I'm running a webapp through Spring MVC whose backend is written in Java. I am working in Eclipse. I'm trying to make changes to the java code (which I did not write, but am tasked with editing).
However, none of the changes I make do anything. I tried manually compiling the project in Eclipse (Project -> Build Project) but nothing happened. I even tried taking out one of the .class files to see if it would be recompiled and it was not. The directory which should have contained that file remained empty.
I've already checked and the source and deployment paths match the places in which the .java and .class files I'm working with are located. What the heck is Eclipse doing and how can I make it compile my files?!?
Take a look at
How does Eclipse deploy Web Application using Tomcat
Did you remove the deployed app under:
{Workspace_location}/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps
Related
I have a running Java web application from a previous employee which I am trying to fix. I literally just need to fix one line in .java file. However, I have problems rebuilding it and running the new version with Tomcat. When I try to rebuild the files, it doesn't actually change any of the source files.
I'm at a bit of a loss when it comes to going about recompiling/rebuilding the .java files. Do I need any additional tools for it?
You can import the project in to an IDE and add ant task then run build.xml to build your project. After that you can change your java class and build the project then get the class file and replace it into old project
I have a little java project which is build in gradle. I imported the project to eclipse. The gradle task run starts the server and run the application in localhost(using Tomcat). Problem is, how to refresh my .java data instead of re-run the application always again. This takes time. I can change my .jsp files in build directory and after page refreshing data changes. But problem is .java files. In gradle there are task install which compile the whole project(shows errors if have), but the page content doesnt change, so i have to run project again to see the changes.
I have .class-es in 2 places. In build directory and exploded/WEB-INF. IMO, if application runs, it is using build directory files, but i dont know what files are in WEB-INF directory...
Redeployment has always been a great time consumer. There are a couple of tools(some comercial) that will help you, like JRebel. If you want to use Netbeans, there is a deploy on save option too. I don't know any other options, I'm sure there are a few more, but anyway, this should be a good start.
The easiest way is to start your application with debugger flags, then every time you update and compile your source code, the JVM will pick-up a new version automatically, without redeployment, it is called "hot-swapping".
You will need to add something similar to your run task:
-Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5005
Then attach Eclipse debugger to localhost:5005 and you will be good to go. It will not work if you are changing method signatures, add new class attributes or constants. Apply your changes within existing methods, then once everything works as expected, refactor and restart.
More information on debugging with Eclipse: Debugging With Eclipse Platform
I've got a Java Web Project which I'm deploying to a Tomcat embedded in Eclipse's Servers Plugin, alas, when I navigate to the location of that webapp after publishing/starting the server, the .class files are all missing. I can navigate as far as ProjectName\WEB-INF\classes\path\to\packages\ -> All packages are empty.
Any Idea how to solve this problem?
Edit
Build Automatically is checked and it compiles just fine for another web project I've just included, just not for the one specified
Edit 2
Reinstalled Eclipse (because why not) - nothing's changed, works for Project #2, doesn't work for Project #1. Not even the path to the packages is existant now. The content of the src folder (that's supposed to be moved to WEB-INF/classes) isn't there at all - but the resources (I've got a resources folder with the same deployment assembly command) are.
A few steps to perform to restore sanity...
Refresh your project. It is possible that something was modified on the file system external to Eclipse.
Kick of Project -> Clean.
Now look at your project (not the deployed location) on the file system. Do you see the expected files in the /bin directory (or whatever you may have changed class output directory to)?
Let's now try exporting a war using the wizard. File -> Export -> Web -> WAR or something like that. Check the WAR contents. Are you .class files there?
If everything is good so far, there is nothing wrong with your project. The Tomcat server adapter just got confused.
In the Servers view... Make sure Tomcat is running. Next right click on Tomcat and select add/remove projects. Remove your project. Confirm that your web app is no longer accessible.
Now re-add your project via add/remove projects or invoke one of the run as actions.
The above should reset Tomcat server adapter and hopefully things should work as expected.
Check if you had deleted or moved your external JARs associated with the project on your IDE. I had moved it and ran into the same issue.
Alright, so I have a web service that was created using an eclipse dynamic web project. It is currently shared on a CVS repository, but the versioning system used is irrelevant. At the moment, I have literally NEVER been able to pull this project out as is and get it working. It leads to countless errors that cannot be fixed. Every time I need to work on this webservice in a new machine I have to create an entirely new dynamic project, copy over the source files, add all the necessary libraries and make the deployment assembly work correctly again. After finally making it run I share the project as the same one, stop after a second, and then synchronize again (in a way tricking eclipse into thinking this was the shared project all along).
I feel like others must have run into this problem and found a way around it. So if you have a web service or any dynamic web project, what files do you share, and how do you successfully pull it from the repository and get it to run on another machine besides what I currently do now?
Your help is much appreciated,
-Asaf
Edit: After reading some of the responses I feel that this question is actually more specific to those who use WTP to create/test their web services. Just wanted to add the clarification.
Edit2: Let me also clarify that the other 20 or so projects not using WTP are shared just fine. I am able to pull and run them with no problem. Only web service projects are an issue.
In general, you want to check in everything that's not "derived" (generated or compiled - that's usually the contents of the bin directory or other place where your code is compiled/built into). For Eclipse Java projects, you want to include the .project, .classpath, .settings, and any other similar files that Web Tools might create for Dynamic Web projects. The Eclipse CVS client will ignore files marked as Derived so you shouldn't have to worry to much about it.
Without more detail about what kind of problems you've run into, it's not possible to guess what was causing them. My only guess is that perhaps you had different versions of Eclipse and/or the WTP (Web Tools Platform) plugins installed on the different machine. That's just a wild guess, but could explain some incompatibility when you check out the project from CVS.
Bottom line, checking in those .* files is the long recommended approach from Eclipse gurus. Maven can kind of change things, but you didn't mention it so I'm assuming you aren't using it.
I am primarily sharing my experience, may be you can find some help.
Conceptually speaking, the files which the IDE can generate itself while creating new project should not be pushed. I.e the IDE specific files should not be pushed. And everything which the IDE cannot generate on its own must be pushed.
Forexample in case of eclipse, following files should not be pushed:
.settings
build
.classpath
.project
For setting the project on new machine, first pull the files from server, and then create a project from IDE using pulled files.
EDIT: If your project has external jars/libraries, then you will have to add to the classpath manually. You could also push .classpath but that might give errors while creating a new project.
I think it's easiest to use a build system and let the IDE generate the project from your build system.
Eclipse, Netbeans, and Intellij are all pretty good at building projects from maven or ant build files. With this solution you have a simple build that is easy to setup in CI (Hudson, Bamboo, whatever) and you don't have any IDE specific files checked in. If my workspace is totally different than yours, with different versions, plugins, whatever, I'm not stuck with your project file and you're not stuck with mine. My IDE creates the project appropriate for my environment and your IDE does the same for yours.
Since you mentioned having to manually add libraries, I assume you are not using any build manager (like, maven or ant) besides ecplise.
For ecplise to handle the project properly you need the source files (*.java) in their respective directories, any resources bundled with the web service (e.g. services.xml), the ".project", ".classpath", ".settings", etc. files for eclipse. This should be enough for eclipse to generate anything else necessary to build the project.
Any files/directories that are generated by eclipse during the build process (e.g. target & bin directory, *.class, *.war) should not be checked in -- they will be generated when needed during the build.
I am thinking that, since you are adding the necessary 3rd-party jars manually, these libraries might reside in a different path between computers (e.g. if the path contains the username, it will not be transferable to another computer for a different user). To fix that you can set up the classpath using an eclipse classpath variable. In Preferences->Java->Build Path->Classpath Variables set up a varable linked to the "root" folder where the 3rd party jars a stored. Then add the libraries to the project using this new variable, not their full path. To make it work on someone else's computer, you would only need to set this classpath variable to have the build path point to the correct libraries.
It might be beneficial if you migrated your project from eclipse only to a build manager (e.g. maven) that takes care of many of these issues for you. Eclipse can build a project from the configuration of the build manager, making it easier to manage the project.
I come from an Asp.Net development background and am very comfortable there. I was asked to support an existing Java Web Application w/ struts and am able to figure most of it out with my Asp.Net knowledge and my android development experience. However, I'm having a really simple but stupid problem.
All i have is the website as it exists on the server, no source project to work from. The folder on the server contains both .java and .class files, but the folder doesn't just import into netbeans as a recognized project.
What's the easiest way to get the site imported into some sort of IDE (I can work w/ eclipse too if netbeans isn't recommended), and get it to compile so I can deploy some updates.
It will not be easy to answer fully to your question here. But we should be able to achieve that by steps :)
Here i will speak for eclipse. But it is only because i'm not familiar with netbeans.
First of all create a clean "dynamic web project" under eclipse (using a J2EE enabled eclipse http://www.eclipse.org/downloads/).
Then :
copy your sources files in "Java Resources"
copy the rest of your application (without the class files) in WebContent
In order to test your application localy you will need a local server. Tomcat can be integrated easily in eclipse.
Usually you shouldn't have to (re)construct a project from a deployed web-app; the project should have been kept in version control. Source code isn't usually deployed to the server, either, but if it's been done in this case, you're in luck.
I would just make a new web project in NetBeans and manually move the .java files into it, along with the other resources (except for the .class files).
If you can use eclipse, and the source files are already in the war file as you say. You can import the war file directly into eclipse as project.
file -> import -> war file or existing project into workspce or filesystem (Several other options exists)