While debugging a java app in eclipse I receive a "Source not found" error in two cases:
Stepping in to a file in a different project which is already imported
Stepping in to a file in an installed maven repository
The files are there, but eclipse won't step into them, instead it shows a button to "attach source"
I tried attaching (which opened a dialog to define a variable?!) and eclipse did jump to the file, but the debugger could not inspect any variables there. Also manually attaching the source for each dependency isn't practical, as in my case there are thousands of dependency files.
Why is this happening, and how can it be resolved?
Just 3 steps to configuration Eclipse IDE:
Note: After updating the Source Lookup paths, you'll have to stop and restart your debug session. Otherwise, the file with the missing source will continue to show "missing source".
Edit Source Lookup
Select the Edit Source Lookup... command [ Edit Source Lookup ] to open the Source Path Dialog, which allows you to make changes to the source lookup path of the selected debug target.
IMPORTANT Restart Eclipse after this last step.
Eclipse debugging works with the class actually loaded by the program.
The symptoms you describe sounds like the class in question was not found in the project, but in a distribution jar without debug info found before the project you are working with.
This can happen for several reasons but have a look at the location where the classes showing this behaviour is found (look in the navigation pane to identify it). You will most likely need to change the build path of the project to avoid using this jar and have the JVM use the project instead.
EDIT: Note that as of 2018 it is common to use a build framework like Maven, where the build path is managed by the m2e plugin so this problem should be very less frequent than when the question was asked. If you use Maven and m2e, make sure to enable Preferences / Maven / "Download Artifact Sources" or right-click the project, Maven / "Download Sources".
The symptoms perfectly describes the case when the found class doesn't have associated (or assigned) source.
You can associate the sources for JDK classes in Preferences > Java > Installed JRE. If JRE (not JDK) is detected as default JRE to be used, then your JDK classes won't have attached sources. Note that, not all of the JDK classes have provided sources, some of them are distributed in binary form only.
Classes from project's build path, added manually requires that you manually attach the associated source. The source can reside in a zip or jar file, in the workspace or in the filesystem. Eclipse will scan the zip, so your sources doesn't have to be in the root of the archive file, for example.
Classes, from dependencies coming from another plugins (maven, PDE, etc.). In this case, it is up to the plugin how the source will be provided.
PDE will require that each plugin have corresponding XXX.source bundle, which contains the source of the plugin. More information can be found here and here.
m2eclipse can fetch sources and javadocs for Maven dependencies if they are available. This feature should be enabled m2eclipse preferences (the option was named something like "Download source and javadocs".
For other plugins, you'll need to consult their documentation
Classes, which are loaded from your project are automatically matched with the sources from the project.
But what if Eclipse still suggest that you attach source, even if I correctly set my classes and their sources:
This almost always means that Eclipse is finding the class from different place than you expect. Inspect your source lookup path to see where it might get the wrong class. Update the path accordingly to your findings.
Eclipse doesn't find anything at all, when breakpoint is hit:
This happens, when you are source lookup path doesn't contain the class, which is currently loaded in the runtime. Even if the class is in the workspace, it can be invisible to the launch configuration, because Eclipse follows the source lookup path strictly and attaches only the dependencies of the project, which is currently debugged.
An exception is the debugging bundles in PDE. In this case, because the runtime is composed from multiple projects, which doesn't have to declare dependencies on one another, Eclipse will automatically find the class in the workspace, even if it is not available in the source lookup path.
I cannot see the variables when I hit a breakpoint or it just opens the source, but doesn't select the breakpoint line:
This means that in the runtime, either the JVM or the classes themselves doesn't have the necessary debug information. Each time classes are compiled, debug information can be attached. To reduce the storage space of the classes, sometimes this information is omitted, which makes debugging such code a pain. Your only chance is to try and recompile with debug enabled.
Eclipse source viewer shows different lines than those that are actually executed:
It sometimes can show that empty space is executed as well. This means that your sources doesn't match your runtime version of the classes. Even if you think that this is not possible, it is, so make sure you setup the correct sources. Or your runtime match your latest changes, depending on what are you trying to do.
From http://www.coderanch.com/t/587493/vc/Debugging-Eclipse-Source
"When running in debug mode, right click on the running thread (in threads tab) and select Edit Source Lookup. At this point, you should be able to add the necessary project/jar which contains your source code."
I added my current project in this way, and it solved my problem
I had similar problem with my eclipse maven project. I fought with this issue quite a long time then I tried to rebuild project with
mvn clean eclipse:eclipse
and it helped.
Note: Using this approach will confuse the m2e plugin since the two approaches are very different. m2e adds a virtual node to your project called "Maven Dependencies" and asks Maven to add all dependencies there.
mvn eclipse:eclipse, on the other hand, will create a lot of individual entries in the file .classpath. Eclipse will handle them as if you manually added JARs to your project.
Unless you know how the classpath in Eclipse works, this approach is not recommended.
I was facing the same issue,I followed the bellow steps.
Window => Preferences => Java => Installed JREs,
You see in the above screen Jre1.8.0_12 is selected.
select the JRE you are using and click Edit. Now You should see the bellow screen.
Click on the directory, browse for Jdk, It should look like bellow screen.
click ok, and its done
I had the problem that my Eclipse was not debugging the source code of my project. I was getting a blank page with "Source code node found".
Please click the Attach source code button. Then delete the "default" folder then click add and go to your project location and attach. This worked for me
Remove the existing Debug Configuration and create a new one. That should resolve the problem.
None of the mentioned answer worked for me.
To resolve this issue i have to follow bellow steps:
Right click on Java HotSpot(TM) 64 Bit server.
Select "Edit Source Lookup".
Click on "Add".
Select "File System Directory" instead of Java project.
Select Root directory of your project.
Check "Search Subfolders".
Click Ok ok ok.
Thanks.
Click -> Edit Source Lookup Path
after then
Click -> Add finally select Java project and select project path.
Source: https://www.youtube.com/watch?v=IGIKPY6q1Qw
In my case, even after Editing source lookup and Adding project, it didn't worked. I configured the Build path of the project.
After that, I selected JRE System Library and it worked.
Evidently, Eclipse does not automatically know where the source code for the dependent jars are. It is not clear why debugger could not inspect variables once the source was attached. One possibility is incorrect/incompatible source.
Assuming you have a maven project and the sources of the dependencies are downloaded and available in the local repository, you may want to install m2eclipse, the maven eclipse plugin and see if that helps in addressing your issue.
You might have source code of a dependency accessible to Eclipse. But Eclipse does not know for source code for code that is dynamically loaded. E.g. through Maven.
In case of Maven, I recommend that you use run-jetty-run plugin:
http://code.google.com/p/run-jetty-run/
As a workaround you can also connect to a running JVM with the debugger and you will see the code.
Alternatively you can use Dynamic Source Lookup plugin for Eclipse from here:
https://github.com/ifedorenko/com.ifedorenko.m2e.sourcelookup
Unfortunately it didn't helped me as it has issues with Windows paths with spaces.
I have filled an enhancement request on Eclipse Bugzilla and if you agree this issue "Source not found" should vanish forever, please vote for it here:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=384065
Thanks!
Sasa
In my case in "Attach Source", I added the other maven project directory in the "Source Attachment Configuration" panel. Adding the latest version jar from the m2 repository din't work. All the classes from the other maven project failed to open.
Here test was my other maven project containing all the java sources.
I had the very same problem. In my case, I've disabled Window-Preferences-Java-Debug [Suspend execution on uncaught exceptions]. Then, the console showed me the correct error: my MySql user hadn't privileges to access the database. According to this topic.
Info: This is a possible solution, when you use maven (pom.xml) with couple of projects.
If you are working with maven, make sure what version you are taking inside the according pom.xml (e. g. 1.0.1-SNAPSHOT ).
It might be possible that your code is up-to-date, but your pom.xml dependencies are still taking the old JAR's/Snapshots (with the old code).
Finding the problem:
Try to debug the according file.
Therefore, set a breakpoint in the relevant code area.
When "source not found" appears, make sure to bind in the right project (where the .java file can be found).
The compile .class file opens up in the IDE editor.
Click "Link with Editor" to find the according JAR/Snapshot.
Now make sure that this JAR is the most recent one. Possibly there is a newer one. In that case, write the most recent version number in the pom.xml.
Then do a maven update and build (e. g. "mvn clean install -U") in the right project directory.
If you are on eclipse or STS please install and Use GC(GrepCode Plugin) ,some time you don't need to attach the source .zip file into your project path so GrepCode works fine for you.
I've had a related issue in connection with Glassfish server debugging in Eclipse.
This was brought about by loading the source code from a different repository (changing from SVN to GitHub). In the process, the wrong compiled classes were used by the Glassfish server and hence, the source and run time would be out of sync with break points appearing on empty lines.
To solve this, rename or delete the top folder of the classes directory and Glassfish will recreate the whole class directory tree including updating the class files with the correctly compiled version.
The classes directory is located in: /workspace/glassfish3122eclipsedefaultdomain/eclipseApps/< your Web Application>/WEB-INF/classes
In my case with tomcat projects I have checked project here:
Window - Preferences - Tomcat - Source Path - Add java projects to source path
In my case the Maven version of the other referenced project didn't match the version of the test project. Once they were the same, the problem disappeared.
When running in debug mode, click Edit Source Lookup after suspended from thread. At this point, we should be able to add the necessary project/jar which contains your source code.
After I added my current project in this way, and it solved my problem. Thanks
If you want to attach source code to any JAR by auto-downloading, try using this Eclipse plugin Java Source Attacher
I had this problem while working on java code to do process on a excel file containing a data set, then convert it to .csv file, i tried answers to this post, but they did not work.
the problem was the jar files themselves. after downloading needed jar files one by one(older releases) and add them to my project, "source not found" error vanished.
maybe you can check your jar files.
hope this would help.
this worked for me
right click on project -> Properties -> Deployment Assembly -> add your jar
Go to Debug configuration in eclipse and use below goal to run your application.
-Dmaven.surefire.debug
e.g
-Dmaven.surefire.debug exec:java
Well, here's what worked for me. I tried every possible solution on StackOverflow that there was. I tried changing my source location in the debug menu, I installed the m2e Eclipse plugin, I changed from embedded Maven, and I installed the run-jetty-run and nothing worked. Now, I will caveat that I was not trying to view an external person's source code, I just wanted to see my OWN code, but every time I "stepped in" to my methods that I wrote that were in MY project, I got the "Source now found" error.
After finally asking an expert, my issue was that the first thing Eclipse was doing was calling a ClassLoader, which you can see from the debug stack. All I had to do was F6 (step over) and then it took me back to my original call and then F5 (step in). And there was my code. Sigh...such a simple fix but an hour wasted.
For beginners,
There is a possibility that the jar file is a part of the project which you have not yet included in the Eclipse workspace.
For that, you need to know the project name of the jar file.
Say for example, its abc-18.0.0-SNAPSHOT.jar, it means that the project you are supposed to include in your workspace is abc.
I had the same issue with eclipse 2019-03 (4.11.0) and I was only able to solve this by doing the debugging via remote debugging instead of directly launching it in debug mode.
Attach source -> Add -> External Archive -> select the jar -> open -> done
the catch is look for the sources jar and attach this jar.
for example the jar ends with "-sources" Stax2-api-3.4.1-sources
sometimes these thing happens because of the version also like if you are using latest
version in that case it may arise try to use older version it will work.
I am trying to use Eclipse, Subversion and Maven for my projects and everyone is telling me never to check in the following files:
target/
.classpath
.project
.settings
But if I dont check them in and some other project checkouts the project from within Eclipse, Eclipse does not know what type of project it is.. Are we doing something wroung?
How do you work?
Eclipse has a plug-in for Maven; I believe it is called m2eclipse. After having it installed you can select Import from Maven project and select the pom.xml which will import your project to eclipse even if .project and .settings are not present. So there is no need for you to commit them to svn. This comes with the advantage of IDE neutrality; other members of your team may use Intellij IDEA or NetBeans without any concern.
Also Maven has a plug-in for eclipse; you can go where pom.xml is located, open a terminal and type mvn eclipse:eclipse and it will automatically generate .project and .settings.. However the first option is more recommended.
I had the same issue with eclipse, maven and git, so maybe it is helpful for you:
Try to setup your repo in svn and check it out, but don't import it.
You have to import the project over File -> Import -> Existing Maven Project into your workspace.
The last step is to share the project. Rightclick -> Team -> Share -> SVN -> and set the existing one as repo.
That's the way I handle this in Eclipse. Hope it's clear enough?
Btw you should not check in these file, because classpath and so on could be different on other machines.
I check in .classpath and .project but not very often. You do have to make sure that everyone who is working on the project has versions of eclipse that are close enough (including the particular plugins and eclipse features included). Sometimes you can get by with very different versions of eclipse if you make sure almost nobody checks those files in and everybody just mostly compares and manually updates those files from the version control when they are updated.
If you don't check them in, everybody has to create an empty project and then load the source files (and all the version control files or folders) into the project. If you are careful you can copy in those two files and then fool with the options settings to make them match.
Note that Maven helps a lot with this as it takes care of most of the content of the .classpath file.
The main reason not to check in those files are that the IDE's will very likely make changes to those files to suit your local dev environment. Which will probably cause conflicts and thus "broken" projects if everybody is committing their versions all the time.
That said, eclipse should have decent maven integration via the m2eclipse plugin (which I believe might be baked in by default these days).
Part of the idea behind Maven is exactly this - reproducible builds cross platform, cross IDE etc etc - so IDE specific files like that should not be required to build the project.
Importing the project with the m2eclipse plugin should sort things out nicely.
If you mean the other members check out the project and it doesn't work for them, they can check out the maven project separately without using eclipse and then import it into eclipse as an existing maven project using the m2eclipse plugin. This works cleanly without any problems (for me at least).
if everyone in your team is using Eclipse and it is agreed that the project will never use anything else, you may as weel check those files in. but it will make things kind of irritating if someone uses IntelliJ, Netbeans of other tooling or has his Eclipse very customized.
It depends.
Maven documentation explicitly says something like "Do not check in .project/.classpath/.settings/ because they can be regenerated from pom.xml". The later part of the sentence ("they can be regenerated") is not true, so the first part of the sentence (the advice) may or may not be OK, depending on the circunstances. Not every bit of the Eclipse configuration can be regenerated from the pom.xml, so my opinion is that the decission is based on a tradeoff between how much gain you get from it and being tied to the particular IDE.
So it depends.
For "community projects", where usually each developer will use different IDEs and different versions of the IDE, I would recommend not to check in those files. Otherwise, it would be a pain for developers not using your IDE and your version of the IDE.
For large "corporate project", IDE and IDE version are not free to be choosen by the developer but firmly dictated by the project management. So are dictated things such as compiler(1), code formatting, validating rules, warnings-and-errors configuration, custom in-house plugins configuration and many others. Many of those things cannot be set in pom.xml (nor should they because Maven is not and IDE, but a building tool). So in this case I would recomend to check in those files and blame the developer who complies, because he is trying not to follow the dictates.
(Notice that in this case I intentionally used words such as "dictate" and "blame" because the project management of a corporate project has not only the right but also de duty to "dictate" and "blame")
In the opposite side, for one-person projects, you do not have to worry about your colleages, so go check them in.
But the key is that you have to know your circunstances and the consecuences and decide yourself.
(1) No, "maven.compiler.source" is not the compiler to be used.
What is the purpose of Build Automatically option in Eclipse (Project-->Build Automatically)? Mine will always be checked. But when ever I have some java code changes I still have to do a full build. I was told that it should always be checked. I don't see any benefit in doing so. Please somebody explain.
Eclipse has a good answer on their website:
You have two modes of working: auto-build mode and manual build mode. By default, you are in auto-build mode and Eclipse takes care of compiling source files automatically. Builds occur automatically in the background every time you change files in the workspace (for example saving an editor). Auto-build is convenient because it means problems view, binaries, etc. are are up-to-date at all times. The downside is that in large workspaces auto-builds can be time-consuming if you are changing files in projects with lots of downstream dependent projects.
If auto-build is taking too long and is interfering with ongoing development, it can be turned off. Once in manual build mode, the user is in complete control over when builds occur and what gets built. Project > Build All (Ctrl+B) can be invoked at any time to trigger what auto-build was doing automatically. This allows you to build up a larger set of changes before invoking a build (Eclipse remembers which files have changed so that it does not have to do more work than required when you do ask for a build.
Note that when they say "auto-build mode" they mean if you have checked "Build Automatically", when they say "manual build mode" they mean you do not have "Build Automatically" checked.
Yes, you still have to do a build - but it's done automatically when you save (not an external build like an Ant build, but the "internal" build). If you didn't want to build on save, you'd uncheck the box. Having it build automatically makes some people nervous, I believe.
NOTE
For C/C++ users it's told (from help.eclipse.org):
By default, the Eclipse workbench is configured to build projects automatically. However, for C/C++ development you should disable this option, otherwise your entire project will be rebuilt whenever, for example, you save a change to your makefile or source files. Click Project > Build Automatically and ensure there is no checkmark beside the Build Automatically menu item.
Project - Disable Autobuild option does not always mean autobuild is off. For example "Makegood" test automation plugin will trigger autobuild when Preferences - Run/Debug - launching - (General opt) Build before launch is ON. So turn it off if manual build needed.
One thing that people didn't mention here (and it took a while for me to figure this out too) is that eclipse build (either automatic or manual) would basically follow what you have outlined in the project's "Java Build Path" source tab. So when a file is covered in that build source tab, when you change the file, it gets copied/compiled to the output folder that was specified for that directory/file.
One more difference is:
Most of the time while working on JSPs it helps me when checking "Build Automatically". It automatically picks up the changes in JSPs.
But if you make changes in your java classes/XMLs you need a manual build.
Since I'm using resin server which is run outside eclipse via command prompt, i prefer checking the option.
When i have my server setup in eclipse, i turn it off and use Publish on server.
This is the way i use and the answer is based on my experience.
If Build Automatically is checked, the IDE will automatically compile your Java code whenever you modify and save a file. This does not mean it will completely build and package your entire solution as if you were going to deploy it such as if you are working in a Web project on a WAR module. It basically really just compiles your code.
We have a pretty big project. We use ant for setting the environment. One of the things that happens during the ant script is that a jar is copied to the lib folder of a project. Then, we use ant tasks: eclipse.refreshLocal and eclipse.incrementalBuild so that the jar now copied will resolve compilation problems in the project that refer to it.
Unfortunately, the projects seem unsynchronized with the filesystem. Project > properties > build path shows that the jar is present (probably information that is refresh while looking at the propertiesw) but the incrementalBuild didn't do what we expected it to do.
Also, sometimes a project that depends on this jar and we refreshed and built it (through ant) has a single compilation error: "The project cannot be resolved until build path errors are resolved". In other times, the are many compilation errors indicating the project hasn't noticed the new jar.
When I build it through eclipse, it is ok.
I was worried that maybe there are circular dependencies between the projects, but it appears the are no such dependencies (Build properties: the circular dependencies option is set to "Error", and the are no errors of this form in the projects).
Anybody is fimiliar with the problem?
What is the proper way to deal with this problem?
Thank you for your help.
If you right click on the build.xml and select Run as → Ant Build... you'll see a tab called Refresh. Just check the option Refresh resources upon completion.
(I use this myself when generating code in an ANT xslt target and it works like a charm.)
You may also want to check Refresh automatically under Window → Preferences → Workspace
Try Cleaning the entire workspace and refresh :)
One solution which might work for you is to modify the Eclipse launch config for the Ant build (Run -> External Tools -> External Tools Config), and explicitly configure it to refresh the workspace (or parts of it) when the Ant build finished. This removes the need to perform the refresh from within the Ant script itself, and it always triggers the correct build reaction when the script completes.
Eclipse does not generally like it very much if you change files in its workspace from outside. There is an option in the Eclipse Preferences to automatically sync with the filesystem, but that can be very intense with regards to IO.
And it will probably still not solve all your problems, esp. when you change library jars.
Even considering skaffman's suggestion with the Refresh on build completion, I am not sure this would really improve your situation, but give it a try.
From my experience, realistically I would have yet to see a solution in a big setup that really works and makes life easier instead of just creating a different set of problems.