gain by letting Apache serve static resources.
But what else should I have or know before starting?
A good IDE is most recommended, otherwise the development will become painful. Use a simple database as people have already suggested. I would go with MySQL because its neither too complex for a webapp nor too trivial.
Instead of Tomcat I recommend Jetty, that is also a Servlet-Container. In my experience it's easier to setup and maintain. Good enough to test your application.
Other than that you need a JDK (naturally). A database is optional, but if your web-app wants to save data it's the best option.
Step 1:you need to have J2EE installed in your system if not download it from http://www.oracle.com/technetwork/java/javaee/downloads/index.html here.
Step 2: Should have Apache TomCat server to run your web project on your system locally(local Server).
installation steps https://www.ntu.edu.sg/home/ehchua/programming/howto/Tomcat_HowTo.html go to this website.
Step 3:set Class path for java JRE.